frame relay

Vanguard Managed Solutions

Vanguard Applications Ware Basic Protocols

Frame Relay Interface/Access

Notice

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Notice (continued)

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Information and software in this document are proprietary to Vanguard Managed Solutions (or its Suppliers) and without the express prior permission of an officer of Vanguard Managed Solutions, may not be copied, reproduced, disclosed to others, published, or used, in whole or in part, for any purpose other than that for which it is being made available. Use of software described in this document is subject to the terms and conditions of the Vanguard Managed Solutions Software License Agreement.

This document is for information purposes only and is subject to change without notice.

To comment on this manual, please send e-mail to [email protected]

Part No. T0106-02, Rev LPublication Code DSFirst Printing November 1998

Manual is current for Release 6.4 of Vanguard Applications Ware.

Frame Relay Interface/Access

Overview

Introduction Frame Relay support is offered in the basic Vanguard Applications Ware available for Vanguard products. Vanguard nodes are supported by two forms of Frame Relay:

• Frame Relay DTE Interface (FRI) FRI allows you to configure and operate Frame Relay DTE ports on Vanguard nodes. Frame Relay DTE ports allow the node to be connected to Frame Relay networks or other devices that provide a Frame Relay DCE service. With proper configuration, a Vanguard FRI port can also be directly attached to the FRI port of an adjacent Vanguard node. The use of FRI ports allows the node to pass LAN and serial protocol data streams over Frame Relay services.

• Frame Relay DCE Access (FRA) FRA allows you to configure and operate Frame Relay DCE ports on Vanguard nodes. Frame Relay DCE ports allow the node to provide Frame Relay network interfaces for attached devices. Depending on the configuration, FRA ports can provide Frame Relay network services and also provide for LAN and router connectivity for locally attached devices.

In This Manual Topic See Page

Frame Relay Interface (FRI) ......................................................................... 3Features ..................................................................................................... 4

Configuring the Frame Relay Interface (FRI) ............................................... 6Configure the FRI Port Record ................................................................. 7Configuring the FRI Station Record ......................................................... 19

Congestion Control for Frame Relay Stations............................................... 43Congestion Control with FRI Ports ............................................................... 45

Congestion Control for DTE..................................................................... 46Committed Information Rate (CIR) and Committed Burst Size (BC) . 46End-to-End Delay ................................................................................. 46Congestion Control Mode..................................................................... 46Maximum Information Rate (MIR) ...................................................... 47

Explicit Congestion Control...................................................................... 48Implicit Congestion Control...................................................................... 50

Traffic Shaping .............................................................................................. 51Traffic Shaping Typical Example.............................................................. 53

Frame Relay Transmission Fairness.............................................................. 54Auto-Learning Control Protocols .................................................................. 56Frame Relay Auto Learn and Remote DLCI Configuration ......................... 57

How It Works ............................................................................................ 58Sample Application................................................................................... 59Supported Platforms.................................................................................. 60Auto Learn DLCI Assignment .................................................................. 61

Frame Relay Loopback Detection ................................................................. 63Frame Relay Over ISDN ............................................................................... 64

Modes of Operation................................................................................... 66Sample Vanguard 6520/6560 Network Configurations ............................ 67Sample Vanguard 3xx/ 64xx Configurations ............................................ 69Frame Relay Same Port Backup ............................................................... 74

Frame Relay Interface/Access 1

In This Manual Topic See Page(continued)

Frame Relay SVCs ........................................................................................ 77SVC Operation .......................................................................................... 81

Outgoing Call Processing ..................................................................... 81Incoming Call Processing ..................................................................... 84Examples............................................................................................... 86

Sample Configuration Example ................................................................ 94SVC Connections On-Demand ................................................................. 102

Booting FRI Stations ..................................................................................... 105Examining FRI Configuration Records......................................................... 106

Port/Station/Channel Control Command .................................................. 108FRI Status/Statistics....................................................................................... 109

Detailed Port Statistics .............................................................................. 110Detailed FRI Station Statistics .................................................................. 117Detailed Link Statistics ............................................................................. 127CCS Statistics ............................................................................................ 129

Level 2 Statistics ................................................................................... 129Level 2 Detailed Statistics .................................................................... 130CC Call Summary................................................................................. 132Configure CCS L2 Trace Buffer ........................................................... 134Examine Level 2 Trace Buffer.............................................................. 136View Level 2 Trace ............................................................................... 140

Frame Relay Access (FRA)........................................................................... 141Call Connection for FRA Station .................................................................. 143Configuring the Frame Relay Access (FRA) ................................................ 145FRA Operations............................................................................................. 155

Boot Command ......................................................................................... 156Examine Command................................................................................... 157Non-Octet Aligned Errors and CRC Errors .............................................. 159Port/Station/Channel Control Command .................................................. 160

FRA Status/Statistics ..................................................................................... 161Detailed FRA Station Statistics................................................................. 167Detailed Link Statistics ............................................................................. 171

Frame Relay Concentrator............................................................................. 172Changing a Configuration Record for a Station on a Port ........................ 174N and D bit handling ................................................................................. 175Asynchronous A bit handling.................................................................... 177DE Bit Handling........................................................................................ 179Adding and Deleting PVCs....................................................................... 180

FRF.12 ........................................................................................................... 182FRF.12 and Third Party Products.............................................................. 185

FT1/FE1 Daughtercard Over Frame Relay ................................................... 186Configuring the T1/E1 Interface in a Frame Relay Network.................... 187T1/E1 Interface Statistics .......................................................................... 202Diagnostics................................................................................................ 205

2 Frame Relay Interface/Access

Frame Relay Interface (FRI)


Support Frame Relay Interface (FRI) supports:

• Frame Relay DTE Interface ports on Vanguard nodes.• Connecting multiple Vanguard nodes through Frame Relay (FR) networks.• Transmitting and receiving frames through Vanguard nodes, with Frame

Relay T1.617 with Annex G (X.25 encapsulation) or without (Bypass mode).• Configurable support of the ANSI Standard, T1.617 Annex D, LMI, and

Q.933 Annex A protocols.• Switched Virtual Circuits. Each FRI station may be configured to support

either network PVC or SVC circuits. PVC and SVC circuits may co-exist on the same port.

Number of Configured Stations

You can configure up to 254 Frame Relay stations on each FRI port and each station must be configured with a unique Data Link Connection Identifier (DLCI).

There are two types of FRI Station; Annex G or Bypass.

• An Annex G station supports the transmission of data that is encapsulated in X.25, and, is referred to as an X.25 logical link. Vanguard allows a maximum of 254 FRI logical X.25 links per FRI port. Each FRI Annex G station supports a maximum of 640 virtual circuits, 512 SVCs, and 128 PVCs.

• A Bypass station supports the transmission of data that is encapsulated by any means other than X.25, the most common method being IETF (RFC 1490). A maximum of 254 Bypass stations are allowed on an FRI port.

You can configure both Annex G and Bypass on the same port, but the maximum number of stations on any port is 254. Network topology, performance considerations, and memory constraints may limit the actual number of FRI stations per node. The total number of FRI or FRA stations configured depends on the Vanguard device.

Bandwidth The bandwidth of an FRI port is equal to the speed of the physical link, regardless of the number of logical links configured.


T0106-02, Revision L Release 6.4


Features

List of Features The FRI port provides the following features:

Feature Description

Annex G • Frame Delimiting, Transparency: When using FRI Annex G, data for multiple X.25 logical links can be transmitted over one physical link. This can be done by enveloping LAP-B frames for each X.25 logical link with a Frame Relay address header that identifies the Frame Relay Data Link Connection Identifier (DLCI).

• Retransmission of Frames (Annex G only):Upon detection of an out-of-sequence frame, Vanguard retransmits frames according to the LAP-B protocol.

• Annex G Support: FRI supports Annex G SVCs and PVCs.

Congestion Control • Explicit Congestion: If the FRI receives explicit congestion notification from the network for a particular Frame Relay station, it reduces the information rate for that station according to congestion notification procedures specified in the ANSI Frame Relay standard. The information rate is increased when the congestion condition is cleared.

• Implicit Congestion:Frame loss is also detected at the Annex G station level, and the information rate is reduced for that station when the frame loss condition is present.

Annex A/D/LMI FRI provides configurable support for:• ITU-T Standard, Q.933 Annex A for PVCs• Annex D Local In-channel Signalling protocol of ANSI

Standard T1.617• Local Management Interface (LMI)• Suppression of Management Protocol.

Support of these protocols enables the Frame Relay network to notify the FRI station of a Permanent Virtual Circuit (PVC) outage, and enables possible recovery from such a condition.

Bypass FRI supports Bypass stations, with RFC 1490 being the usual method of encapsulation. Bypass stations do not add X.25 overhead to the Frame Relay frame. This allows greater throughput but limited reliability

Auto Learn and Remote DLCI Configuration

FRI simplifies installation of Vanguard FRAD devices by providing automatic DLCI learning and remote configuration access to your Vanguard device.



Frame Relay over ISDN

The Frame Relay DTE Interface (FRI) in Vanguard products is extended over ISDN. This allows the Frame Relay DTE Interface to be configured as a Frame Relay virtual port for running over ISDN. It provides two types of connectivity over ISDN:

• Semi-Permanent:• Dial-On-Demand

For more information, refer to the “Frame Relay Over ISDN” section on page 64.

Frame Relay SVCs FRF.4 Implementation of Frame Relay SVCs is supported on FRI ports. This allows DLCIs to be connected, on-demand, via Frame Relay switched virtual circuits. (This is an optional feature. A software image can be built without SVC support.)

Feature Description (continued)



Configuring the Frame Relay Interface (FRI)


Introduction This section describes how to configure FRI on a Vanguard node.

There are essentially two parts to configuring FRI:

• Configuring the Frame Relay Interface Port record.• Configuring the Frame Relay Interface Station Record.

These procedures, the records, and the parameters are explained in detail below.



Configure the FRI Port Record

Introduction This section explains how to configure the FRI Port Record.

CTP Menus Figure 1 identifies shows how to access the FRI Port Record and configurable parameters:

Figure 1. Configure FRI Port Record

Main Menu

Configure

Port

MUXX25FRI PAD

*Port Type

Connection TypeClock SourceClock SpeedInvert Tx ClockFrame Sequence CountingPacket Sequence CountingControl Protocol SupportControl Protocol OptionsControl Protocol RoleDiscard Control OptionsHigh Priority StationMaximum Voice Bandwidth bits per secUNI Segmentation StateUNI Segmentation Size When Voice is PresentUNI Segmentation Size When Voice is not PresentUNI Segment Delay TimeoutUNI Received Packet Size CheckSegment Size When Voice is PresentSegment Size When Voice is Not Present

Port Number

FRA

T391/nT1 Poll TimerT392/nT2 Verification TimerN391/nN1 Full Status Polling CycleN392/nN2 Errors During Monitored EventsN393/nN3 Monitored EventsStarting SVC DLCI NumberSubscriber NumberCore Parameter Maximum Frame (FMIF) SizeLAPF Retransmission TimerLAPF Maximum Number of RetransmissionsLAPF Maximum Number of Outstanding I FramesLAPF Connection Verification TimerSetup Timer (T303)Disconnect Timer (T305)Release Timer (T308)Call Proceeding Timer (T310)




Configuration Procedure

Perform these steps to configure a port as an FRI Port Record:

FRI Port Parameters

These are the FRI Port Record parameters.

Unless otherwise indicated, changes to Port parameters require a Port boot to take effect. Parameters identified with an asterisk (*) require node boot for changes to take effect.

NoteIf you have enabled Ease of Configuration, you need to boot only the port to make changes to the parameters marked with an asterisk. For more information, refer to the Ease of Configuration section in the introductory portion of the Basic Protocols Manual, (Part Number T0106).

Step Action

1 Select Configure from the CTP Main menu.

2 Select Port from the Configure menu.

3 At the prompt, enter the number of the port you want to configure.

4 Set Port Type equals FRI, and configure the FRI Port record parameters.

5 Configure the FRI Port Record parameters as they appear. Refer to the section below for details about each parameter.

*Port Number

Range: 1 to 54

Default: 1

Description: Specifies the port number for the Frame Relay Interface port you are selecting.

*Port Type

Range: NULL, PAD, X25, FRI, FRA

Default: X25

Description: Specifies the type of port you are configuring.• NULL: Reserves the port for future use.• PAD: Allows the port to be connected to a device such as a

terminal, personal computer, or printer.• X25: Allows the port to be connected to another, usually

high-speed, device such as a Vanguard product or a network.• FRI: Used to configure a Frame Relay Interface Port.• FRA: Used to configure a Frame Relay Access Port.



Connection Type

Range: SIMP, SIMPb, DTR

Default: SIMP

Description: Specifies the control signal handshake and clocking required for a connection to be made to this port.

• SIMP: Simple, no inbound control signals required.• SIMPb: Simple, no data transmission control signals required. • DTR: dedicated, requires the Data Terminal Ready signal.

For descriptions of other Connection Types, refer to the Vanguard Configuration Basics Manual (Part Number T0113).

Clock Source

Range: INT, EXT, EXTINT, EXTLP

Default: EXT

Description: Specifies which clock source is used.• INT: Internal clock source (Vanguard provides clocking).• EXT: External clock source (external device provides

clocking).• EXTINT: Internal receive and external transmit clock source

(DCE only).• EXTLP: External receive and loopback clock source

(DTE only). EXTLP must be configured with EXTINT.

Clock Speed

Range: 1200 to 2048000

Default: 64000

Description: Specifies the port speed in bps.

NoteThe actual speed may be limited by the type of hardware and the “clock source” parameter.




Invert Tx Clock

Range: No, Yes

Default: No

Description: Specifies whether the phase of the transmit clock is to be inverted.Set to Yes when using an X.21 electrical interface, Clock Source equals EXT, Clock Speed is set to a high value, and the cable is less than 6 meters (20 feet).

NoteThis parameter only appears on the Vanguard 6560, and only on physical Frame Relay ports.

Frame Sequence Counting

Range: NORM, EXT

Default: NORM

Description: Specifies the numbering scheme used by information frames (that is, the LAPB modulo count). This parameter applies to all Annex G stations configured for this port.

• NORM: Normal sequencing (Modulo 8).• EXT: Extended sequencing (Modulo 128).

NoteYou must set this parameter to the same value at both the local and remote Vanguard FRI ports.

Packet Sequence Counting

Range: NORM, EXT

Default: NORM

Description: Specifies the numbering scheme for data packets (that is, the packet level modulo count). Packet sequence occurs on a per-channel basis. This parameter applies to all Annex G stations configured for this port.

• NORM: Normal sequencing (Modulo 8).• EXT: Extended sequencing (Modulo 128).

NoteSet this parameter to the same value at both the local and remote FRI ports.



Control Protocol Support

Range: Annex-D, Annex-A, LMI, AUTO, NONE

Default: NONE

Description Determines the type of control protocol support enabled for Frame Relay PVC management.

• LMI, Annex-D, and Annex-A: report on the status of Frame Relay PVC connections.

• Auto: allows the unit to automatically discover the control protocol (Annex-D, Annex-A, or LMI).

Control Protocol Options

Range: NONE, ASYNC, NBIT, DBIT, DTE_ONLY

Default: NONE

Description: Specifies the options used to control the PVC management protocol:

• NONE: No option selected• ASYNC: The port sends/receives asynchronous A-bit if it is

performing Network side protocol functionality. In addition, this option suppresses the sending of unsolicited Full STATUS messages.

• NBIT: The port sends and accepts N-bit messages. The port ignores N-bit in messages if this value is not specified.

• DBIT: The port sends and accepts D-bit messages. This forces ASYNC to be specified (DBIT+ASYNC).

• DTE_ONLY: This forces a DTE Interface Type to remain as DTE, suppressing changes to BI_DIR mode on receipt of STATUS ENQ.

NoteThe Range DTE_ONLY applies to Annex A and Annex D control protocols only.

Control Protocol Role

Range: DTE, DCE

Default: DTE

Description: This option controls whether the PVC management protocol acts like a DTE or DCE.

• DTE: This port takes on the DTE or User Side role• DCE: This port takes on the DCE or Network Side role.




Discard Control Options

Range: NONE, DEBIT

Default: NONE

Description: Specifies the options used to control the discard action resulting from congestion within the node.

• NONE: No additional actions are taken.• DEBIT: Frames marked DE are discarded when the node

indicates onset buffer pool congestion. Frames marked DE are discarded by a station when the station perceives onset of adjacent port congestion.

High Priority Station

Range: 0 to 254

Default: 0

Description: Specifies a station whose PVC status has priority over all other stations when FRI Same Port Backup is enabled. When the network reports this DLCI inactive, an alternate connection over a backup link is attempted. To specify no station, enter 0 (zero).

Maximum Voice Bandwidth bit per sec

Range: 0 to 2048000

Default: 2048000

Description: Limits the bandwidth, in bits per second, (including overhead) for voice traffic passing through this Frame Relay port. To prevent any voice traffic from passing through this port, enter 0 (zero).

UNI Segmentation State

Range: Enabled, Disabled

Default: Disabled

Description: Enables FRF.12 Local UNI Segmentation. The peer must be set to the same value.

• Enabled - Enables UNI Segmentation.• Disabled - Disables UNI Segmentation.



UNI Segment Size When Voice Is Present

Range: 64, 128, 256, 512, 1024

Default: 64

Description: UNI Segment size when voice is present. This effects the transmit path only.

UNI Segment Size When Voice is not Present

Range: 64, 128, 256, 512, 1024, 2048, 4096, Disable

Default: Disable

Description: UNI Segment size when voice is not present. This effects the transmit path only.When set to Disable, the selection does not effect the packet size. UNI segmentation header will be inserted only.

UNI Segment Delay Timeout


Default: Disabled

Description: A packet is discarded on segment delays of more than 10 seconds. This is on the receive path only.

UNI Received Packet Size Check


Default: Disabled

Description: A check is performed to determine if the packet size is larger than the maximum frame size parameter configured in the Node Record.

• Enabled - The packet is discarded if the packet received is larger than the configured maximum frame size parameter.

• Disabled - The packet is accepted if the received packet is larger than the configured maximum frame size parameter.




Segment Size When Voice is Present

Range: 32, 64, 128, 256, 512, 1024

Default: 64

Description: Specifies the maximum frame segment size (in bytes) used to split or segment data traffic when both data and voice traffic are transported on this FRI port.

Segment Size When Voice is Not Present

Range: Disable, 32, 64, 128, 256, 512, 1024, 2048, 4096

Default: Disable

Description: Specifies the maximum frame size of segmented voice data packets when voice is not active on this port.

T391/nT1 Poll Timer

Range: 5 to 30

Default: 10

Description: This is the link integrity verification timer. The port sends status enquiry messages to the network every T391 seconds.

T392/nT2 Verification Timer

Range: 5 to 30

Default: 15

Description: This is the timer for verification of the polling cycle. The port expects status enquiry messages every T392 seconds. This only applies when PVC management is bi-directional.

N391/nN1 Full Status Polling Cycle

Range: 1 to 255

Default: 6

Description: Specifies the Full Status polling cycle. The port uses this parameter when it is running the user side of PVC management protocol. It sends a Full Report STATUS ENQUIRY message to the network every N391 polls.



N392/nN2 Errors During Monitored Events

Range: 1 to 10

Default: 3

Description: Specifies the error threshold. This is the number of errors during N393 events that cause stations related to the event to be declared inactive. Set this value to be less than or equal to N393.

N393/nN3 Monitored Events

Range: 1 to 10

Default: 4

Description: Monitored events count for measuring N392. N392 errors during N393 events cause the station to be declared inactive. Set this value to be greater than N392.

Starting SVC DLCI Number

Range: 16 to 1007

Default: 16

Description: Specifies the lowest DLCI used for outbound calls when a station is configured with the parameter Information Element Negotiation set to DLCI. The configured number is the lowest value of DLCI which any FRI station specifies in SETUP messages if it is configured with stations that initiate calls. Some attached equipment (switching nodes and Frame Relay networks) may not allow the DTE to specify a DLCI. If the DLCI number is not to be included in the SETUP message, the parameter Information Element Negotiation should not be specified.This number is always used for incoming calls. Incoming calls are not accepted if they specify the use of a DLCI below this value.

NoteA value of zero (0) disables SVC procedures on this port.




Subscriber Number

Range: 0 to 16 decimal digits

Default: (blank)

Description: All stations using this port use this value for their calling address Information Element (IE). The valid formats of this entry are:

• xxxxxxxx• Exxxxxxxx• Xxxxxxxxx

Where:xxxxxxxx represents the address of the station, E/X represents the numbering plan for the address with E=E.164 and X=X.121. E or X can be upper or lower case, must be the first character and, if absent, E is assumed.

NoteIf blank, this parameter is not used.

Core Parameter Maximum Frame (FMIF) Size

Range: 1 to 4096

Default: 2100

Description: This parameter is used when a station has the parameter Information Element Negotiation set to LLCP.

• For outbound calls: the station specifies the value for the Link Layer Core Parameters Information Element Frame Mode Information Field (FMIF) parameter and uses the value configured here.

• For incoming calls, the LLCP Information Element must be present and must be less than or equal to this configured value. The value of FMIF configured here only controls the contents of the information element for the purpose of making and filtering calls and does not enforce the frame size on frames on the operating DLCI of the SVC.

LAPF Retransmission Timer (T200)

Range: 1 to 255

Default: 15

Description: Specifies the maximum time (in 1/10 second increments) that the DTE waits for an acknowledgment of a transmitted Information frame. The DTE continues retransmissions at an interval of T200 until the tries count expires or proper acknowledgment is received from the attached equipment.



LAPF Maximum Number of Retransmissions (N200)

Range: 0 to 16

Default: 3

Description: Specifies the maximum number of times the DTE retransmits to recover from a T200 timeout condition. If this count is reached, the DTE declares the LAPF link to be down and initiates link establishment procedures.

LAPF Maximum Number of Outstanding I Frames (k)

Range: 1 to 32

Default: 7

Description: This is the maximum sending window size which is the maximum number (k) of sequentially numbered I frames that may be out-standing (unacknowledged) at any given time. The recommended values are shown below.

• Line Speed less than 16 kbps, for window size of 3 k• Line Speed greater than 16 kbps, for window size of 7k

LAPF Connection Verification Timer (T203)

Range: 0 to 255

Default: 30

Description: The idle timer (T203) represents the maximum time (in seconds) allowed without frames being exchanged. If the link remains idle for this period of time, the DTE sends a supervisory frame with the poll bit set.Set this timer to zero (0) to disable it.

Setup Timer (T303)

Range: 1 to 60

Default: 4

Description: Specifies the maximum time (in seconds) allowed without a response to a SETUP sent by a station. Upon expiration, the SETUP message is retransmitted and the timer restarted. The call to cleared upon the second expiration of the timerThis value applies to all SVC stations defined for this port.




Disconnect Timer (T305)

Range: 1 to 255

Default: 30

Description: Specifies the maximum time (in seconds) allowed without a response to a DISCONNECT message sent by a station. Upon expiration, a RELEASE message is sent. This value applies to all SVC stations defined for this port.

Release Timer (T308)

Range: 1 to 60

Default: 4

Description: Specifies the maximum time (in seconds) allowed without a response to a RELEASE message sent by a station. Upon expiration, the RELEASE message is retransmitted and the timer is restarted. The call is cleared upon the second expiration of the timer. This value applies to all SVC stations defined for this port.

Call Proceeding Timer (T310)

Range: 1 to 255

Default: 30

Description: Specifies the time (in seconds) after a Call Proceeding response (to a Setup message) that a call is cleared if a Connect, Disconnect, or Release message is not received. This value applies to all SVC stations defined for this port.



Configuring the FRI Station Record

Introduction This section explains how to configure the FRI Station Record.

Menu example Figures 2 and 3 shows how to access the FRI Station Record and configurable parameters.

• Figure 2 shows the FRI Station record when the parameter Station Type = Bypass.

• Figure 3 shows the FRI Station record when the parameter Station Type = Annex G.

Figure 2. FRI Bypass Station Record

Port NumberStation Number*Station Type (Bypass)Station Circuit Type (SVC)Call ControlCall Retry IntervalCall Attempts CountAUTD Idle Timer IntervalCall Retry IntervalCall Attempts CountAUTD Idle Timer IntervalInformation Element NegotiationStation SubaddressCalled Party NumberCalled Party SubaddressCommitted Information RateMinimum Committed Information RateCommitted Burst SizeExcess Burst SizeEnd-to-End Transit DelayCongestion Control ModePeak data link util. monitoring interval sizeEnd-to-End Segmentation StateEnd-to-End Segmentation TypeEnd-to-End Segmentation Size When Voice is PresentEnd-to-End Segmentation Size When Voice is not PresentEnd-to-End Segment Delay TimeoutEnd-to-End Received Packet Size CheckFrame SegmenterMax Inbound QueueMaximum Information Rate (MIR)

Port NumberStation Number*Station Type (Bypass)Station Circuit Type (PVC)DLCICommitted Information RateCommitted Burst SizeEnd-to-End Transit DelayCongestion Control ModePeak data link util. monitoring interval sizeEnd-to-End Segmentation StateEnd-to-End Segmentation TypeEnd-to-End Segmentation Size When Voice is PresentEnd-to-End Segmentation Size When Voice is not PresentEnd-to-End Segment Delay TimeoutEnd-to-End Received Packet Size CheckFrame SegmenterMax Inbound QueueVoice Header Insertion(Cannot be seen in Annex G)

When:Station Type = Bypass Stations Circuit Type = SVC

When:Station Type = Bypass Stations Circuit Type = PVC

Main Menu Configure FRIStations




Figure 3. FRI Annex_G Station Record

Main Menu Configure

Port NumberStation Number*Station Type (Annex G)Station Circuit Type (SVC)Call ControlCall Retry IntervalCall Attempts CountAUTD Idle Timer IntervalInformation Element NegotiationStation SubaddressCalled Party NumberCalled Party SubaddressCommitted Information RateMinimum Committed Information RateCommitted Burst SizeExcess Burst SizeEnd-to-End Transit DelayCongestion Control ModeVoice Congestion Control ModeLink AddressNumber of PVC ChannelsStarting PVC Channel NumberNumber of SVC ChannelsStarting SVC Channel NumberNumber of SVC Voice ChannelsInitial FrameT1 Transmission Retry TimerT4 Poll TimerN2 Transmission TriesK Frame WindowW Packet WindowP Packet SizeData Queue Upper ThresholdData Queue Lower ThresholdRestart TimerReset TimerCall TimerClear TimerPeak data link util. monitoring interval sizeX.25 OptionsRestricted Connection DestinationCUG MembershipBilling RecordsEnd-to-End Segmentation StateEnd-to-End Segmentation TypeEnd-to-End Segmentation Size When Voice is PresentEnd-to-End Segmentation Size When Voice is not PresentEnd-to-End Segment Delay TimeoutEnd-to-End Received Packet Size CheckFrame SegmenterMaximum Information Rate (MIR)

Port NumberStation Number*Station Type (Annex G)Station Circuit Type (PVC)DLCICommitted Information RateCommitted Burst SizeEnd-to-End Transit DelayCongestion Control ModeVoice Congestion Control ModeLink AddressNumber of PVC ChannelsStarting PVC Channel NumberNumber of SVC ChannelsStarting SVC Channel NumberNumber of SVC Voice ChannelsInitial FrameT1 Transmission Retry TimerT4 Poll TimerN2 Transmission TriesK Frame WindowW Packet WindowP Packet SizeData Queue Upper ThresholdData Queue Lower ThresholdRestart TimerReset TimerCall TimerClear TimerPeak data link util. monitoring interval sizeX.25 OptionsRestricted Connection DestinationCUG MembershipBilling RecordsEnd-to-End Segmentation StateEnd-to-End Segmentation TypeEnd-to-End Segmentation Size When Voice is PresentEnd-to-End Segmentation Size When Voice is not PresentEnd-to-End Segment Delay TimeoutEnd-to-End Received Packet Size CheckFrame Segmenter

When:Station Type = Annex G

Stations Circuit Type = SVC

When:Station Type = Annex G Stations Circuit Type = PVC

FRIStations



Configuration Procedure

To configure a port as an FRI Station record, perform these steps:

FRI Station Record Parameters

These are the FRI Station Record parameters.

NoteUnless otherwise indicated, changes to Station parameters require a Station boot to take effect. Parameters identified with an asterisk (*) require node boot for changes to take effect.

Step Action

1 Select Configure from the Main menu.

2 Select FRI Stations from the Configuration menu.

3 Enter the port number, when prompted, on which you want to configure stations.

4 Enter the station number, when prompted, that you want to configure.

5 Configure the FRI Record parameters as they appear. Refer to the section below for details about each parameter

Port Number

Range: 1 to 54

Default: 1

Description: Specifies the physical port position at the rear of the unit and is also the reference number for the port record. The port number selected must be for a Frame Relay Interface port.

Station Number

Range: 1 to 254

Default: 1

Description: Identifies the station being configured




*Station Type

Range: Annex G, BYPASS

Default: Annex G

Description: Identifies the type of station you are configuring.• Annex G: this station uses X.25 signalling for layer 3. Annex

G adds packet header and LAP-B header to the frame for reliability checking between FRI stations. It supports X.25 SVC or PVC. Annex-G stations support other ports that are passing serial protocols, such as SNA HPAD and TPAD ports, or PAD ports.

• BYPASS: this station bypasses layer 3. Access Protocols provide their own reliability checking.

*Station Circuit Type

Range: PVC, SVC

Default: PVC

Description: Specifies the station circuit type for the Frame Relay line.• PVC: the station operates on its assigned DLCI as a PVC• SVC: The station operates on a given DLCI as an SVC.

Call Control

Range: AUTO, AUTD, RECV, CNORM

Default: RECV

Description: Controls the calling behavior of the SVC station.• AUTO: The station automatically initiates a Frame Relay

SVC call on power up• AUTD: The station initiates a Frame Relay SVC call on-

demand of data to transmit• RECV: The station can be used to receive inbound Frame

Relay SVC calls from attached network equipment• CNORM: The station can be used to receive inbound Frame

Relay SVC calls from attached network equipment or initiate a Frame Relay SVC call when the Annex G station requires an X.25 SVC connection

NoteThis parameter only appears if the parameter Station Circuit Type is set to SVC.



Call Retry Interval

Range: 1 to 255

Default: 4

Description: Specifies the time interval (in one second increments) between call attempts that a station configured to initiate an SVC call uses. If a call attempt fails, either because there was no response to the SETUP message or the response was a RELEASE, the station waits this amount of time before sending the next SETUP message.

NoteThis parameter only appears if the parameter Station Circuit Type is set to SVC and parameter Call Control is set to AUTO, CNORM, or AUTD.

Call Attempts Count

Range: 0 to 255

Default: 3

Description: Specifies the number of contiguous call attempts that a station configured to initiate an SVC call makes to establish the call. If this count expires, the station does not make any further call attempts. A station (or port or node) boot is required to re-initiate call attempts.A value of 0 means the station makes call attempts indefinitely.

NoteThis parameter only appears if the parameter Station Circuit Type is set to SVC and parameter Call Control is set to AUTO, CNORM, or AUTD.

AUTD Idle Timer Interval

Range: 10 to 255

Default: 40

Description: Specifies the idle time, in seconds, allowed for a FRI station to remain idle. If the station using the SVC passes no data during this time period, the SVC is cleared. If the SVC is cleared and the station attempts to send data, an SVC is established for the station.

NoteThis parameter only appears if the parameter Station Circuit Type is set to SVC and parameter Call Control is set to AUTD.




Information Element Negotiation

Range: NONE, DLCI, LLCP, TPIE

Default: NONE

Description: This allows the listing of Information Elements or their parameters to be used for negotiation in a SETUP/CONNECT message as follows:

• DLCI: If the station initiates a call, it selects the DLCI to use for the call. The value is included in the DLCI Information Element and specifies the lowest available value that is at or above the value of the port parameter Starting SVC DLCI Number. This configured value is not used for inbound calls.

• LLCP: If the station initiates a call, it places the Link Layer Core parameters Information Element in the call setup frame. For incoming calls, this value causes the incoming Link Layer Core Parameters to match or be bounded by the configured values for this station.


Station Subaddress

Range: 0 to 4 characters

Default: station number

Description: Specifies the stations subaddress. This is included in the outgoing SETUP message Calling Party Subaddress IE. Incoming SETUP messages, with a Called Party Subaddress IE of this value, are directed to this station. In the IE, the Type of Subaddress is encoded NSAP and the Even/Odd indicator is even. The subaddress field is prefixed with an ISO AFI indicating IA5 character string (x’04’). If blank, no subaddress IE is included in the outgoing call.




Called Party Number

Range: 0 to 16 characters

Default: (blank)

Description: This is the address of the destination station, in the appropriate numbering plan, to which a call is placed by this station. The valid formats of this entry are:

• xxxxxxxx• Exxxxxxxx• Xxxxxxxxx

Where:xxxxxxxx represents the address of the station, E/X represents the numbering plan for the address with E=E.164 and X=X.121. E or X can be upper or lower case, must be the first character and, if absent, E is assumed.

NoteSet to (blank) if the station is to receive calls.


Called Party Subaddress

Range: 1 to 255

Default: 4

Description: Specifies the destination stations subaddress. It conforms to the same numbering plan as defined in the Calling Party Number.





DLCI

Range: 0, 16 to 1007

Default: 0

Description: Specifies the Data Link Connection Identifier (DLCI) as the unique identifier for the station on the FRI port. The value must match the DLCI configured on the Frame Relay networking node. A zero (0) entry invokes the Auto Learn mode on powerup. When the node is in Auto Learn mode, DLCI numbers provided by the network are automatically assigned to all available FRI stations.

NoteDLCI numbers 0 to 15 and 1008 to 1023 are reserved for management of the FRI link according to Frame Relay Protocol Standards

NoteThis parameter does not appear when the parameter Station Circuit Type is set to PVC.

Committed Information Rate (CIR)

Range: 0 to 2048000

Default: 16000

Description: Throttles data on FRI for congestion control. When congestion first occurs, the outbound data rate drops immediately to the CIR rate. It also specifies the rate (in bps) that the Frame Relay network agrees to transfer information under congested conditions.

Minimum Committed Information Rate (MinCIR)

Range: 0 to 2048000

Default: 16000

Description: Specifies the minimum rate (in bps) that the Frame Relay network agrees to transfer information under congested conditions for this FRI Station. The value throttles the data for congestion control purposes and cannot be greater than the link speed



Committed Burst Size (BC)

Range: 0 to 4096000

Default: 16000

Description: Specifies the maximum amount of data (in bits) that the Frame Relay network agrees to transfer over a time interval (T), where T equals a Committed Burst Size/Committed Information Rate used for congestion control purposes. The BC must be greater than 1/20 of the Committed Information Rate.

Excess Burst Size (BE)

Range: 0 to 4096000

Default: 16000

Description: This parameter is negotiated during the call establishment phase of Frame Relay SVC calls. It has no effect on data transfer after a call is established.


End-to-End Transit Delay (ETE)

Range: 1 to 65535

Default: 50

Description: Specifies the estimated delay from one end of the network to the other. The ETE delay is used to determine how fast to remove an FRI station from a controlled state.




Congestion Control Mode

Range: NORMAL, DISABLE, CONG, LIMIT

Default: NORMAL

Description: Specifies the method of congestion control. When the attached network signals congestion by sending frames to the FRI port with the BECN bit set, the port enters a controlled sending state.

• NORMAL: Congestion control is normal. Upon receipt of the first BECN bit, the maximum controlled transmission rate goes to CIR. Receipt of additional BECN bits forces the controlled transmission rate to values lower than CIR.

• DISABLE (OFF): Never enter a Controlled State.• CONG: Always in a Controlled State. Stays at CIR or lower

data rate.• LIMIT: Congestion control is normal but limits the data rate

to no lower than CIR.

Maximum Information Rate (MIR)

Range: 0 to Maximum Access Rate

Default: 0

Description: Specifies the station Maximum Information Rate. The purpose of this parameter is to reduce chances for congestion when the local access rate is greater than the remote one. This parameter has to be set to a value equal to or greater than CIR and less than the local interface access rate (in order for the average outgoing information rate to match remote interface access rate). If the entered value is less than CIR, CIR will apply. If it is greater than the interface access rate, packets are transmitted at the maximum possible rate determined by the interface access rate. Response to network congestion is determined by the Congestion Control Mode parameter. When this parameter set to 0 it disables MIR control and the station transmits according to Congestion Control Mode parameter.

NoteThis parameter is shown only when Congestion Control Mode parameter is set to NORMAL, DISABLE or LIMIT. Perform a sta-tion boot to have changes to this parameter take effect.



Voice Congestion Control Mode

Range: DISABLED, ENABLED

Default: DISABLED

Description: Specifies the method of voice congestion control.• DISABLED (OFF): Voice congestion control disabled.• ENABLED: The station is forced into congestion when a

voice call is detected.When this parameter is enabled and a voice call is detected, the change in time (Tc) is forced to 50msec and the Bc is forced to 1/20 CIR.

Link Address

Range: DTE, DCE

Default: DTE

Description: Specifies the type of link address: DTE or DCE for the Annex G station. The link address setting must be set to the opposite value at the remote Annex G station at the Vanguard FRI port.

• DTE: The logical link DTE address is (A).• DCE: The logical link DCE address is (B).

NoteThis parameter only appears if the parameter Station Type is set to Annex G.

Number of PVC Channels

Range: 0 to 128

Default: 0

Description: Specifies the number of logical channels used for Permanent Virtual Circuits. The total number of PVC channels on a link should be as small as possible. You must configure PVC connections in the PVC Table.





Starting PVC Channel Number

Range: 1 to 4095

Default: 1

Description: Specifies the starting logical channel number for the Permanent Virtual Circuits on this link. If the parameter Number of PVC Channels is equal to 0, this parameter is ignored.


Number of SVC Channels

Range: 0 to 512

Default: 16

Description: Specifies the number of logical SVC channels on this link. The total number of SVC channels on a link should be kept as small as possible.


Starting SVC Channel Number

Range: 0 to 4095

Default: 1

Description: Specifies the starting logical channel number for the SVCs on this link. If the parameter Number of SVC Channels is 0, this parameter is ignored.




*Number of Voice SVC Channels

Range: 0 to 15

Default: 0

Description: Specifies the number of logical voice channel SVCs. The total number of voice and data channels on a station (logical link) should be as small as possible.


Initial Frame

Range: SABM, DISC, NONE

Default: SABM

Description: Specifies the first frame that is transmitted during link startup:• NONE: Do nothing (the other end starts).• SABM: Send SABM.• DISC: Send DISC then SABM.


T1 Transmission Retry Timer

Range: 1 to 254

Default: 80

Description: Specifies the time (in increments of 1/10 of a second) after a frame is transmitted and no ACK is received before the frame is retransmitted.This must be set to a value less than the parameter T4 Poll Timer.

NoteThis applies to Annex G stations only.




T4 Poll Timer

Range: 0, 10 to 255

Default: 90

Description: Specifies the time (in increments of 1/10 of a second) that an idle link is probed for assurance of connection to the remote device. To disable this parameter, set it to 0. This must be set to a value greater than the parameter T1 Transmission Retry Timer.


N2 Transmission Tries

Range: 1 to 20

Default: 10

Description: Specifies the number of times Vanguard attempts to complete a transmission before declaring the link down.


K Frame Window

Range: 1 to 15

Default: 7

Description: Specifies the number of unacknowledged frames that can be outstanding. The largest possible value allows the highest possible throughput. The setting for this parameter should be the same for the devices on both ends of the link.




W Packet Window

Range: 1 to 15

Default: 7

Description: Specifies the maximum number of packets that can be outstanding. This controls the data flow across an interface and the amount of packet buffering. The values must be the same for both ends of the link.


P Packet Size

Range: 32, 64, 128, 256, 512, 1024

Default: 128

Description: Specifies the maximum default packet size for inbound and outbound calls on this FRI station when packet size is not negotiated. The values must be the same for both ends of the link.


Data Queue Upper Threshold

Range: 5 to 15

Default: 5

Description: Specifies the maximum number of data packets that a logical channel on this link, queues for transmission before invoking flow control to the adjacent channel.





Data Queue Lower Threshold

Range: 0 to 4

Default: 0

Description: Specifies the minimum number of data packets that a logical channel on this link has queued for transmission when it releases flow control to the adjacent channel.


Restart Timer

Range: 5 to 255

Default: 180

Description: Specifies the time (in seconds) that the device waits before sending a restart request again.


Reset Timer

Range: 5 to 255

Default: 180

Description: Specifies the time (in seconds) that a device waits before sending a restart request again.




Call Timer

Range: 5 to 255

Default: 200

Description: Specifies the time (in seconds) that a device waits for the response to a call request. When the timer expires, the call is cleared.


Clear Timer

Range: 5 to 255 (seconds)

Default: 180

Description: Specifies the time (in seconds) that the device waits before sending a clear request again.


Peak data link util monitoring interval size

Range: 0 to 240

Default: 0

Description: Specifies the time (in 64 second increments) used when monitoring peak data link/CIR (Committed Information Rate) utilization.To disable this parameters, set to zero (0).

End-to-End Segmentation State


Default: Disabled

Description: Enable end-to-end segmentation. If enabled, then the peer must be enabled as well.




End-to-End Segmentation Type

Range: FRF12, VanguardMS

Default: FRF12

Description: Indicates the type of segmentation that is being used. The peer must be configured to the same setting.

• FRF12 - FRF.12 End-to-End Segmentation is used.• VanguardMS - VanguardMS End-to-End Segmentation is

used.

End-to-End Segment Size When Voice is Present

Range: 64, 128, 256, 512, 1024

Default: 64

Description: The End-to-End segment size when voice is present. This effects the transmit path only.

NoteThis parameter appears when the End-to-End Segmentation Type parameter is set to FRF12.

End-to-End Segment Size When Voice is not Present

Range: 64, 128, 256, 512, 1024, 2048, 4096, Disable

Default: Disable

Description: End-to-End segment size when voice is not present. This effects the transmit path only.




End-to-End Segment Delay Timeout


Default: Disabled

Description: Discards a packet if any segment delay is more than 10 seconds. This effects the transmit path only.


End-to-End Received Packet Size Check


Default: Disabled

Description: Check if the packet size is larger than the configured Maximum Packet Size parameter in the node record.

• Enabled - Discard the packet if larger than the configured maximum size.

• Disabled - Accept the packet if they are larger than the config-ured maximum size.


X.25 Options

Range: NONE, CUG, CAUSE, HOLD, INL, DELAY

Default: NONE

Description: Defines operating characteristics of the X.25 port. • NONE: No options are selected.• CUG: Represents a Closed User Group.• CAUSE: Passes cause and diagnostic codes on outboard

packets.• HOLD: Holds calls upon a link restart.• INL: Proprietary link exchange is done only to another

Vanguard.• DELAY: Enable Delay and Path Trace on this link. Link must

be connected to a Release 4.xx node.You can select several of these settings by summing the values (CUG+HOLD+...).





Voice Header Insertion


Default: Enabled

Description: This parameter determines whether the Voice Header is inserted in the front of the voice payload. It takes effect only when the Station Type is Bypass and the Segmentation Type is FRF.12. Otherwise, the Voice Header is inserted.

• ENABLE - Voice Header is inserted• DISABLE - Voice Header is not inserted

NoteThis parameter appears when:Station Type = BypassEnd-to-End Segmentation State = EnabledEnd-to-End Segmentation Type = FRF.12

Restricted Connection Destination

Range: 0 to 32

Default: (blank)

Description: Specifies the port destination of calls inbound from the port. This parameter overrides Route Selection Table record entries. To disable this parameter, set this parameter to (blank).


NotePerform a Station boot to implement changes to this parameter.

CUG Membership

Range: 0 to 8 two-digit numbers

Default: --,--,--,--,--,--,--,--

Description: Specifies membership to Closed User Groups (CUGs). A port may be a member of up to 8 CUGs. Each CUG membership must be a 2-digit number (00 to 99), separated from other groups by a comma. To indicate that the channel is not a member of a CUG, press the minus key twice (– –).




Billing Records

Range: OFF, ON

Default: OFF

Description: Specifies that billing records are created. No billing records are created when set to OFF.


Frame Segmenter

Range: DISABLED, ENABLED

Default: DISABLED

Description: Determines if the station supports the Frame Segmenter Header. Enable this parameter if the Frame Relay port is configured to pass voice traffic.

Max Inbound Queue

Range: 100 to 2500, 0

Default: 2500

Description: Specifies the maximum number of frames from the network which can be queued in a Bypas station. Use a small value for applications which experience long delays due to excessive growth of the Bypass inbound queue.

NoteThis parameter only appears if the parameter Station Type is set to Bypass.




Window Subtractor

Range: 0 to 63

Default: 0

Description: Specifies the point in the receive window that the layer 3 acknowledgment is to be sent when there are not any packets to send in the reverse direction. The acknowledgment is sent when the number of packets equivalent to the W Packet Window minus the Window Subtractor has been received. If the W packet Window is 32 and the window subtractor is 8, the layer 3 acknowledgment is sent once 24 packets have been received.Setting the Window Subtractor to a non-zero value when INL or INL+INLB are set has no impact on the functionality of the routing loop detection feature of INL. It only effects functionality when the layer 3 acknowledgment is sent.If INL is specified and the subtractor is zero, the router uses the previous setting of 2.If INL+ INLB is specified and the subtractor is zero, the router will send an Acknowledgment for every packet received. This is also what occurs if INL nor INLB are not specified and the subtractor is zero.You should increase the value of the subtractor when you are using high speed end-to-end connections or when path delays are unusually high. This sends the acknowledgments sooner so the remote window stays open and the remote node can continue to send data without being stopped (waiting for an acknowledgment). The "Window Subtractor" Value is dependent on the "W" (packet) window setting and interacts with many other settings and factors such as the speed of the line, the "K" (frame) window setting, circuit propagation delay, etc. Tuning can result in CPU utilization savings and higher throughput.

NoteRefer to the following table of Recommended Window Settings.



Recommended Window Settings

These recommendations were arrived at in a controlled environment. In links with long delays adjustments may be required. A general rule would be to be bring the Window Subtractor value close to or equal with the “W’ Packet window. This effectively allows the acknowledgments to be sent out faster accommodating the added delay.

The new Window Subtractor parameter is downward compatible with previous releases. It can be set independently at one end of the link without effecting the remote node that may not have this parameter. In addition to the recommendations in the table above the following two parameters should be always be set as shown below:

• Data queue upper threshold = 15• Data queue lower threshold = 4

NoteThe Vanguard 7300 W Packet Window parameter’s default has been changed from 2 to 7.

Mis-match in packets

A mis-match in packets can cause connections to work improperly. For example, when a 6.1 release software loaded node is connected to a 6.0 release software loaded node is connected to each other via FRI Annex-G with default settings, this causes mismatch in packet layer window size and the connection does not work properly causing large delays or no data going through. Setting the W Packet Window parameter to be the same in the two nodes will allow the connection to work properly.

Annex G/X.25 Window Guidelines

Link Description Recommended Window Settings Recommended Window

Subtractor

K (Frame) W (Packet)

8 Mbps Serial 63 30 25

4 Bps Serial 30 20 15

2 Mbps Serial 30 20 15

E1 30 20 15

1536 Kbps Serial 25 15 10

T1 30 20 15

512 Kbps 15 10 6

256 Kbps 10 7 4

128 Kbps 10 7 4

64 Kbps 10 7 4

64 Kbps 10 7 4




PPPoFR Parameters

The following parameter appears on the FRI Station for PPPoFR:

.

Stacking Support


Default: Disabled

Description: This parameter specifies whether protocol stacking support is enabled to receive stack connection requests. In the case of PPPoFR, this allows FRI station to receive stack connection request initiated by PPP.

NoteThis parameter needs to be enabled to support PPP over Frame Relay application. This parameter only appears for Bypass station


Congestion Control for Frame Relay Stations


What Is It? Congestion control for Frame Relay networks consists of real time mechanisms used to prevent and recover from congestion when the Frame Relay network is stressed with traffic. Stresses can occur when the network is subjected to momentary peaks in the offered traffic or when a node or line failure causes unplanned loading on some part of the network.

Controlling Traffic Volume

To control the amount of traffic, the network uses a form of explicit notification. At the onset of congestion, the network can signal end users that there is congestion. When a transmitting user sees the notification of congestion, it lowers its transmission rate until the congestion notifications are no longer received. The congestion is often due to a temporary excess load. Therefore, when there is no further indication of congestion, a transmitting user can increase its send rate. In most cases, the sender takes advantage of the statistical gain in throughput that the network can achieve and send queued data continually in bursts at a rate greater than the committed information rate (CIR) of the Frame Relay channel.

A sending user can also detect congestion by implicit means. A sending user can detect retransmissions, at the data link level using LAP-B procedures for stations configured as Annex G. Retransmissions are necessary due to frames being dropped by a Frame Relay network in a congested state. In this case, the sender should reduce its rate until the congestion clears.

In both implicit and explicit congestion control, the assumption is that the sender cooperates by pacing the rate of transmission at proper levels. In some cases, users are unable to perform in this way or are configured to ignore congestion. If the sender is transmitting at greater than the committed information rate, then the Frame Relay network can discard frames to avoid congestion. Frames that are marked as DE (discard eligible) or that are received by the Frame Relay network such that they are in excess of the committed information/burst size rates can be discarded by the network.

In severe congestion, frames that are not marked DE or that are received within subscribed committed information/burst size rates can be discarded.

In Vanguard, congestion control performed via the CLLM (Consolidated Link Layer Management) message is not supported.




DE-Bit Handling Setting the port parameter Discard Control Options to DEBIT enables the port to discard frames marked DE, if there is an onset of congestion.

There are two conditions for the congestion onset:

• Usage of global buffer pool by all applications in the node - The operating system provides a message to applications indicating the onset of congestion. The message is sent to all applications that register with the buffer manager. The FRA and FRI ports register with the buffer manager and receive these indications. The buffer manager also sends a message when the buffer pool is highly utilized (depleted).

• Buildup of queues within a given port - Indicates that the port is becoming congested.

When the onset of global buffer pool congestion is notified, and the port is enabled to discard DE marked frames, it discards all frames marked DE that it receives or has in its inbound queue. The port continues to discard received frames until the buffer manager signals the buffer pool that usage has gone below onset of congestion.

Congestion Within a Port

Congestion within a port is detected by the amount of inbound buffer usage that the port experiences. This buffer usage is on a per PVC basis. When a PVC station receives frames from its line, it stores the frames until they are transmitted to the internally connected station, if that station is busy.

The size of this station queue is monitored. If the queue size threshold is reached, all frames marked with DE that are received by the station are discarded.

The FRI port has an additional congestion detection mechanism on its outbound queue. The size of this queue is also measured and thresholds are provided to detect the onset of congestion. When the upper threshold is reached, the mechanism sends a message to the inbound port station to discard DE marked frames. The message is called Block.

As frames are transmitted, the size of the buffer decreases. When the lower threshold is reached, an Unblock message is sent to the internally connected station to stop discarding DE marked frames.

The concentrator application does not, on its own, mark any port frame DE.


Congestion Control with FRI Ports


Introduction An FRI port has two different types of stations: Bypass and Annex G. There are two types of congestion notification used to control station transmission rates; Explicit and Implicit.

• Explicit Congestion notification is done by the attached network sending frames to the FRI station with the Backward Explicit Congestion notification (BECN) bit set in the frame header. This notifies the FRI station that the network is congested for the corresponding DLCI. Both Annex G and Bypass stations can be configured to respond to Explicit Congestion notification.

• Implicit Congestion notification is the process of an Annex G station detecting lost frames. Frame loss is detected when the LAP-B Annex G station is forced to retransmit a frame. Only Annex G stations can respond to Implicit Congestion notification.

Under normal conditions, neither the Annex G nor the Bypass stations set the Discard Eligible (DE) bit.

Data Rate An FRI station normally sends frames at the maximum rate available (line speed). It is possible for the station to exceed its committed rate. Usually, this is a temporary situation and statistically the station sends at or below its committed rate. However, if the network is experiencing congestion, then the implicit or explicit congestion mechanism causes the station to enter a controlled send state and lower its rate of transmission to cooperate with the network in congestion control.

An Annex G station that is in a controlled send state, sends frames that carry voice traffic. This occurs even if transmission causes the send rate to exceed the controlled rate. These frames are not buffered and are sent as quickly as possible. Excess rate voice frames are sent with the DE bit set.




Congestion Control for DTE

For a Frame Relay DTE Interface (FRI) port, there are five configurable parameters related to congestion control:

• Committed Information Rate (CIR)• Committed Burst Size (BC)• End-to-End Delay• Congestion Control Mode• Maximum Information Rate (MIR)

Committed Information Rate (CIR) and Committed Burst Size (BC)

The values to use for the CIR and BC are those to which the Frame Relay port and its DLCIs have subscribed. If this port connects to a Frame Relay carrier, these parameter values are provided by the carrier and should be set accordingly.

NoteThese parameters cannot be tuned; they are set by the provider of the Frame Relay network at subscription time.

End-to-End Delay

The End-to-End delay parameter determines the value of the internal step count parameter used to reduce the transmission rate when congestion is measured by the station. The End-to-End Delay value can be estimated and supplied by the provider of the Frame Relay service. It can also be measured, but this is difficult to do and the estimate is usually sufficient.

These parameters are configured on a per station basis. Excessive frame loss due to congestion indicates the step count used in reducing the transmission rate may be too large. This situation can be improved by adjusting the End-to-End Delay parameter.


You use the Congestion Control Mode parameter to define how the station handles congestion notification. The FRI station detects the Frame Relay network congested state when it receives a frame from the network with BECN bit set to one (1). As a sender, it constantly monitors this bit in frames received from the Frame Relay network. If the BECN bit is detected as being set, the transmitter reduces its rate of transmitting data bits. Note that the rates are the maximum rates of transmission. Obviously, such rates are achieved only if the transmitter has data constantly queued for transmission on the station.

You use the Congestion Control Mode parameter to control the handling of congestion notification for both explicit and implicit congestion notification.



Maximum Information Rate (MIR)

Introduction In order to control the station outgoing information rate and provide traffic shaping capabilities, a station configuration parameter Maximum Information Rate (MIR) has been created. The MIR parameter is accessible only when Frame Relay station configuration parameter Congestion Control Mode is configured as NORMAL, DISABLE or LIMIT. Valid values for this parameter are between CIR and the local interface access rate. While a network is uncongested, the station maximum average transmission rate is determined by this parameter. Measurement Interval Tc is forced to be in range 50 to 200ms.This reduces burstiness and further reduces a chance for congestion. Large Tc values can cause large gaps between packets, because packets are sent at the beginning of the interval. Smaller Tc values smooth traffic by spreading one big burst over several time intervals. This reduces the chance for long delays of voice packets caused by previously accumulated data packets in network switches. When the MIR parameter is set to the default value 0, Traffic Shaping is disabled and the station rate and operation are equal to the existing rate and operation. When MIR is enabled station state is Controlled.

NoteVoice packets and packets having priority PRI_EXP_DROP, will be excepted by the rate control. The packets will not be queued or discarded even when the rate is higher than MIR.

For more Traffic Shaping information, refer to “Traffic Shaping” section on page 51.




Explicit Congestion Control

Introduction Both Annex G and Bypass stations permit the use of explicit congestion control. Explicit Congestion Control is the process of reducing a station’s transmission rate when the attached network sends frames to the FRI port, with the BECN bit set. The Congestion Control Mode parameter determines how a station reacts to the BECN.

Normal Congestion Control

This mode of congestion control is obtained by setting the parameter Congestion Control Mode to NORMAL. A station is initially in the uncontrolled state and can transmit data when data is available. This means that the maximum number of characters allowed is only limited by the link speed. Upon receiving the first BECN from the network, the allowed transmission rate is immediately reduced to ensure the CIR is not exceeded, and the station goes into a controlled state. In the controlled state, a step count algorithm calculates two parameters:

Step Count equals (CIR x End-to-End Delay) / max packet size

Delta-T equals Committed Burst Size / CIR

Where max packet size equals a nominal value of 2088 bits, the other values are taken from the stations configured values with the CIR value in bits per second and End-to-End Delay in seconds

NoteStep Count cannot be less than 4 or grater than 255

These parameters are used to measure and control congestion and to either reduce the rate further or increase the rate (re-enter uncontrolled state). Delta-T is the average time in which a specific number of characters are allowed to be transmitted.

While in the controlled state:

• If the number of additional BECNs received (consecutive frames with the BECN bit set) is greater than, or equal to the Step Count, the maximum transmission rate allowed is reduced to 5/8 of CIR. This applies if the allowed rate is between 5/8 CIR and CIR.

• If the number of additional BECNs received (consecutive packets with the BECN bit set) is greater than, or equal to the Step Count, the maximum transmission rate allowed is reduced to 1/2 of CIR. This applies if the allowed rate is between 1/2 CIR and 5/8 CIR.

• If the number of BECNs received (consecutive packets with the BECN bit set) is greater than, or equal to the Step Count, the maximum transmission rate allowed is reduced to 1/4 of CIR. This applies if the allowed rate is between 1/4 CIR and 1/2 CIR.

• If further BECN bits are received, the transmission rate is not set below 1/4 CIR (that is, the lowest transmission rate that can be set).

The Frame Relay network stops sending frames with the BECN bit set when it recovers from its congested state. The FRI station counts the number of consecutive frames received without the BECN bit set. When the number of frames with BECN set to zero exceeds (Step Count)/2, it increases the allowed transmission rate in increments of 1/8 CIR and again counts the number of consecutive frames with BECN set to zero to repeat the increment process. Once the transmission rate reaches CIR, the network leaves the controlled state.



The NORMAL mode is used in most cases when the port is attached to a Frame Relay network provider. It gives a measure of protection from frame loss if the Frame Relay network becomes so congested that it loses frames even if the transmission rate was near CIR bounds. If lost frames requires retransmission, then this is the best mode since retransmission into a congested network causes further congestion.

Disable Congestion Control

This mode of congestion control is obtained by setting the Congestion Control Mode to DISABLE. This disables the FRI station rate reduction congestion management mechanism and you can use this value when frame loss by the network is not an issue. It allows the transmitter to send at its highest rate without regard to possible congestion frame loss.

If frame loss is an issue with the application using this DLCI, it usually employs a retransmission scheme to detect and resend lost frames. If this is the case, be aware that disabling congestion control may actually reduce throughput. Retransmissions into an already congested network only adds to the congestion, and congestion likely becomes so severe that overall throughput goes below a level that would be achieved if the transmitter reduced its rate using the congestion notification mechanisms.

NoteAnnex G stations always operate with a LAP-B procedure and retransmit on detecting frame loss. This mode might not be desirable for such stations.

Congested Congestion Control

This mode of congestion control is obtained by setting the Congestion Control Mode to CONG. A station is always in the controlled mode, that is, the maximum transmission rate allowed never exceeds the CIR. In this controlled state, the same rate control algorithm applied in the NORMAL mode is used to further control the transmission rate if BECN bits are received.

This mode allows the transmission rate to be set to a maximum of CIR, even when there is constant data queued for transmission. This mode is useful in situations where the attached network discards frames which are received at a rate greater than CIR.

NoteAn important example of the use of this mode would be a Frame Relay network configured to discard frames that are in excess of CIR.

Limit Congestion Control

This mode of congestion control is obtained by setting the Congestion Control Mode to LIMIT. A station is initially in the uncontrolled state, that is, the maximum transmission rate allowed is limited only by the link speed. Upon receiving the first BECN from the network, the maximum transmission rate allowed is reduced to CIR, and the station goes into the controlled state. The maximum allowed transmission rate is never reduced below CIR, regardless of the number of BECN bits received. Upon receiving [(Step Count)/2] consecutive frames without the BECN bit set, the station goes back into the uncontrolled state.

This mode can be selected when the Frame Relay network is not usually subjected to congestion conditions. Occasional light congestion experienced by the network causes the station to reduce the transmission rate to the CIR value and no lower.




Implicit Congestion Control

Introduction For implicit congestion control on Annex G stations, any time the station needs to retransmit (frame loss / REJ), it informs the FRI port congestion control mechanism. When congestion control receives this indication, it immediately reduces the maximum allowed transmission rate to 1/4 of CIR and goes into the controlled state. The same rate recovery algorithm used for NORMAL congestion control is used to get out of the controlled state. This consists of receiving [(Step Count)/2] consecutive packets from the network with the BECN bit clear to increase the allowed transmission rate by 1/8 of CIR, and repeating this process until the CIR rate is achieved. A final [(Step Count)/2] count of frames with BECN set to zero moves the station into the uncontrolled state.

Annex G stations using implicit congestion also use explicit congestion control. In effect, the detection of frame loss is simply an additional method of sending a station into the controlled state, at an allowed rate of 1/4 CIR. Once the station enters a controlled state, the recovery process is the same, that is, counting consecutive frames with BECN set to zero.


Traffic Shaping

Traffic Shaping

Introduction Traffic Shaping is a mechanism for controlling the rate of outgoing traffic in order to minimizes network packet loss. It delays excess PVC traffic by queuing it when traffic throughput is higher than expected and matches its transmission to the speed of the remote, target interface. Traffic shaping also avoids overloading a remote link by smoothing the traffic and regulating the average rate on an outgoing interface.

Feature Summary Data Traffic Shaping features:

• Outgoing data traffic rate control in a range between the configured CIR an the line access rate

• Seamless transition from Traffic Shaping mode to configured Congestion Control Mode when the network is congested

• Support for existing Voice Bandwidth Allocation mechanism

Traffic Shaping - Rate Control

A configuration parameter Maximum Information Rate (MIR) is available to control the station outgoing information rate and provide traffic shaping capabilities. When the Vanguard Frame Relay station parameter Congestion Control Mode is configured as NORMAL, DISABLE or LIMIT you have the option to limit the station outgoing information rate to some pre-determined value, Maximum Information Rate (MIR). The value of MIR shall be equal to or greater then CIR and equal to or less than the local interface access rate. When this option is disabled the station transmits (without rate control) at maximum line speed.

Traffic Shaping - Measurement Interval

When the Traffic Shaping feature is enabled, Measurement Interval Tc is forced to be in range of 50 to 200ms. When calculated value Tc = Bc/CIR is greater than 200ms, Tc is set to 200ms and the burst size Bmir (Bmir=Tc*MIR) will be calculated accordingly. The number of data bits, transmitted per Tc will be always kept equal to or less then Bmir.

Data throughput should not be affected by value of Tc. When Bmir is small, it is likely that just few packets can be transmitted per Tc and that some significant portion of the bandwidth may be unused. Since you are not allowed to send more than Bmir bits per Tc, the effective bandwidth is lesser than MIR. When voice is present, this effect is minimized due to the small size of voice packets as well as segmentation of data packets. When the variation in packet size is small, MIR shall be based on that size. For instance, when segmentation is enabled and End-to-End Segment Size When Voice Is Not Present is different then Disabled the MIR shall be selected to allow integer multiple of segment (including all headers) size per Tc. In such a way, when voice is not present, the data throughput will be closest to the selected MIR value. When the size of some packet is bigger than allowed Bmir, a big packet is allowed to pass by crediting in advance, to avoid packet flow blockade. When the size of the packet is bigger then Bmir it will be transmitted more than Bmir data bits per Tc, but the multi interval average rate will be kept no more than the MIR.



Traffic Shaping

Traffic Shaping in Presence of Network Congestion

When the network indicates congestion by sending packets with set BECN bit, configured Congestion Control Mode applies. When using NORMAL and LIMIT, when the network stops sending packets with set BECN bit, the data information rate increases gradually, up to MIR.

Traffic Shaping in Presence of Voice

Traffic Shaping applies to data traffic only. Voice packets will not be delayed or dropped because of Traffic Shaping. When there is voice traffic through PVC, a decision must be made if data throughput or voice quality is the priority. To avoid voice degradation, due to traffic shaping, the Voice Congestion Control Mode parameter shall be enabled. When both Traffic Shaping and Voice Congestion Control Mode parameters are enabled and voice is present, Voice Congestion Control algorithm will apply (there is no traffic shaping for voice). Required bandwidth is reserved for voice on that PVC and the remaining bandwidth is used for data. At instances when voice is not present, data traffic is shaped. The data rate is then controlled by shaping the mechanism up to MIR, regardless of the Voice Congestion Control status. When Voice Congestion Control Mode is disabled, voice and data will share bandwidth determined by MIR. In all cases, when there are more bits to be transmitted than allowed, data is queued and voice is transmitted.


Description

NORMAL The information rate shall be reduced to CIR and then gradually updated to CIR/4 while the network congestion lasts.

LIMIT The information rate shall be reduced to CIR and is kept at that value while congestion lasts.

DISABLE The information rate shall not change. The station will keep sending packets at MIR.


Traffic Shaping

Traffic Shaping Typical Example

Network congestion is formally defined as “Traffic in excess of network capacity”. Consequences of congestion are long delays, as result of packet queuing in network switches and packet loss, as result of buffer overflow.

Source and destination line speed mismatch in presence of bursty traffic is a frequent cause of network congestion. Figure 4 is an example of an asymmetrical network. The central site (Node A) has a T1 line into the cloud, while the remote (branch or telecommuter) site has a lower speed (56 Kbps). The central site sends packets at a much higher rate than the remote line can transmit to the destination node (the ingress rate is higher than the egress one). This results in a bottleneck (packet queuing and eventually dropping) in the egress switch. A possible solution is rate limiting at the central site, so you do not exceed the remote side.

Configuring the MIR for the corresponding stations in the node A, to 56k, limit their outgoing rates and prevent packet loss.

Figure 4. Traffic Shaping - Asymmetrical Network

Traffic Shaping is a mechanism for controlling the rate of outgoing traffic in order to minimizes network packet loss. It delays excess PVC traffic by queuing it when traffic throughput is higher than expected and matches its transmission to the speed of the remote, target interface. Traffic shaping also avoids overloading a remote link by smoothing the traffic and regulating the average rate on an outgoing interface.

Node A

Node B

Node C

Node D

T1

56K

56K

56K

Frame Relay Network



Frame Relay Transmission Fairness


Introduction The transmission of frames is regulated on each DLCI so that one DLCI carrying intense traffic and/or large frames, does not effect other DLCIs on the same link. Effectively, this shares the link transmission bandwidth amongst all DLCIs and ensures that, at the very least, each DLCI obtains its CIR.

Transmission Fairness is beneficial to those stations that are constantly transmitting. Stations that transmit at infrequent intervals typically operate well below their CIR and, as such, transmit their data when necessary.

Transmission fairness does not imply a priority level. When the occasional frame is queued for transmission by a station, the frame waits its turn in the queue. Having a large CIR, with respect to other stations, does not mean that the frame is moved up in the queue. This would however, apply to voice packets.

Since no priority is associated with transmission fairness, there is no overall performance change when using pre-5.1 release software. This is especially true of applications using a low window number for its interworking with a remote. A typical example of this is an application that sends a single message and waits for an acknowledgment before sending the next message.

Sharing Link Bandwidth

The sharing of link bandwidth is in proportion to the stations CIR. The amount of additional bandwidth given a station is determined by its configured CIR, and the sum of CIRs from all transmitting stations.

When uncommitted bandwidth is available, it is divided between all transmitting DLCIs.

Zero CIR Configuration

When zero-CIR stations are configured, the Clock Speed parameter (found under FRI Port Configuration) must be set to a value representing the actual link operating speed. This also applies to ports that are externally clocked.

Since all DLCIs with a non-zero CIR may periodically saturate the link, DLCIs with a zero CIR are not guaranteed bandwidth on the link.

These two formulas apply to non-congested conditions (when the station is not in a controlled sending state). For the purposes of the calculations, only actively transmitting stations are considered. Nt denotes the total number of such stations while the number of such stations with CIR set to zero.

• The fraction of link bandwidth available to each zero CIR station (Fz) is calculated here

• The fraction of link bandwidth available to each non-zero CIR station (Fn) is calculated here:

Fz = 1- (total CIR / link speed)Nt

Fn = Station CIRtotal CIR * (1 - Fz * )



ExampleFor the purposes of this example, assume that a node has the following conditions:

• FRI port has a link speed of 64 kbps.• All stations have a CIR of 16 kbps.• Three Bypass stations carrying LAN traffic (stations 1, 2, and 3) and one

Annex G station carrying serial traffic (station 4).Station 1 is idle.Stations 2 through 4 are actively transmitting data.

Since each station is configured with the same CIR, the amount of bandwidth given each active station is the same:

(16 x 64)/(16+16+16) = 21.3 kbps



Auto-Learning Control Protocols

Auto-Learning Control Protocols

Introduction This section explains how Frame Relay can auto-learn the Control Protocol.

Description When you set the parameter Control Protocol Support to AUTO, Frame Relay can auto-learn these three control protocols:

• Annex D• Annex A• LMI

Auto-learning occurs when any of the following occurs:

• the node is booted• the applicable FRI port is enabled or booted• the currently running PVC management Control Protocol detects a failure on

the Frame Relay lineWhen any of these occurs, the FRI port enters an auto-learning state by initiating the auto-learn algorithm. It remains in this state until the specified Control Protocol is recognized.

NoteAuto-learning the control protocol and auto-learning DLCI values can be done on the same FRI port

Configuration Considerations

Keep these factors in mind when using this feature:

• To use this feature, the network or equipment to which the FRI port is attached must be running one of the Control Protocols listed above (Annex D, Annex A, LMI). This feature cannot auto-learn the absence of a Control Protocol.

• When the auto-learn algorithm is running, all PVC stations are inactive and cannot pass data. Stations configured to auto-learn their DLCI value must wait until the Control Protocol is determined. After the Control Protocol is determined, DLCI values are assigned to stations configured to auto-learn their DLCI value and the status of DLCIs reported by the attached equipment is recognized. If the link is up and DLCI status is active, data can pass.

• The auto-learning algorithm requires at least one successful exchanges of STATUS ENQUIRY and STATUS messages before it learns the Control Protocol. This time must be added to the time it takes to declare the Frame Relay link up.


Frame Relay Auto Learn and Remote DLCI Configuration


Introduction The Frame Relay Auto Learn and Remote Configuration features simplify our Vanguard products FRAD devices by providing automatic DLCI learning and remote configuration access to Vanguard devices.

These features simplify the installation of Vanguard devices in a Frame Relay network by eliminating the need for a service technician to visit the location of remote devices for initial configuration. With Frame Relay Auto Learn and Remote Configuration, all you have to do to get your Vanguard nodes up and running in a Frame Relay network is to power up the nodes, and make the physical connections to the network. Vanguard devices automatically learn and assign DLCI numbers from the network and make virtual connections with the Frame Relay network using default FRI ports and protocol parameters.

NoteDo not use more than one auto-learn DLCI on any given Frame Relay port. In some link outage conditions, a DLCI can be re-assigned to a different station number than the one to which it was first assigned when the link originally came up.

Requirements You must adhere to the following conventions when you use Frame Relay Auto Learn and Remote Configuration to assign DLCI numbers to FRI ports:

• Your Frame Relay network link must support LMI, Annex-D, or Annex-A control protocols.

• Your FRAD devices must be configured for either Annex-D, LMI, or Annex-A. The factory default is Annex-D.

Limitations If, for some reason, an Annex-G station is not configured on the FRI port for your remote node, you cannot log into the remote node’s CTP. You can access the node’s CTP by reconfiguring the FRI port to set Station 1 to Annex-G or by defaulting the node through the front panel at the remote site.

SNMP Support No SNMP support is available for this feature.

Adding Stations If you configure subsequent FRI ports on a remote node, the default port automatically provides one station with the Auto Learn feature. For example, if you configure Port 3 on the remote node for Frame Relay, the node automatically provides a default Annex-G station. The default control protocol for the port is Annex-D.




How It Works

Frame Relay DLCI Auto Learn

The Frame Relay DLCI Auto Learn feature lets a VanguardMS FRAD device automatically learn the DLCI(s) available from the Frame Relay network and configure itself to utilize these DLCIs.

With Frame Relay DLCI Auto Learn, your FRAD:

• Learns the number of PVCs available on a specific Frame Relay network port.• Learns the network-assigned DLCI numbers for each available PVC.• Assigns each of the DLCIs to an FRI port station which is configured as

available for Auto Learn.• Makes the DLCI/FRI station available for use.

Station statistics indicate when a station is in the Auto Learn mode. Auto Learn assigns DLCI numbers in ascending numeric order to the available FRI port stations. An Auto Learn FRI station remains in the Auto Learn mode until assigned a network DLCI number.

Auto Learn generates an alarm when there are unassigned network DLCIs available.

If Auto Learn stations are unassigned because there are more stations configured than there are PVCs, or because there is a mismatch between the FRAD and Network PVC management protocols, the stations remain in the Auto Learn mode and no alarms are generated.

Remote Configuration

The Remote Configuration feature makes it possible for a VanguardMS FRAD device to automatically connect to a Frame Relay network at powerup and to be configured from a remote location. Each FRAD comes from the factory with ports 1 and 2 configured as FRI. The default ports each provide a single Auto Learn Annex G station. Using the Frame Relay Auto Learn feature, the FRAD assigns the first available DLCI to the Annex-G station. You can use a remote terminal to connect to the FRAD device CTP to put the finishing touches on the configuration.

Remote Configuration features include:

• Default FRI port. (See the “Hardware Platform Default Settings” section on page 60” under “Supported Platforms” for details on port locations for each platform.)

• Default Annex-G station for FRI ports.• Default Annex-D link control protocol for FRI ports.• DLCI Auto Learn as a default on all FRI port stations.

Factory Default Settings

The factory default settings for Vanguard products provide two default FRI ports with one Annex-G station each configured with the new DLCI Auto Learn feature. This lets remote nodes power up and begin communicating with the central site. Each remote node is connected to the Frame Relay network through a factory default FRI port. When the remote node is powered on, it learns the available DLCIs and assigns the first DLCI to the default Annex-G station. Once a remote node is autoconfigured, enabled, and active, you can connect to the remote node’s CTP from the central site using an X.25 call.



Sample Application

Sample Application Figure 5 shows how Frame Relay Auto Learn and Remote Configuration can help you simplify the process of building a network or adding new Vanguard devices to an existing network.

Figure 5. Example of Remote Configuration and Auto Learn

Configuring Remote Nodes

In this example, the network has several remote nodes feeding into a single host computer. Each remote node requires at least one DLCI. Normally, you would have to completely configure each remote node before deploying it in the network, or send a service technician out to the remote sites to configure each node.

However, with Auto Learn and Remote Configuration, you can install Vanguard nodes with factory default configurations to remote locations in your network. Using the Frame Relay Auto Learn feature, the nodes assign DLCIs automatically upon powerup and connect to the network.

You can remotely configure each node from a terminal using, for example, a Vanguard node to connect to the Frame Relay network, as shown in Figure 5.

When the configuration of the remote devices is complete, the central site terminal and access device (Vanguard 300 FRAD as shown in Figure 5) can be disconnected from the Frame Relay network and the central site FEP connected for normal operation.

You can configure nodes remotely from a PC connected to a Vanguard for access to the Frame Relay network.

SNAFEP

Vanguard

These remote nodes automatically assign DLCIs and connect to the Frame Relay Network via default Annex G Station configured in each node.

Vanguard

Vanguard

Vanguard

Frame Relay

Terminal

SDLC

SDLC

SDLC

SDLC

Central Site

60




Supported Platforms

All Platform Support

All Vanguard products support Frame Relay Auto Learn and Remote Configuration. These features are fully compatible with networks supporting LMI, Annex-D, and Annex-A management protocols. After installing operating software on your node, the Remote Configuration and DLCI Auto Learn features are readily available for use on all FRI ports.

Hardware Platform Default Settings

This table describes default port configurations and support for the Auto Learn and Remote Configuration features on Vanguard products:

This Platform... Defaults... And...

Vanguard 100 Ports 1 and 2 to FRI automatically invokes DLCI Auto Learn.

Vanguard 100PC Ports 1 and 2 to FRI automatically invokes DLCI Auto Learn.

Vanguard 200 Port 1 to X.25. You have to configure a port for FRI.

automatically invokes DLCI Auto Learn after the port is configured to FRI.



Vanguard 34x Ports 1 and 2 to FRI automatically invokes DLCI Auto Learn.


Vanguard 6520 Port 1 to X.25. You have to configure a port for FRI.


6500PLUS Port 1 to X.25. You have to configure a port for FRI.




Auto Learn DLCI Assignment

Overview Auto Learn assigns DLCI numbers for stations on any given port during node, port, and station boot. There are two modes of DLCI assignment for FRI port stations:

• Static• Dynamic

Static DLCI Assignment

Static DLCI assignment reads the DLCI number statically configured by the operator in the FRI station record, and assigns this number to the station during the boot operation. The DLCI number corresponds to a network PVC configured with the same DLCI number. There is no Auto Learn procedure used with statically configured stations.

Dynamic DLCI Assignment

Dynamic DLCI assignment relies on the Annex-D, Annex-A, or LMI protocol for providing DLCI number(s) for PVC circuits on a network port. The existing DLCI configuration parameter in the FRI station record is used to indicate static or dynamic DLCI configuration modes. If you configure the entry as zero (0), the FRI station enters the dynamic DLCI configuration mode when it is booted. If you configure the FRI station DLCI parameter with a valid DLCI value (16 to 1007), the station enters the static configuration mode where the configured DLCI value is used for that station.

Incremental Assignment of DLCI Numbers

When one or more stations on an FRI port are in DLCI Auto Learn mode, Auto Learn assigns DLCIs, in increasing numeric order, to the FRI port stations available. Auto Learn continues to assign DLCIs until all network DLCIs are assigned, or until the number of configured FRI port stations is exhausted, whichever happens first.

If there are more network DLCIs than configured FRI stations, Auto Learn generates an alarm, warning you that there are network DLCIs available, but that they are unassigned to FRI stations. You should increase the number of stations configured for the port to avoid this situation.

Static and Dynamic Configurations

If your network contains stations with statically configured DLCIs and stations configured for Auto Learn mode, these assignment rules apply:

• All statically configured stations are assigned their respective network PVC DLCIs.

• Auto Learn assigns any remaining DLCIs to the remaining stations configured for DLCI Auto Learn mode. As pointed out earlier, the DLCI assignments for stations in Auto Learn mode are performed in increasing numeric order. That is, the lowest reported DLCI number not assigned to a statically configured FRI station is assigned to the lowest numbered FRI station in Auto Learn mode. The next highest DLCI number is assigned to the next highest station number.

NoteEnable the DLCI Auto Learn mode for all ports using Same Port Backup. If the DLCI Auto Learn mode is not used, the backup FRI port must have DLCI numbers that match those of the primary link.




Example of DLCI Assignment

This table shows how DLCI numbers are assigned in ascending order according to available FRI stations:

DLCI Statistics The DLCI field on the first page of the FRI Stations Statistics screen indicates when a station is in Auto Learn mode and the number of the DLCI assigned to the station.

Configuration Guidelines

Do not use more than one Autolearn DLCI on a Frame Relay Interface port. During some link-outage conditions, a DLCI could be re-assigned to a different station number than the one to which it was assigned when the link first came up.

Network PVC DLCI No.

FRI Station Number

Configured DLCI Number

16 3 16

17 4 17

18 1 0

19 2 0

20 5 0

When This Appears... It Means...

Auto Learn The station is in Auto Learn mode

*xxxx This is the number of the DLCI assigned to the stationWhere:

• xxxx equals the network DLCI number• An asterisk (*) before a DLCI means the DLCI

number was obtained through the Auto Learn feature


Frame Relay Loopback Detection

Frame Relay Loopback Detection

Loopback Detection

When using Vanguard products the frame relay ports do not detect a condition in which transmit data is looped back to its received data. As a result, the Vanguard is unable to activate a backup link when the primary link is disrupted by an external loopback. The FRI port cannot detect the loopback condition when it receives a STATUS ENQ message. The FRI port automatically switches to bidirectional mode and responds with STATUS messages. The Vanguard does not realize the link is loopbacked when receiving STATUS messages in response to its own STATUS ENQ messages.

The Control Protocol Options in the FRI Port Parameters on page 11 includes a new option called DTE_ONLY. DTE_ONLY prevents the DTE from switching to bidirectional mode and causes incoming STATUS ENQ messages to be ignored. When the link does not receive a STATUS message in response to its ENQ message, it declares the link down and causes the backup to be activated.

NoteThe DTE_ONLY Option applies to Annex A and Annex D protocols.



Frame Relay Over ISDN


Introduction This section explains how Frame Relay traffic can be carried over ISDN connections.

NoteRefer to the Vanguard 6520/6560 ISDN Manual (Part Number T0103-05) and the Vanguard ISDN Manual (Part Number T0103-06) for information specific to ISDN as it applies to Frame Relay.

Feature Description

Vanguard products allow Frame Relay traffic to be carried over ISDN to provide functions such as those listed in this table:

NoteVanguard Frame Relay over ISDN operation varies depending on the Vanguard platform used.

Function Description

Bandwidth on Demand (BoD)

Enhanced BoD is possible when an ISDN link supplements the bandwidth of a Frame Relay network that is congested. (Refer to the “Congestion Control for Frame Relay Stations” section on page 43 for additional information.)An ISDN connection is established when the Frame Relay network experiences congestion. The same ISDN connection is automatically dropped when the Frame Relay network comes out of congestion.

NoteRefer to the Bandwidth Management Manual (Part Number T0108) for additional information.

Dial on Demand (DoD) An ISDN connection is made when there is traffic to be sent across a Frame Relay network that has connections made through a dial up line.The ISDN connection drops out when there is no traffic ready to be sent.

Link Backup Link Backup functionality is available when an ISDN link is used as an alternative to the normal Frame Relay/X.25 link. An ISDN connection is established when the Frame Relay/X.25 network link is down, and dropped when the primary link is up again. Same Port Backup functionality is used on lower port density products like the Vanguard 300, 305, 320, 34x. The Same Port Backup function is a variant of Link Backup. refer to the Bandwidth Management Basics Manual (Part Number T0108) and Vanguard ISDN Protocol Manual (Part Number T0103-06) for additional information on Link Backup.



Vanguard 6520/6560 Operation

The Vanguard 6520/6560 provides a virtual FRI port that is tied to a physical BRI channel. In this way, the virtual FRI port manages Frame Relay connections and traffic, while the physical BRI channel manages the ISDN interface and signalling.

The Switched Services Table is configured with the ISDN dial numbers associated with the FRI port. This configuration is performed in a similar fashion to that used for the Frame Relay over PRI interface feature currently available on the Vanguard 6560.

Operation on Other Vanguard Products

Vanguard products, other than the Vanguard 6520/6560, allow you to configure a physical FRI port on the ISDN BRI daughtercard. The Vanguard 310 series and the Vanguard 650 allow configuration of physical FRI ports, on the BRI interface, directly on the motherboard. In all cases though, the BRI ISDN interface record is configured with the port numbers that are associated with the D and two B channels.




Modes of Operation

Introduction The Frame Relay DTE Interface, over ISDN, is configured as either a virtual or physical Frame Relay port. Depending on what stations or virtual circuits are configured, the DTE interface provides two types of ISDN connectivity:

• Semi-Permanent• Dial-On-Demand (DoD)

Semi-Permanent Operation

Frame Relay virtual ports operate in semi-permanent mode when there is at least one PVC connection on the port. This can also be either a BYPASS or Annex-G station.

In this mode of operation, the ISDN call is established when any of these events take place:

• the Frame Relay node or virtual port is booted or enabled• the corresponding ISDN channel is booted or enabled• the port or the corresponding ISDN channel is enabled• the Frame Relay station is enabled

The ISDN connection is maintained as long as there is at least one active station on the Frame Relay virtual port. It is brought down only when:

• the Frame Relay virtual port is disabled• the corresponding ISDN channel is disabled• all the active stations are disabled

When there are no active PVCs on the Frame Relay virtual port, and if there is an Annex-G station which is not disabled, the Frame Relay interface switches to the Dial-On-Demand mode.

NoteThe Node Setup Timer, in the corresponding Switched Services Table entry, must be set to 0 to disable the timer and ensure that the ISDN connection is established when the Node is booted.

Dial-On-Demand Operation

Frame Relay virtual ports can only function in the Dial-on-Demand (DoD) mode when Annex-G stations are configured with SVCs. BYPASS stations can be configured but they should not have active PVCs.

In this operating mode, the Frame Relay virtual port establishes the ISDN connection when an SVC is established. SVC requests are held until the ISDN connection is established and the corresponding stations are detected UP or DOWN.

The ISDN call is terminated when all SVCs on the Frame Relay virtual port are cleared (depending on the parameters of the corresponding Switched Service Table entry). When any of the PVCs becomes active, the Frame Relay virtual port switches to semi-permanent operating mode.



Sample Vanguard 6520/6560 Network Configurations

Introduction This section describes configuration details for FR/ISDN functionality on the Vanguard 3xx/64xx platforms. This feature provides an ISDN connection for Frame Relay DTE port where, if a Frame Relay network PVC is inactive, the specified FRI port establishes a dial-up link over an ISDN service. The ISDN connection drops out when there is no traffic ready to be sent.

Parameters Any Frame Relay port between 100 to 254 can be a Frame Relay virtual port. These parameters are not applicable and do not appear for a Frame Relay virtual port:

• Connection Type• Clock Source• Clock Speed

All other parameters for the Frame Relay virtual port configuration and Frame Relay Station are the same as for a physical Frame Relay port.

Examples Figures 6 and 7 show Frame Relay interfaces initialized as virtual ports on the associated BRI B channels.

Figure 6. Semi-Permanent FRI over ISDN B-Channel

SVCAnnex-G Station and

LCON

PVCBYPASS Station and LCON

Port 104(Virtual Port on First B Channel)

PVCBYPASS Station and LCON

SVCAnnex-G Station and

LCON

ISDN FrameRelayFRI BRI

Vanguard6520/60

Vanguard 6520/6560

Port 25

FRI




Figure 7. Dial-on-Demand FRI over ISDN B-Channel

• The ports 104 and 105 are configured as FRI ports. • The first BRI B channel of port 25 is associated with the virtual port 104 by

setting the parameter Port Type to FRI and the Port Number to 104 (port 100 to 254 are virtual ports). The second BRI B channel of port 25 is associated with the virtual port 105.

• Switched Service Table entries are configured to correspond with ports 104 and 105 as Backup or Switched Service ports.

• The PVC Setup Table and Route Selection Table are configured for PVC connections to BYPASS stations of port 104 and SVC connections to Annex-G stations of ports 104 and 105. Here are the details for Port 104:- Port Number: 104- Port Type: FRI- Frame Sequence Counting: NORM- Packet Sequence Counting: NORM- Control Protocol Support: NONE- High Priority Station: 0- Maximum Voice Bandwidth bits per sec: 2048000- Segment Size When Voice Is Present: 64- Segment Size When Voice Is Not Present: Disable

When a Frame Relay virtual port is restarted (Node Boot or FRI Virtual Port Boot or BRI Channel Boot), it determines if any of its BYPASS stations are active.

• In Figure 6, port 104 initiates an ISDN connection on the associated BRI B channel and maintains this connection as long as any of its BYPASS stations are active or total SVC count for the port is not zero.

• In Figure 7, port 105 initiates an ISDN connection on the associated BRI B channel when there is an SVC request. The connection is dropped when the total SVC count for the port becomes zero (depending on the link hold timer value configured in the associated Switched Service Table entry).

BYPASSStation not Active

Port 105(Virtual Port on Second B

Channel)

SVCAnnex-G Station and X.25

SVCAnnex-G Station and X.25

ISDN FrameRelayFRI BRI

Vanguard6520/60

Vanguard 6520/6560

FRI

Port 25 X.25DTE

X.25DTE



Sample Vanguard 3xx/ 64xx Configurations

Description There are two methods of providing the dial number for Frame Relay over ISDN, through the Switch Services Table and through the ISDN Channel interface. The Semi-Permanent and DoD modes of operation are only available when the Switch Services Table method is used. Refer to the Vanguard ISDN Protocol Manual (Part Number T0103-06) for additional information.

Vanguard Configuration Example

Figure 8 shows how Frame Relay over ISDN could be used in Vanguard 3xx and Vanguard 64xx products. Configuring a PVC table entry in Node 100 from an FRI BYPASS station, sets the mode of operation to Semi-Permanent; otherwise the operation is Dial-on-Demand. Configuration of the nodes in this example, follows the figure.

Figure 8. Frame Relay over ISDN Configuration Example

NoteFigure 8 shows a dial number supplied by the Switch Services Table entry.

Configuring Node 100

Port Record ConfigurationThese Port Record parameters must be configured for Node 100:

ISDN

Frame Relay

X.25

FRI

Port 3

Port 1

BRI

FRI

Node 100

Vanguard 3xx/64xx

Port 4CTP

Port 5 Port 4

Port 3

Port 13

Port 6CTP

Node 200

Vanguard 6560

FRI

Port 2

FRIVirtual Port

100

Port Parameter Value

Number 1 Port Type:Connection Type:Link Address:

X25SIMPDTE

Number 2 Port Type:Connection Type:Clock Source:Clock Speed:Control Protocol Support:

FRISIMPINT64000NONE




BRI ISDN InterfacesThese BRI ISDN Interface parameters must be configured for Node 100:

Switched Service TableThese Switched Service parameters must be configured, for semi-permanent operation, on Node 100:


FRISIMPINT64000NONE

Number 5 Port Type: ETHLAN Cable Type: AUIPort MAC Address: Transmit Queue Limit: 50Carrier Sense Filter: 0Collision Detect Filter: 0*Bridge Link Number; 1*Router Interface Number: 1

ETHAUI08-00-3E-00-86-15500011

Port Parameter Value (continued)

Entry Parameter Value

Number 1 *D Channel Port:Switch Type:D Packet Traffic:*First B Channel Port:(First) Access Type:(First) Same Port Backup:(First) TEI:(First) Local Subscriber Directory Number: (First) Call Permission:(First) Channel Selection:(First) Outbound Dial Number #1:

15ESSDISABLE2CMDDISABLE1275551000OUT+INCEXCLUSIVEBlank


Number 1 *Destination Name:*Backup or Switched Service Port:Dial Sequence:

SS1FRI-25075555



FRI StationsThese FRI Station parameters must be configured on Node 100:

LAN Connection TableThese LAN Connection parameters must be configured on Node 100:

Route Selection TableThese Route Selection Table parameters must be configured on Node 100:

PVC Setup TableConfigure these Node 100 PVC Setup Table parameters when you want to operate in the semi-permanent mode operation. Do not configure this table if you want to use Dial-on-Demand.

Port/Station

Parameter Value

Port 2 Station 1

Station Number:*Station Type:

1BYPASS

Port 2 Station 2

Station Number: *Station Type:DLCI:Link Address:X.25 Options:

2Annex_G17DCECAUSE

Port 3 Station 1

*Station Type:DLCI:Link Address:X.25 Options:

Annex_G16DCECAUSE

Entry Value

Number 1 *LAN Forwarder Type:LAN Connection Type: *Router Interface Number:

ROUTPT_TO_PT5


Number 1 Address: #1 Destination: #1 Priority:

200FRI-2S21

Number 2 Address: #2 Destination:#2 Priority:

10094LCON2


Number 5 Source:Destination:

LCON-1FRI-2S1





Port Record ConfigurationThese Port Record parameters must be configured for Node 200:

NotePort 100 is being configured as a Virtual Port.

BRI ISDN InterfacesThese BRI ISDN Interface parameters must be configured for Node 200:



FRISIMPINT64000NONE

Number 4 Port Type:LAN Cable Type:Port MAC Address:Transmit Queue Limit:Carrier Sense Filter:Collision Detect Filter:*Bridge Link Number:*Router Interface Number:

ETHAUI08-00-3E-00-86-15500011

Number 13

Port Type:Switch Type:TEI:

BRI5ESS127

Number 100

Port Type:Frame Sequence Counting:Packet Sequence Counting:Control protocol Support:

FRINORMNORMNORM


Number 13

ISDN Channel Number:*Channel Type:Access Type:ISDN Call Acceptance:Local Subscriber Access:Local Subscriber Subaddress:Rate Adaptation:*Protocol Type:*Virtual Port Number:

1BSwitchedAddress Only5075555Blank64KFRI100



FRI StationsThese FRI Station parameters must be configured on Node 200:

Route Selection TableThese Route Selection Table parameters must be configured on Node 200:

PVC Setup TableThese PVC Setup Table parameters must be configured on Node 200:


Port 100 Station 1

Station Number: *Station Type:

1BYPASS

Port 100 Station 2

Station Number: *Station Type: DLCI: Link Address: X.25 Options:

2Annex_G17DTECAUSE

Port 3 Station 1

*Station Type:DLCI:Link Address:X.25 Options:

Annex_G16DTECAUSE


Number 1 Address:#1 Destination:#1 Priority:

100FRI-100S21

Number 2 Address: #2 Destination: #2 Priority:

20094|LCON2


Number 5 Source: LCON-1Destination: FRI-100S1

LCON-1FRI-100S1




Frame Relay Same Port Backup

Description This feature provides ISDN dial-backup service for Frame Relay DTE ports. With this feature, if a Frame Relay network PVC is inactive, the specified FRI port establishes an alternate Frame Relay connection over an ISDN service. This feature is supported only on Vanguard 300, 320 and 34x devices.

Initiating a Backup ISDN Call

A backup ISDN call is attempted (to a pre-configured number) when a full status message declaring the link as ‘Down’ is received. This also happens when individual status messages are received to indicate that all network PVCs are inactive.

Limitations Be aware of the following limitations:

• The Frame Relay network link must support LMI, Annex-D, or Annex-A link control protocols for the Same Port Backup feature to operate.

• If the dial backup Frame Relay port supports a different control protocol than that used in the primary Frame Relay network port, you must configure the LMI Auto-Learn feature.

• A secondary backup link checks to determine if the primary link has been re-established. While this check is made, the backup link connection is terminated.

Inactive Port An alternate Frame Relay connection is established when the PVC is inactive or unusable for the following reasons:

• Control protocol error condition, such as:- In-channel signalling link (DLCI 0, DLCI 1023) reliability errors- Signalling link protocol errors- Internal network problems

• The network reports that a link’s PVCs are inactive.• Priority Station Connection Loss (a DLCI or network PVC failure is

detected).

Priority Station Connection

A single station on a FRI port can be specified as a High Priority Station. This station is monitored by the FRI port for the status of the stations DLCI in network messages. All other stations on that port are disabled and re-routed to the backup ISDN link, when this high priority DLCI is inactive. All stations on the FRI port are re-enabled and full network communications resume when the backup link is activated.

If the ISDN backup call cannot be established, Frame Relay reverts back to the primary link which attempts to re-establish connection with the network. If this attempt fails, or the PVCs are reported as inactive, the backup link is attempted once again. The node cycles between the primary and backup link until a connection is established.



Configuring Same Port Backup

To implement Frame Relay Same Port Backup, you need to configure parameters in two records:

• Frame Relay Port Record• ISDN Configuration Record

These parameters are described in detail below.

Frame Relay Port Record Parameter

A new parameter has been placed under the Frame Relay Port Record: Priority Station. For details, refer to the FRI Port Parameters section.

ISDN Configuration Parameters

These are the parameters that must be configured to implement Frame Relay Same Port Backup:

NoteUnless otherwise indicated, you must perform an ISDN Channel Boot for changes to the following parameters to take effect.

*Channel Associated Port

Range: 0 to 3

Default: 2

Description: Identifies the access protocol that is to run over the ISDN B channel (in backup mode).

NoteChanges to this parameter require a Node Boot to take effect.

Same Port Backup

Range: ENABLE, DISABLE

Default: DISABLE

Description: Specifies Same Port Backup when this port is set to ENABLE.

Same Port Backup Option

Range: NONE, TIMEOUT, CALL

Default: NONE

Description: Specifies the switchback criteria for the backup ISDN line:• TIMEOUT: based on a user-configured timeout period• CALL: based on the status of the Backup ISDN call• NONE: No timeout




Same Port Backup Timeout

Range: 1 to 240

Default: 30

Description: Specifies the time (in minutes) when the ISDN backup line switches back.

Outbound Dial Number

Range: 0 to 60 alphanumeric characters

Default: (blank)

Description: Specifies the phone number to dial to establish an ISDN outbound call.

Call Retry Interval (sec)

Range: 5 to 3600

Default: 300

Description: Defines the time (in seconds) between ISDN dial attempts. To disable this parameters, set to zero (0).

Number of Call Retries

Range: 0 to 255

Default: 5

Description: Specifies the number of times the ISDN attempts calling at the Call Retry Interval. For unlimited call retries, set to 0 (zero).


Frame Relay SVCs

Frame Relay SVCs

Introduction This feature provides Switched Virtual Circuit (SVC) access to FRI port stations and is specific to the UNI (User to Network Interface) DTE FRI Port. Both PVC and SVC station circuits may co-exist on the same FRI port. All Frame Relay SVC calls entering the Frame Relay port are terminated at the port and there is no provision for call routing through the node. The FRI port function with individual FRI stations internally connected to another access port on the same node, or to a virtual circuit routed to another node.

Frame Relay SVCs terminate within the Frame Relay port and do not propagate further into the Vanguard node. That is, Frame Relay SVCs are not switched through or within the Vanguard. Consequently, Frame Relay SVC calls are not routed within the node, and routing tables or other call routing parameters do not have to be maintained within the node.

With this mode of operation, the FRI port is responsible for generating and terminating the setup procedures for SVCs. Characteristics for the SVCs are maintained by the FRI port. For FRI ports, each defined station corresponds to a network PVC and an assigned DLCI (Data Link Connection Identifier). In the case of auto learn, the DLCI value is assigned when LMI procedures determine a valid DLCI value to use for the station. Individual stations map either to a network PVC, or to a network SVC. In the case of SVC, the station is configured to be available for SVC usage and either initiates, or is assigned, a call according to SVC procedures occurring on the call control signalling channel of the Frame Relay link.

In addition to working with a station within the FRI port, the call control procedures also determine a DLCI value, usually assigned by the attached Frame Relay network equipment, to identify the Virtual Circuit. The characteristics of individual SVCs are determined by a combination of several factors:

• Certain parameters apply to all SVCs and are specified as blanket parameters configured for the FRI port (for example, the FRI port subscriber number assigned by the network service provider).

• Individual stations have their own values that can be tailored for individual SVCs (for example the CIR - Committed Information Rate - used on the virtual circuit).

• Some characteristics of the virtual circuit are negotiated at setup time by information elements included in the call related messages setting up the call.

SNMP Support Frame Relay SVCs do not currently support SNMP.



Frame Relay SVCs

Implementation Conformance

Conformance has two aspects:

• the procedures and protocols used in call establishment process• the standards set for the type of traffic conveyed by the Frame Relay link

The formal Frame Relay SVC specifications, ITU-T Q.922 and ITU-T Q.933. Q.922, specify the link level framing used for reliably exchanging call maintenance messages between attached equipment. This protocol is called LAPF and is similar to LAPD, the link procedure used in ISDN for the same purpose. Q.933 defines the protocol used for call maintenance messages. It is a subset of ISDN Q.931 and includes additional information elements specific to Frame Relay technology.

The Frame Relay Forum (FRF) took these Recommendations and produced an Implementation Agreement refered to as Frame Relay Forum Document 4 - SVC Implementation Agreement (FRF.4). This specifies the User to Network Interface (UNI), including the physical level. FRF.4 uses Q.922 procedures for the link level and a substantially reduced subset of Q.933 for call maintenance procedures. The SVC implementation in the FRI port conforms to the FRF.4 specification. This is the common mode of operation for Frame Relay running over serial ports. Some application traffic types are standardized within Frame Relay such as:

• IP traffic over RFC 1490• X.25 traffic over Annex G

In these cases, a local FRI port can connect to a remote device using the same protocol encapsulation. and interoperation between the local and remote is maintained.

Link Integrity Link integrity with PVCs is done with one of three protocols:

• LMI (Link Management Interface) as defined by NT, ST, DEC• Annex A as defined in ANSI T-616.1 (closely aligned to Annex D of ITU-T

Q.933)• Annex D as defined in ITU-T Q.933

Only one of these protocols can be in used at one time. Once a protocol is selected, it does not depend on there being any PVCs configured for the line. The line can be used exclusively for SVCs. A link failure is declared when there is a failure count of N392 (a configurable parameter for a FRI port) for the status enquiry response message (or status enquiry message in the case of bilateral Annex A/D). The FRI port supports full status report messages which are sent every N391 counts of the link verification message sent. In the case of no PVCs present, the FR network responds with a full status report listing no PVCs present, as expected.

When a link failure is declared (N392 count expiry), any PVCs are shut down; they neither send nor receive data. Internal steps are taken to indicate to the adjacent node that the connection is no longer available. Any SVCs present are not effected nor is the ability to establish further SVCs effected. The LMI procedures for PVC have the same effect on PVCs as it currently has, but it does not effect the operation of SVCs. Although an unlikely situation, it is possible for the LMI procedures to detect failure while the SVCs on a link are able to carry on with data transfers.


Frame Relay SVCs

The LAPF procedure is used on DLCI 0 for the purpose of reliably transferring call messages. In this case, the link integrity is also determined by the connections of the LAPF link station. If the LAPF link connection is not in place, because it did not establish a connection or because of a failure while in the data transfer state, then no SVC connections are maintained. With the LAPF link in a down state, existing SVCs are locally released, and new SVCs cannot be established.

Frame Relay SVC Addressing

It is necessary to refer to called and calling number or addresses within the FRI port. These are the address formats (numbering plans) allowed for FR SVC:

• E.164• X.121

These can be used with the FRI port as follows:

• Any entry for an address used in configuration of a station or port indicates the appropriate numbering plan. These are the valid formats:

xxxxxxxx

Exxxxxxxx

Xxxxxxxxx

Where:

xxxxxxxx represents the address of the station.

• E or X represents the numbering plan for the address with E=E.164 and X=X.121. E or X can be upper or lower case, must be the first character and, if absent, E is assumed.

• In some cases, it may be necessary to generate a message with a zero length address Information element. To do this, specifying an entry as a single character, either E or X, with no subsequent digits.

• The address is usually accompanied by a subaddress which conforms to the numbering plan of the main address. No prefix is needed or allowed.

FRI Port Parameters

An LAPF link connection on DLCI 0 must be maintained for SVCs to operate on an FRI port. This link connection needs the definition of link level procedure parameters. These parameters are new to the FRI port, but are similar to the parameters used in other LAP procedures found in the node, such as LAPB (X.25 layer 2) or LLC2 (Token Ring L2). This implementation follows Q.922. The system parameters for the LAPF procedure are listed below and documented for implementation as part of the Port record.

LAPF parameter N201 specifies the maximum frame size on the link. The implementation supports received frames up to 4096 bytes and transmit frames up to 2048 bytes.

In keeping with an access device’s memory requirements, LAPF window size should be set to 7. This should be adequate for the amount of signalling generally expected. This size does not limit in any way the number of calls per second the link or node can handle.

Other parameters are needed for SVC support on the link. These parameters are configured from the CTP and allow the system administrator to tailor the port’s operation or the stations’ requirements.


Frame Relay SVCs

Because SVCs and PVCs operate on the same link, there is a way of specifying where the SVCs reside in the DLCI number space (to prevent SVCs and PVCs inadvertently using the same DLCI number). For example, if an FRI station is configured to be an SVC that initiates a call, and it is configured to specify the DLCI in the SETUP message (note that DTE specifying the DLCI in the SETUP message is not supported in some FR network equipment), it needs to know what DLCI to specify. The value sent to the network in the SETUP message must be within the DLCI range defined in the attached network equipment. The FRI port does not accept incoming SETUP messages that specify a DLCI value below the configured starting SVC DLCI number.

Individual stations specify the DLCI value to be used for a PVC. For SVC operations, they specify or validate the SVC DLCI value to be used. The result is that the DLCI number space is a range of DLCI values that have a non-overlapping sub-range of values for PVC that occupy the lower part of the range and DLCI values for SVCs that occupy the upper part of the range. There may be a gap between the range values for DLCIs used for PVC and SVCs, as shown in Figure 9.

Figure 9. DLCI Ranges

The configuration of the port has a configured Subscriber Address used for the Calling Party Number Information Element. This parameter acts as a blanket value for all the stations using this port. The stations have individual subaddress parameters which are used in conjunction with the calls with which that the station supports. In most cases, any entity operating on the FR port uses this convenience since the Calling Party Number is usually the subscriber’s address on the attached FR network and does not vary from station to station. In many cases, especially where the FRI port is connected to a dedicated port on a FR network, this parameter value can be left blank, which causes the corresponding IE to be omitted or ignored from the outgoing/incoming SETUP message.

The port configuration also includes the system parameters used for Q.933 call control. These parameters are defined at the port level and apply to all stations making calls on the port.

DLCI range of values

Range of SVC DLCIs = Starting DLCI Number to 1007 (DLCI value option-ally defined in station

Range of PVC DLCIs = 16 to Starting SVC DLCI Number - 1 (DLCI values defined in stations

Starting SVC DLCI Number (defined in the port record)

16

1007



Frame Relay SVCs

SVC Operation

Introduction This section explains how the SVC related parameters are used in FRI port operation. There are two main areas of operation that are of concern for FRI SVCs:

• Outgoing calls together with IE selection and parameter value setting• Incoming calls together with Information Element (IE) processing and station

selection and assignment

Call Control Stations on a FRI port can be used for both initiating and receiving calls. In each case the parameters are configured differently.

The call control messages defined in Q.933 of most interest for this discussion are SETUP and CONNECT. Call control messages consist of Information Elements (IEs) that describe characteristics of the call and the resulting SVC. Mandatory IEs must be specified when making a call. The configured parameters of the station are used for creating the SETUP message IEs. For an incoming call, the call must be directed to a station with compatible characteristics as indicated in the incoming SETUP message IEs that the call originator supplied.

Be sure to configure the appropriate parameters to obtain proper operation. An obvious example is the use of called number and subaddress. If the FRI port is attached to a FR network, then leaving these parameters as blank means the corresponding IEs are not in the SETUP message and such a message fails to connect to any destination unless the network node is configured with some address for this situation.

Outgoing Call Processing

Introduction Outgoing calls are sent out an FRI port over the FR link attached to adjacent equipment, usually a FR network. Outgoing calls are initiated by sending a SETUP message on the signalling channel (DLCI 0) of the FR link. The SETUP message must have the proper format specified in the Q.931 standard as adopted by FRF.4.

Individual stations on the FRI port are the entities that make calls. To do so they must be configured with the station parameter Call Control set to AUTO or AUTD:

• AUTO indicates that the SVC duration is indefinite, being cleared only by a local boot command on the CTP or by DISCONNECT/RELEASE received from the remote.

• AUTD indicates that the SVC is DISCONNECTED after an idle timer interval expires. The idle interval is specified with the parameter AUTD Idle Timer Interval.

When the station initiates a call, the rules for forming the SETUP are straight forward. The message is made using the configured parameters of the station. The parameters correspond directly to an IE or part of an IE:

• If the parameter is non-blank (a value is entered), the corresponding IE is present in the SETUP message with the value set to the configured value.

• If the parameter is left blank (or set to NONE), the corresponding IE is not included in the SETUP message.



Frame Relay SVCs

These IEs are mandatory:

• Bearer Capability (automatically inserted for all calls)• Called Party Number

Optional IEs can be placed in the SETUP message by configuration of the station.

• Link Layer Core Parameters• Called Party Subaddress• Calling Party Number• Calling Party Subaddress• DLCI: A special case of the DLCI IE in the SETUP (see below)

DLCI IE FRF.4 does not permit a DLCI IE in the DTE originated SETUP message. This allows a DLCI IE to be inserted for unusual cases, such as when FRI ports are connected back to back or an FRI port is connected to other equipment that need the IE.

If the station is configured with the parameter Information Element Negotiation set to DLCI, the call includes a DLCI IE. This IE has a value equal to the lowest available DLCI at or above the value of the port parameter Starting SVC DLCI.

If the DLCI IE (of an in coming call) specifies an invalid DLCI, the response is RELEASE COMPLETE and no further processing takes place. To check if the specified DLCI is out of range, its value is compared to the port parameter Starting SVC DLCI and the call cleared if the DLCI is less than this number. If the Starting SVC DLCI value is inconsistent with the requirements of the attached equipment, you could experience difficulty in completing calls.

Link Layer Core Parameters (LLCP) IE

The Link Layer Core Parameters IE consists of a series of parameters specifying both inbound and outbound values. Inbound and outbound parameters are given the same value when they are set.

If the station is configured with the Information Element Negotiation parameter set to LLCP, the call includes a LLCP IE with these parameter values set:

• The parameter Maximum Frame Mode Information Field (FMIF) is always included and its value is set to the configured value in the port parameter Core Parameter Maximum Frame Size.

• The Throughput parameter is always included and its value is set to the configured value in the station parameter Committed Information Rate (CIR).

• The Minimum Acceptable Throughput parameter is always included and its value is set to 0.

• The Committed Burst Size parameter is always included and its value is set to the configured value in the station parameter Committed Burst Size (BC).

• The Excess Burst Size parameter is always included and its value is set to 0.


Frame Relay SVCs

Calling Party Number IE

The Calling Party Number IE is usually unnecessary when the FRI port is connected to an FR network. The network provides the IE when it forwards a message based on the subscribers number known by the network. Some networks may clear the call immediately if this IE is included. The Calling Party Number IE is included by the FRI port when the port parameter Subscriber Number has a non-blank value. The Number Plan ID is set to either E.164 or X.121 depending on the prefix (E or X) appended to the configured number. The Type of Number ID is always set to International.

Calling Party Subaddress IE

The Calling Party Subaddress IE is included when the station parameter Station Subaddress has a non-blank value. The Type of Subaddress ID is set to either NSAP. The Even/Odd Indicator is set to Even. The subaddress is formed from the configured entry as an IA5 character string prefixed with a AFI indicator specifying IA5 characters (x’50’).

Called Party Number IE

The Called Party Number IE is mandatory and is included by the FRI port when the station parameter Called Party Number has a non-blank value. The Number Plan ID is set to either E.164 or X.121 depending on the prefix (E or X) appended to the configured number. The Type of Number ID is always set to International.

Called Party Subaddress IE

The Calling Party Subaddress IE is optional and is included when the station parameter Called Party Subaddress has a non-blank value. The Type of Subaddress ID is set to NSAP. The Even/Odd Indicator is set to Even. The subaddress is formed from the configured entry as an IA5 character string prefixed with a AFI indicator specifying IA5 characters (x’50’).

How the Called Party Subaddress is formed is based on the needs of interworking with another FRI port across an intervening FR network. The configurable parameters at both ends ensure that a calling station of a given type can connect to a specific target station which it knows to be its proper destination.



Frame Relay SVCs

Incoming Call Processing

Introduction Incoming calls arrive on an FRI port over the FR link attached to some adjacent equipment, usually an FR network. Incoming call processing must have a policy or algorithm defined to make sure the call is handled properly. That is, the incoming SETUP message is checked for correct form and then its contents (Information Elements, IEs) are used to select a station assigned to the call. Checking the proper format of the SETUP message is a matter of enforcing the specifications of the Q.931 standard as adopted by FRF.4. To select the station to assign to the call is a matter of rules defined specifically by FRI port on a Vanguard product.

The check for conformance to the standards, the call is given a preliminary check to make sure the mandatory information elements are present and have correct format. If this preliminary check fails, the SETUP is responded to with a RELEASE COMPLETE message.

These IEs are mandatory:

• Bearer Capability• DLCI• Link Layer Core Parameters• Calling Party Number

Optional IEs in the SETUP are also checked. However, these are ignored if present.

• Called Party Subaddress (but is checked against local station configuration, if present)

• Calling Party Subaddress• Low Layer Compatibility• User to User

The remaining optional IE that can be present in the SETUP is Called Party Subaddress. This IE is further processed to select a station for the SVC as described below.

DLCI IE First, the specified DLCI IE is checked. The DLCI IE may be marked preferred or exclusive but is always taken as exclusive since FRF.4 specifies exclusive to be the required setting. If the DLCI IE specifies a DLCI out of valid range or a DLCI in use, the response is RELEASE COMPLETE without further processing. To check whether the specified DLCI is out of range, its value is compared to the port parameter Starting SVC DLCI and the call cleared if the DLCI is less than this number. If the Starting SVC DLCI configured value is inconsistent with the requirements of the attached equipment, there may be difficulty in completing calls on a given port.

If these checks pass, the DLCI is reserved for the call and is later assigned to the SVC if the call SETUP goes to successful completion.


Frame Relay SVCs

The next step is to check individual stations to select one that satisfies the requirements of the call. The stations are scanned in order of increasing station number and a candidate station must have all these basic characteristics:

• The Station Circuit Type parameter is configured as SVC.• The Call Control parameter is configured as RECV.• It must be in an idle state (not currently involved in a call).• It must not be in a station disabled state (as controlled by the CTP).• The station is connected to an adjacent entity to accept data. (For example, a

Bypass Station must be connected to a WAN adapter LCON via an entry in the PVC Connection table and the LCON must be enabled before the Bypass Station can accept a call.)

Called Party Subaddress IE

If the SETUP message has a called party subaddress IE present, this IE is used to specify the station in the connection. This is done by requiring that the received IE matches the value configured for the Station Subaddress parameter. This IE is composed of these three fields:

• the type of subaddress indicator (User Defined or NSAP)• even/odd indicator• and subaddress digit/character string

A match requires that the incoming type of address indicator is NSAP. The even/odd indicator is ignored. The subaddress string must be IA5 character coded string prefixed with the corresponding NSAP AFI (x’50’) and must match the station configured subaddress.

When a Vanguard FRI port station generates a SETUP, and there is a configured Called Party Subaddress, the called party subaddress IE is formatted according to the requirements of a match described above. This ensures interoperability according to these rules when FRI stations call each other over an FR network. This is done automatically though the operator must fill in the matching subaddresses.

If, in the incoming SETUP message, the Called Party Subaddress IE is absent, then the first station configured with a blank Called Party Subaddress is the station used for the call (assuming other requirements in this section are satisfied).

If, in the incoming setup message, the Called Party Subaddress IE is present, then its format must be NSAP with AFI prefix followed by an IA5 coded number string. This number string is converted to an actual number and the first station configured with a Called Party Subaddress equal to that number is the station used for the call. (This assumes that other requirements in this section are satisfied.)

Link Layer Core Parameters IE

The final processing of the SETUP involved the Link Layer Core Parameters (LLCP) IE. To simplify the process, this rule is adopted:

If the station parameter Information Element Negotiation does not have the value LLCP, incoming LLCP IE parameter values are accepted and the station is set to operate with the requested values.

The two most important parameters are throughput (committed information rate) and committed burst size. The remaining parameters are copied for statistics display purposes but do not alter the station performance.



Frame Relay SVCs

This method (LLCP not specified in Information Element Negotiation) is the simplest way to operate and satisfies most requirements. Individual parameters in the LLCP IE are optional and can be absent. When these parameters are absent from the IE, the values in the station configuration are used in default. Also, when the CONNECT response is sent back when the call is successfully completed, the LLCP IE in the CONNECT contains most of the parameters (Minimum Throughput is absent).

If the Information Element Negotiation parameter is set to LLCP, the incoming IE values are also used to select a station that satisfies the requested values and sets the values as follows:

• The Frame Mode Information Field (FMIF) parameter specifies the maximum desired frame size. If the incoming FMIF value is present and specifies a value larger than the port parameter Core Parameter Maximum Frame (FMIF) Size, the call is cleared. If the indicated value is less than or equal to the configured size, the station value is set to the lower of the two values and processing continues.

• The Throughput parameter specifies the CIR desired for the SVC. If the incoming Throughput value is present and specifies a value larger than the Committed Information Rate (CIR), the call is cleared. If the indicated value is less than or equal to the configured size, the station is set to operate with the lower of the two values and processing continues.

• The Minimum Acceptable Throughput parameter is not used. It is ignored on input and not present in the LLCP IE of the CONNECT message if the call is established.

• If the incoming Committed Burst Size value is present, and specifies a value larger than the station parameter Committed Burst Size (Bc), the call is cleared. If value is less than or equal to the configured size, the station is set to operate with the lower of the two values and processing continues.

• The Excess Burst Size (Be) parameter is not used. It is ignored on input. The LLCP IE of the CONNECT message if the call is established contains the value of the incoming SETUP IE.

Examples

Description This section contains examples for:

• LLCP Computation• FRI PVCs/SVCs• WAN Adapter and FRI Port Details• WAN Adapter FRI Port Details


Frame Relay SVCs

LLCP Computation Example

In this example (see Figure 10), the configuration of the node port and station are shown. Messages flowing between the call originator and destination are shown with arrowed lines. The arrowed lines have a set of numbers showing the LLCP values as they appear in the message.

Each LLCP parameter has two values since they can both be present.

• The first value corresponds with the value for the outgoing parameter value.• The second value represents the value for the incoming parameter.

An entry such as CIR=16000,12000 means the LLCP CIR outgoing is 16000 and incoming is 12000.

NoteThe term outbound means leaving the port toward the line and the term inbound means arriving from the line at the port.

In this example, the originating station asks for a CIR of 16000 but allows a MinCIR of 12000. The destination station is configured to operate with a CIR of 12000. Since the destination station is allowed to negotiate the LLCP, it accepts the call with a CONNECT message specifying a CIR of 12000.

Figure 10. LLCP Computation Example

FRI Configuration:===========CIR = 16000minCIR = 12000Bc = 12000Be = 12000

llcp:==========FMIF = 21000CIR = 16000, 16000minCIR = 12000, 12000Bc = 12000, 12000Be = 12000, 12000

llcp:==========FMIF = 21000CIR = 16000, 16000minCIR = 12000, 12000Bc = 12000, 12000Be = 12000, 12000

CONNECT

llcp==========

FMIF = 21000CIR = 12000, 12000Bc = 12000, 12000Be = 12000, 12000

llcp==========FMIF = 21000CIR = 12000, 12000Bc = 12000, 12000Be = 12000, 12000

CONNECT

FRI Configuration:===========CIR = 12000minCIR = 12000Bc = 12000Be = 12000Information Element Neg. = LLCP

SETUPSETUP

Frame Relay



Frame Relay SVCs

CSK for Link Restart

Under certain circumstances, a peer node may restart an FRI SVC signalling link after it has experienced a service effecting condition or other circumstances. An example of such an occurrence is when one node, or a port on a node, is booted. Frequently, the service effecting condition is short lived. A port boot can be accomplished in a few seconds. On the node where the boot occurred, all the calls for FR SVCs are removed and the link is restarted. The restarting is signalled by issuing a link level SABME frame. If a local node is unaware of the service effecting condition, it treats the incoming SABME as a reset of the LAPF procedure and the calls handled by that link are unaffected (according to FRF4 procedures). At the end of the service effecting condition, the local node perceives that the call is in place but the booted node usually has no calls in place. This locks out call resources and can require manual intervention to correct. Usually, you need to boot the node or port that still has calls in place.

To bring peer and local calls to a common state after a service effecting condition, a CSK is added which allows the local FRI LAPF to treat a SABME received in data transfer state as if it were a DISC frame. This causes the link to be declared down, and any calls on the link to be cleared. Any following SABME frames received are treated in the normal way. They are used to bring the link up.

The CSK is:

C2JK93TDJLUTS8N7FX7F

This CSK also has another effect on the variation to standard procedures. When specified, the CSK allows the FMIF (largest frame to be handled by a call) to be specified as low as 1 octet. This is important in voice application, where small FMIF values may be specified in the Link Layer Core Parameters Information Element to filter calls to specific stations with a correspondingly configured FMIF value. Without the CSK, the minimum FMIF allowed is 262 octets.

FRI PVC/SVCs Example

Terminating the SVC process within the FRI port has certain advantages. A major one is that existing Vanguard protocols and modules that interwork with the FRI SVCs need not be concerned with any FRI SVC awareness. All internal protocol stack connections remain the same. Therefore, support for existing protocols (for example X.25 [Annex G], FRA, IP via WAN Adapter [WA]) is maintained. Other characteristics of the FRI port are also preserved. This includes Dial-on-Demand and Dial-on-Start-up. Because these features relate to establishing the physical level (this includes ISDN B channel establishment), the phrase Setup-on-Demand refers to establishing the Frame Relay SVC. This avoids confusion with the Dial-on-Demand function which can occur on the same port at about the same time.

Figure 11 shows a Vanguard node supporting Frame Relay SVCs on an FRI port. Both SVC and PVC stations are present on the FRI port to show how their functionality can be combined. In this example, the FRI port and its stations are configured so there are:

• Bypass stations, two of which are Frame Relay SVC and one Frame Relay PVC

• Annex G stations, one each of Frame Relay SVC and PVC


Frame Relay SVCs

Figure 11. FRI SVCs/PVCs

Other ports and interfaces are defined which use the FRI stations in this manner:

• (1) One router interface (via the WA--WAN Adapter) carries RFC 1490 IP traffic and uses an FRI Bypass station configured as an FR SVC. The interconnection between the WAN Adapter and the FRI station is defined in the PVC Table. The FRI station is configured to be a Frame Relay SVC and operates with the attached equipment as an SVC.

• (2) A second router interface (via the WAN Adapter) carries IP traffic over an FRI Annex G station. The Annex G station supports multiple X.25 SVCs (two are shown in the figure) and the Annex G station uses an Frame Relay PVC.

• (3) A PPP port connects to an FRI Bypass station. This connection is established by the PVC Table. The FRI station is a PVC to its attached equipment.

• (4) One FRA PVC station connects to an FRI Bypass station. This connection is established by the PVC Table. In this case, the FRI station appears as an SVC to its attached equipment.

• (5) One X.25 SVC channel connects to an FRI Annex G channel (X.25 level 3 to X.25 level 3). This connection is established by X.25 call procedures. In this case, the FRI station appears as an SVC to its attached equipment.

LAN

WA

FRI port

PPP

FRA

X.25

FR PVC

FR SVC

Connections established by PVC Table entries

Connections established by X.25 SVC calls

FRL2

BO

Annex G

5 6

18

16

19

20

17

Bypass

Bypass

Bypass

Annex G

1

2

3

4



Frame Relay SVCs

NoteThe FR SVC is a separate entity and definition from the X.25 SVC. Multiple X.25 SVCs (and PVCs) can be supported by a single FR SVC.

• (6) A second X.25 SVC channel connects to a different FRI Annex G channel. This connection is established by X.25 call procedures. In this case, the FRI station appears as a PVC to its attached equipment. Again, multiple X.25 SVCs (and PVCs) can be carried within a single Frame Relay PVC.

The above figure shows a mix of both PVCs and SVCs within some of the configurations (for example connections 1 and 4). In the case of connection 1, a PVC Table entry is used to interconnect the WAN Adapter LCON-1 interface, which corresponds to an IP router interface, to station #1 on the FRI port.

WAN Adapter and FRI Port Details Example

This connection is static and defined in the PVC Table. Figure 12 shows only the WAN Adapter and FRI port detail for this case.

Figure 12. WAN Adapter/ FRI Port Interconnection Detail

FRI port

FR PVC

FR SVC



FRL2

BOP

Annex G

Bypass

This interconnection defined by PVC Table entry:Source Destination

LCON-1 FRI- 1S1

Port #1Station #1

This FR SVC setup by station #1 configuration

Station #2

LAN

WA

1

LCON-1

18

16

19

20

17

Annex G

Bypass

Bypass


Frame Relay SVCs

In this example, Station #1 is configured as an FR SVC. Therefore on the FR link it must establish a circuit using call maintenance procedures before passing data. In this instance, it is already setup with a remote destination; the SVC is in place as implied by the dotted line. SVCs (and PVCs) are multiplexed onto the same FR line by a separate DLCI. Station #1 uses DLCI 18 while station #2, which is a PVC, uses DLCI 16.

Usually, on an FR link, PVC assignment is done with a contiguous span of permanently assigned DLCI values. In the Vanguard product, DLCI assignment is configured on a station basis and so DLCIs can be assigned in any contiguous or non-contiguous manner. In addition DLCI assignments can be autolearned (“Frame Relay Auto Learn and Remote DLCI Configuration” on page 57 and “Auto Learn DLCI Assignment” on page 61). For SVCs, the DLCI assignment is done on an First come, first serve basis. The actual DLCI value used is normally assigned by the FR network, not the DTE (FRI port). In the node FRI station configuration of Figure 12, Station #1 was first to make a setup and so was assigned the lowest available SVC DLCI=18. If it had been the last of the three stations to setup, it would have been assigned DLCI=20.

The establishment of SVCs is bi-directional. The FRI port can be configured to initiate a setup of an SVC or it can be configured to accept the setup from the attached network equipment. For incoming calls from attached equipment, the indication of the DLCI value to use is always part of the setup message.



Frame Relay SVCs

WAN Adapter FRI Port Details Example

Station #3 on the FRI port, shown in Figure 13, is configured as an FR SVC, similar to Station #1. It too must follow the SVC procedures in establishing connections to pass data. In this case the SVC is in place and the FR link DLCI used for this SVC is 19.

Figure 13. Example 3 WAN Adapter/FRI Port Interconnection Details

FRI Station #3 is a Bypass station and is connected to the corresponding Bypass station on the FRA port (Station #1). It does not matter if the FRI station is configured as PVC or SVC. The connection between the FRA and FRI stations is established with an entry in the PVC Table. The SVC characteristics of the FRI station are not visible to the adjacent entity in the node. This preserves the current definitions of functionality for the node and reinforces the model where FR SVCs are not switched within the node.

One important rule about FRI Bypass Stations operating as SVCs, is that they do not initiate a call, nor accept a call unless the adjacent station is prepared to pass data. In this example, Station FRA-3S1 was disabled or the Port FRA-3 determined that the attached DTE was down (using its Control Protocol), the corresponding FRI Station, FRI-1S3, would not be allowed to establish an SVC circuit on its Frame Relay line.

FRI port

FR PVC

FR SVC



FRL2

BOP

Annex G

This interconnection defined by PVC Table entry:Source Destination

FRA-3S1 FRI-1S3

Port #1Station #1

Station #2

FRA

Port #3

Station #3

Station #1 (Bypass)

18

16

19

20

17

5 6

This FR SVC setup by station #3 configuration

Bypass

Bypass

Bypass

Annex G

4


Frame Relay SVCs

The configurational aspects of the other stations in Figure 11 should be based on the above discussion, It is important that the X.25 SVCs and PVCs operating on an Annex G station in the FRI port do not interact with the nature of the FR circuit type. Figure 11 tries to show this by having one X.25 channel connected to an Annex G station operating as an SVC (connection 5) and the other Annex G stations operating as a PVC (connection 6). These connections are defined by the X.25 routing table and PVC Table entries for X.25 virtual circuits.



Frame Relay SVCs

Sample Configuration Example

Configuration Example

Figure 14 is an example configuration of Frame Relay SVCs. It shows a network connection diagram where two asynchronous terminals, at different sites, are connected to host ports via Frame Relay SVC network connections.

Figure 14. Frame Relay SVC Configuration Example

Here two async terminals pass data over FR Annex-G stations. The stations at the terminal endpoints are configured to connect to the host computer via Frame Relay SVC connections when there is data to send, and to drop the connection upon a configured idle time-out. Both terminal endpoints are configured to be the call originators; async traffic passed over the Frame Relay network through Annex-G protocol encapsulation.

The following sections detail the configuration of the nodes in Figure 14.

Configuring Remote Node 100

Port Record ConfigurationThese are the Port Record parameter values for Node 100:

Vanguard

Vanguard

Vanguard Frame Relay

Node 100==========Port Address: 9055071201Called Party Subaddress: 1

Node 200==========Port Address: 9055071202Called Party Subaddress: 2

Node 300==========Port Address: 9055071200Station Subaddresses:Station 1:1Station 2:2

Host

Parameter Value

Port Number 1

Port Type FRI

Connection Type SIMP

Clock Source EXT (network provides the clock)


Frame Relay SVCs

Station 1 ConfigurationThese are the Station Record parameter values for Node 100:

Clock Speed 64000

Frame Sequence Counting NORM

Packet Sequence Counting NORM

Control Protocol Support NONE (no PVC control protocol)

High Priority Station 0

Starting SVC DLCI Number 500

Subscriber Number 9055071201

Setup Timer (T303) 4

Disconnect Timer (T305) 30

Release Timer (T308) 3

Call Proceeding Timer (T310) 30

Parameter Value (continued)

Parameter Value

Station Number 1

*Station Type ANNEX_G

Station Circuit Type SVC (FR SVC)

Call Control AUTD (autocall when data present)

AUTD Idle timer interval 15 (disconnect FR SVC after 15 seconds of idle)

Information Element Negotiation NONE (use network default values)

Station Subaddress <blank> (not needed or used)

Called Party Number E9055071200 (node 300 address)

Called Party Subaddress 1

Committed Information Rate (CIR) 16000

Committed Burst Size (BC) 16000

End-to-End Transit Delay 50

Congestion Control Mode NORMAL

Link Address DTE

*Number of PVC Channels 0

*Starting PVC Channel Number 1

*Number of SVC Channels 1 (only one terminal)

*Starting SVC Channel Number 1

Initial Frame SABM



Frame Relay SVCs

NoteThe station parameter T4 Poll Timer is set to zero (0). This disabled the RR poll of the Annex-G station. This is necessary since this configuration example is set up for an idle disconnect of the Frame Relay SVC call. If this Annex-G parameter were configured to something other than zero, RR polling would persist and the Frame Relay SVC station would see this poll as data. The SVC circuit would therefore never be cleared (as a result of idle time). Another option would be to set the T4 poll timer to a value greater than the idle disconnect time-out. However, the result would be the establishment of the Frame Relay SVC each time the RR Poll and response are exchanged over an otherwise idle line.

Configuring Remote Node 200


T1 Transmission Retry Timer (1/10 sec) 30

T4 Poll Timer 0 (do not use default, see note below)

N2 Transmission Tries 10

K Frame Window 7

W Packet Window 7

P Packet Size 128

Data Queue Upper Threshold 5

Data Queue Lower Threshold 0

Restart Timer 180

Reset Timer 180

Call Timer 200

Clear Timer 180

X.25 Options NONE

Restricted Connection Destination (blank)

CUG Membership --,--,--,--,--,--,--,--

Billing Records OFF


Parameter Value

Port Number 1

Port Type FRI


Clock Source EXT

Clock Speed 64000




Frame Relay SVCs

Station 1 ConfigurationThese are the Station Record parameter values for Node 200:

Control Protocol Support NONE


Starting SVC DLCI Number 500







Parameter Value

Station number 1


Station Circuit Type SVC

Call Control AUTD

AUTD Idle timer interval 15

Information Element Negotiation NONE

Station Subaddress <blank>

Called Party Number E9055071200

Called Party Subaddress 2





Link Address DTE



*Number of SVC Channels 1


Initial Frame SABM


T4 Poll Timer 0


K Frame Window 7



Frame Relay SVCs



W Packet Window 7

P Packet Size 128



Restart Timer 180

Reset Timer 180

Call Timer 200

Clear Timer 180

X.25 Options NONE


CUG Membership --,--,--,--,--,--,--,--

Billing Records OFF


Parameter Value

Port Number 1

Port Type FRI


Clock Source EXT

Clock Speed 64000



Control Protocol Support NONE


Starting SVC DLCI Number 500 (it must match node 100 and 200 values)







Frame Relay SVCs

Station 1 ConfigurationThese are Station Record parameter values for Node 300, Station 1:

Parameter Value

Station Number 1



Call Control RECV

AUTD Idle timer interval 0 (not used)


Station Subaddress 1 (node 100 uses this station)

Called Party Number (blank)

Called Party Subaddress (blank)





Link Address DCE (compliments node 100 station DTE)





Initial Frame SABM


T4 Poll Timer 0


K Frame Window 7

W Packet Window 7

P Packet Size 128



Restart Timer 180

Reset Timer 180

Call Timer 200

Clear Timer 180

X.25 Options NONE



Frame Relay SVCs

Station 2 ConfigurationThese are the Station Record parameter values for Node 300, Station 2:


CUG Membership --,--,--,--,--,--,--,--

Billing Records OFF


Parameter Value

Station Number 2



Call Control RECV

AUTD Idle timer interval 0


Station Subaddress 2 (Node 200 uses this station)

Called Party Number (blank)

Called Party Subaddress (blank)





Link Address DCE





Initial Frame SABM


T4 Poll Timer 0


K Frame Window 7

W Packet Window 7

P Packet Size 128



Restart Timer 180

Reset Timer 180


Frame Relay SVCs

Call Timer 200

Clear Timer 180

X.25 Options NONE


CUG Membership --,--,--,--,--,--,--,--

Billing Records OFF




Frame Relay SVCs

SVC Connections On-Demand

Introduction Frame Relay SVC connections can be configured so that they come up on-demand to route incoming calls to remote destinations. This feature is supported through the interaction of Frame Relay and Network Services.

This section explains how to implement this feature.

Keep These in Mind...

Keep in mind these factors when using SVCs and Network Services for on-demand calls:

Interworking with FRI over ISDNWhen using this feature with ISDN, make sure the B-Channel is brought up as a virtual leased line.

Annex G OnlyThe on-demand calling feature using Network Services is available for Annex G stations only. For information about configuring Bypass stations for on-demand calls, refer to the “Outgoing Call Processing” section on page 81.

On-Demand Connections Using SVCs

Network Services enables FR SVC Annex G stations to be brought up on-demand, when there is an X.25 call to be put through. The elements of the process are:

• Route Selection Table• FRI Annex G SVC Station• Address Mapping• X.25 Call Forwarding• FR SVC Clear

These elements are explained below.

Route Selection Table

The Route Selection Table specifies that calls be forwarded over FR SVCs. The port number is specified but not the station. The station is determined dynamically based on these two factors:

• the called address of the incoming X.25 call• available stations

NoteWhen the entry is saved, a warning message may be displayed. Ignore this message.

To route a call over a PVC station, specify the full name, such as FRI-1S1 (FRI port 1, Station 1).

FRI Annex G SVC Station

You must configure the FRI Annex G SVC station for on-demand calls. The key parameters, which must be configured, are:

Call ControlThis parameter determines the calling behavior of the SVC Station. Set it to CNORM so that calls are made through Network Services. It is possible to have a combination of CNORM, RECV and AUTO stations. For more information regarding this parameter refer to the parameter Call Control on page 22.


Frame Relay SVCs

Information Element NegotiationThis parameter allows the listing of parameters to be used. If the network supports this function, set the parameter to TPIE (Traffic Priority Information Element). Otherwise, set it to <blank>. For more information regarding this parameter refer to the parameter Call Information Element Negotiation on page 24.

NoteIf TPIE is set, a voice call routed onto an SVC station causes the node to request high priority using TPIE. When a data call (from LCON for example) is routed onto a SVC station, the node requests normal priority. Therefore, the very first X.25 call that initiates the FRI SVC connection decides the priority of the SVC.

Called Party Number and Called Part SubaddressLeave these parameters <blank>. If you enter values other than <blank>, the station tries to initiate a call.

Address Mapping For FRI SVCs, the destination FRI SVC address is picked up from the Address Mapping Table located under the Network Services Configuration Menu.

The called X.25 address in the call packet is used to search the table to find the corresponding FRI address. The FRI address could be E.164 or X.121. The source address needs to be X.121 and the destination address needs to be X.121 or E.164 depending upon the numbering system used by the network.

NoteAddress Mapping is available only for Frame Relay SVCs.

X.25 Call Forwarding

FRI Annex G SVC stations are treated as a pool for forwarding outgoing X.25 calls. The X.25 Reachability Table contains information about the FRI SVC station that is connected and which X.25 destinations are reachable. See Figure 15. The X.25 Reachability Table is located under the Network Services Stats menu.

Before the call is forwarded, the Reachability Table is checked to see if an FRI SVC is station already connected.

• If a station is connected, the call is forwarded on that station (if the number of data and voice SVCs configured in the FRI station allow the call).

• If no FRI SVC station is connected (through which the X.25 called address is reachable), a new one is initiated.

The call is buffered until the SVC comes up, after which the X.25 call is forwarded. If the call is accepted, the X.25 Reachability Table has a new entry for the new FRI SVC and indicates the X.25 called address as being reachable.



Frame Relay SVCs

Figure 15. X.25 Reachability Table

FR SVC Clear Almost immediately after the last the X.25 call on an SVC clears, the SVC itself is disconnected. After the SVC disconnects, no more calls can be forwarded until it becomes idle again.

Backup using FRI SVCs

FRI Annex G SVCs can be used as backup routes for X.25 calls. This is done by configuring the Route Selection Table and giving the destination a priority of 0 (zero).

The link backup using FRI SVCs in the Switched Services Table is not supported. Therefore, you cannot bring the SVC down when the primary link comes up.

Node: Address: Date: Time: X25 Switched Connection Table

----------------------------------------------------------------------This table provides a list of X25 destinations that are connected usingswitched links. This table is used for dynamically routing X25 calls

over switched links, instead of bringing up new ones every time.Currently, only destinations connected through FRI SVCs are supported.

----------------------------------------------------------------------

Remote X25 Destination = 303 Physical Link = FRI-1s1 Current Link State = Level 3 UP Number of X25 Calls = 1 Link Priority = 1

Press any key to continue ( ESC to exit ) ...


Booting FRI Stations

Booting FRI Stations

Introduction Booting updates operational parameters of a node using the FRI parameters stored in configuration memory (CMEM).

Booting an FRI Port

A Port Boot clears all calls on that port. Any changes to operational parameters do not occur until a boot is completed. To boot the FRI Port:

Booting an FRI Station

A Station Boot clears all calls on that station. Any changes to operational parameters do not occur until a boot is completed. To boot the FRI Station:

NoteIf you change the number of SVCs or PVCs, you receive a message similar to one of the following:

When one of these messages is received, you must perform a node boot to activate the configuration change for the port or station.

Step Action

1 Select Boot from the Main menu, then select Port.

2 At the prompt, select the port number you want to boot.

Step Action

1 Select Boot from the Main menu, then select FRI Station.

2 At the prompt, select the port number and then the station number you want to boot.

ERROR EXPLANATION

CANNOT BOOT PORT #p Topology or # of stations has changed# of SVCs has changed# of PVCs has changed

CANNOT BOOT STATION #s # of SVCs has changed# of PVCs has changedStart SVC has changedStart PVC has changed



Examining FRI Configuration Records


What Is It? Once you have defined the FRI parameters and stored them in Configuration Memory, you can verify them with the Examine command.

Examining FRI Port and FRI Records

To examine the Port Record:

Example Figure 16 shows a display similar to the one that appears on the screen.

Figure 16. Port Record Examination, Port 1

Step Action

1 Select Examine from the Main menu.

2 Select Port from the Examine menu.

3 At the prompt, enter the number of the port you want to examine.

Port Record ExaminationPort Number: 1/1Node Address: Date: Time: Port Record Examination: Port 1 Page: 1 of 1

[1] *Port Type: FRI[1] Connection Type: SIMP[1] Clock Source: EXT[1] Frame Sequence Counting: NORM[1] Packet Sequence Counting: NORM[1] Control Protocol Support: LMI[1] Control Protocol Options: NONE[1] Control Protocol Role: DTE[1] Discard Control Options: NONE[1] High priority Station: 0[1] Maximum Voice Bandwidth bits per sec: 2048000[1] Segment Size When Voice Is Present: 64[1] Segment Size When Voice Is Not Present: Disabled[1] T391/nT1 Poll Timer: 10[1] T392/nT2 Verification Timer: 15[1] N391/nN1 Full Status Polling Cycle: 5[1] Starting SVC DLCI Number: 500[1] Subscriber Number: [1] Core parameter Maximum Frame (FMIF) Size: 2100[1] Setup Timer (T303): 4[1]Disconnect Timer (T305): 30[1] Release Timer (T308): 4[1] Call Proceeding Timer (T310): 30

Press any key to continue (ESC to exit)...



Follow These Steps To examine the FRI Port Stations:

Example Figure 17 shows a sample of the Examine screen for FRI Port Stations.

Figure 17. FRI Station Examination, Port 1, Station 1

Step Action


2 Select FRI Stations from the Examine menu.

3 At the prompt, enter the numbers of the port and the station you want to examine.

Port Record Examination: Port 1 Page: 1 of 1Port Number: 1/1Station Number: 1/1

Node: Address: Date Time: FRI Station Examination: Port 1, Station 1 Page: 1 of 2[1] *Station Type: BYPASS[1] Station Circuit Type: SVC[1] Call Control: NORM[1] Information Element Negotiation: LLCP[1] Station Subaddress:[1] Called Party Number: 5551212[1] Called Party Subaddress:[1] DLCI: 16[1] Committed Information Rate (CIR): 16000[1] Committed Burst Size (BC): 16000[1] End-to-End Transit Delay: 50[1] Congestion control Mode: NORMAL[1] Voice Congestion Control Mode: Disabled[1] Link Address: DTE[1] Number of PVC Channels: 0[1] Starting PVC Channel Number: 1[1] Number of SVC Channels: 16[1] Starting SVC Channel Number: 1[1] Initial Frame: SABM[1] T1 Transmission Retry Timer (1/10 sec): 80[1] T4 Poll Timer: 90[1] N2 Transmission Tries: 10[1] K Frame Window: 7[1] W Packet Window: 7Press any key to continue (ESC to exit)...




Port/Station/Channel Control Command

Introduction This section describes commands for enabling/disabling FRI ports and FRI stations.

Follow These Steps...

To Enable/Disable a selected FRI Port or FRI Station:

Enabling the FRI Port or FRI Station

Enabling the FRI port or FRI station brings the FRI port or FRI station back online after it has been disabled from the CTP.

To enable the FRI port or station:

Disabling the FRI Port or FRI Station

Disabling the FRI Port or FRI Station brings it offline and clears all calls on that port or station without deleting its configuration record.

To disable the FRI Port or FRI Station:

Step Action

1 Select Port/Station Channel Control from the Main menu.

2 From here you can choose one of the following:• Enable FRI Port• Disable FRI Port• Enable FRI Station• Disable FRI Station.

Step Action

1 Select Enable FRI Port or Enable FRI Station from the Port/Station Channel Control menu.

2 At the prompt, enter the selected port number.

Step Action

1 Select Disable FRI Port or Disable FRI Station from the Port/Station Channel Control menu.



FRI Status/Statistics


Introduction This section describes the Vanguard statistics used in FRI. Other Vanguard statistics are described in the Vanguard Basis Manual. You can use these reports to monitor FRI operation:

• “Detailed Port Statistics” on page 110• “Detailed FRI Station Statistics” on page 117• “Detailed Link Statistics” on page 127




Detailed Port Statistics

What You See Detailed Port Statistics provide status reports about various operations of the node.

Follow These Steps To view the Detailed FRI Port Statistics:

Example Figures 18 through 21 show an example of the Detailed FRI Port Statistics.

Figure 18. Detailed FRI Port Statistics - Page 1 of 5

Step Action

1 Select Status/Statistics from the Main menu.

2 Select Detailed Port Statistics from the Status/Statistics menu.

3 At the prompt, enter the number of the selected port. See Figure 18.

Node: Address: Date: Time:Detailed FRI Port Statistics: Port 1 Page: 1 of 5

Port Speed:0 Operating Control Protocol: Auto-learn Protocol Role: DTEPort Status: Down SP-Backup: Not Configured Priority Station: 0

Data Summary: Last Statistics Reset:IN OUT IN OUT

Characters: 4726 8050 Characters/sec: 100 170Frames: 546 513 Frame/sec: 11 10Av Fr size: 8 15 Port Util.: 1% 2%

Physical/Frame Relay SummaryCRC Errors: 0 Overrun Errors: 0Non-Octet Aligned: 0Frame Length Errors 0 Underrun Errors: 1Unknown DLCI count: 0 Last Unknown DLCI: 0

Interface Summary: EIA-232-D DCE INPUT OUTPUTDTR RTS MB P14 DSR DCD RI CTS

State: Connected (SIMPLE) L L L L H H L H







UNI Segmentation DisabledNumber of Lost Synchronizations: 0

Splitting ratio : 0%Total Segments Lost : 0Maximum Contiguous Segments Lost : 0Voice Bandwidth Allocated on Port : 0Frame Segmenter Synchronization Lost : 0

LMI Link Statistics:IN OUT IN OUT

LIV Status Enq: 0 0 LIV Status: 0 0Full Status Enq: 0 0 Full Status: 0 0Async Updates: 0 0

T391/nT1 Timeouts: 0T392/nT2 Timeouts: 0 Seq Num Mismatch 0PVC Mgm Link State: down

Press any key to continue (ESC to exit) ...


Number of Operating Stations: 2






Screen Terms for Detailed FRI Port Statistics

This table describes the terms used in the Detailed FRI Port Statistics screen.


Stn# DLCI Adm A Aj N Cg Stn# DLCI Adm A Aj N Cg Stn# DLCIAdm A Aj N Cg========================================================================1 0016 1 0 1 0 0 2 0017 1 0 0 0 0


Term Description

Port Speed Specifies the message transmission speed in bps.

Port Status Specifies the current port status.• Up: The port is operational.• Down: The port is not operational due to some error

condition having occurred.• Disabled: The port has been administratively disabled

via the CTP.

Operating Control Protocol

Specifies the control protocols used, for example, ANNEX_A, ANNEX_D, LMI, and AUTO-learn.

SP-Backup Specifies whether a High Priority Station is configured.• Not Configured: No High Priority Stations are

configured.• Configured: The current configuration includes a

High Priority Station.



Priority Station Identifies the High Priority Station. If the PVC management protocol detects a problem with this station, the Same Port Backup mechanism triggers the FRI port backup.

Data Summary • Characters: Indicates the number of characters received or transmitted since last boot or statistics reset.

• Frames: Indicates the number of frames received or transmitted since last boot or statistics reset.

• Av Fr size: Indicates the average number of bytes contained in the frame.

• Characters/sec: Indicates the average number of characters received or transmitted per second.

• Frames/sec: Indicates the average number of frames received or transmitted per second.

• Port Util: Indicates the factor determined by comparison of volume (characters per second) of data and clock rate for a specific port.

Physical/Frame-Relay Summary

• CRC Errors: Indicates the number of errors detected by Cyclic Redundancy Check (CRC) since last node boot or reset of statistics. Indicates that a frame received contains one or more corrupted bits.

• Non-Octet Aligned: Indicates an invalid frame that is not divisible by eight.

• Frame Length Errors: Indicates the number of frames received with length less than five characters.

• Unknown DLCI count: Indicates the number of frames received with DLCI for which no station is configured.

• Overrun Errors: Indicates that an input buffer overflowed and characters were discarded.

• Underrun Errors: Indicates the number of times a buffer underrun occurred since last node boot or reset of statistics.

• Last Unknown DLCI: Indicates the last unknown DLCI received in a frame.

Term (continued) Description




Interface Summary State: Indicates the current state of the EIA signals. For a complete listing of EIA states, refer to the Vanguard Configuration Basics Manual (Part Number T0113).Input:

• DTR (Data Terminal Ready)• RTS (Request To Send)• MB (Make Busy)• P14

NoteThese signals are monitored by the Control Terminal Port.Output:

• DSR (Data Set Ready)• DCD (Data Carrier Detect)• RI (Ring Indicator)• CTS (Clear To Send)

NoteThese signals are generated by the Vanguard port.

UNI Segmentation There are three possibilities for this statistic:Synchronized or Unsynchronized which indicates the current local segmentation synchronization state. This also indicates that segmentation is enabled.Disabled which indicates that local segmentation is disabled.

Number of Lost Synchronizations

Indicates the number of lost synchronizations since the last port boot.

Splitting Ratio: Indicates the number of frames segmented divided by the total number of frames.

Total Segments Lost: Indicates the number of frame segments that have been lost (not received by the local port) in the network.

Maximum Contiguous Segments Lost:

Indicates the maximum number of contiguous segments lost (not received by the local port) in the network.

Voice Bandwidth Allocated on Port:

The bandwidth allocated to voice circuits on the stations. This is not the bandwidth being used.Type of voice call:

• 8 kbps with fax disabled or 4.8 kbps fax: 10,800 allocated bandwidth

• 8 kbps with 9.6 kbps fax:11,733 allocated bandwidth• 16 kbps:18,800 allocated bandwidth

Frame Segmenter Synchronization Lost:

A count of the number of times the local port frame segmenter went out of sync with the remote frame segmenter.




LMI Link Statistics This part of the statistics screen identifies the status of several LMI Link conditions. The IN and OUT values can be correlated to Received and Sent.

• LIV Status Enq: Indicates the number of LIV (Link Integrity Verification) STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset.

• Full Status Enq: Indicates the number of Full STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset. Full messages request a full status report on the status of all PVCs.

• LIV Status: Indicates the number of LIV STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset.

• Full Status: Indicates the number of Full STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset.

• Async Updates: Indicates the number of STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset. Async updates are out of sequence messages that report the status of all PCVs.

• T391/nT1 Timeouts: Indicates the number of times that the T391 timer has expired for the ANNEX_A or ANNEX_D PVC management protocol (nT1 expiry when using the LMI protocol).


• Seq Num Mismatch: Indicates the number of times a received sequence number fails to match the one expected.

• PVC Mgm State: Identifies the current status of the PVC management link.

Number of Operating Stations

Identifies the number of operating stations.

Stn# Station Number. This corresponds to the number that you assign to this station on the FRI port.

DLCI Indentifies the DLCI value that the station is operating on.

Adm Identifies the stations administrative status. Two values may appear:

• 0 - the station is disabled.• 1 - the station is enabled.





Figure 22 displays page 5 of the detailed port statistics.


A This identifies the A-bit condition seen by the station. Two values may appear:

• 0 - The A-bit is inactive on the DLCI• 1 - The A-bit is active on the DLCI.

Aj This identifies the status of the adjacent station. Two values may appear:

• 0 - The adjacent station is inactive.• 1 - The adjacent station is active.

N This indicates that status of the N-bit acknowledgment. Two values may appear:

• 0 - The station is not waiting for an N-bit.• 1 - The station is waiting to receive the N-bit

acknowledgment.

Cg This indicates the congestion state and identifies whether the station is in flow control. Two values may appear:

• 0 - The station is not in flow control.• 1 - The station has either sent or received LMI flow

control.


Press any key to continue (ESC-exit, 'N'-next sect, 'S'-skip to station) ...

Node: 340_QUAD Address: 200 Date: 8-MAR-2002 Time: 11:05:53 Detailed FRI Port Statistics: Port 3 Page: 5 of 5 Monitor control signals on port 01 for 1 change (type: SW56K) on 22-APR-1998

Number of Input Output changes NIS BPV DL C+ C- RS LL CL IDL CLK State Time ========= ================ ================ ============ ======== 1 L H H H H H H H H H Connected 03:33:19 2 H H H H H H H H H H Connected 03:33:20 3 H L H H H H H H H H Connected 03:33:23 4 H H H H H H H H H H Connected 03:33:24



Detailed FRI Station Statistics

Viewing FRI Station Statistics

To view the FRI Station Statistics:

Screen Examples The screens shown in Figures 23, 24, 25, and 26 display information about the selected node. Figures 27 and 28 show the screens for the Bypass mode.

Figure 23. Detailed FRI Station Statistics - Page 1 of 4

Step Action


2 Select FRI Station Statistics from the Status/Statistics menu.

NoteSelect Reset FRI Station Stats to reset all station statistics to zero.

3 Select Detailed FRI Station Stats from the FRI Station Statistics menu.

4 At the prompt, enter the number of the selected port.

Node: Address: Date: Time:

Detailed FRI station statistics. Port 1, Station 1 Page: 1 of 4

Port Number: 1 Station Type: Annex GStation Number: 1 Station Status: Link SetupDLCI: 16 Station State: ControlledMax Info Rate: 32000

Configured CIR: 16000 Congestion DetectedAllowed Info. Rate: 63480 Implicit: 0 Explicit: 0 Voice: 0

Call Summary: Data link utilization maximum:SVC PVC Avg. bytes/sec: 0 / 0% CIR

Maximum: 0 0 Date, Time: 12-MAR-1997, 11:13:49Current: 0 0 Monitoring Interval (sec): 1920 Data Summary: Last Statistics Reset: 13-MAR-1997 09:59:26

IN OUT IN OUTCharacters: 141456 459732 Characters/sec:32 104Packets: 23578 8841 Packets/sec: 5 2Frames: 43965 40583 Frames/sec: 10 9

Utilization: 0% 1%Number of Packets Queued: 0 Time in congestion (sec): 0


LMI Flow Control: OFF







Detailed FRI station statistics. Port 1, Station 1 Page: 2 of 4Frame Summary:

IN OUT IN OUTInfo 32472 32471 RR 11548 8154RNR 0 0 REJ 0 0SABM 2 12 DISC 0 0DM 0 0 UA 2 2

FRMR 0 0

Packet Summary:IN OUT IN OUT

Data 23612 8854 Receiver Ready 8854 23612Receiver Not Ready 0 0 Reject Packet 0 0Call Request 0 1 Call Accept 1 0Clear Request 0 0 Clear Confirm 0 0Interrupt Request 0 0 Interrupt Conf. 0 0Reset Request 0 1 Reset Confirm 1 0Restart Request 3 3 Restart Confirm 0 0Frame Segmenter State: Disabled



Detailed FRI station statistics. Port 1, Station 1 Page: 3 of 4Last inbound LCN: 0Inbound processing status: Processed OK, call passed to ROUT

Last Inbound Call, before processing:Called Address:Calling Address:Facilities:CUD:

Last Inbound Call, after processing:Called Address:Calling Address:Facilities:CUD:





Figure 27. Detailed FRI Station Statistics (BYPASS)- Page 1 of 2


Detailed FRI station statistics. Port 1, Station 1 Page: 4 of 4

Last Outbound LCN: 0Outbound processing status: Processed OK, call transmitted

Last Outbound Call, before processing:Called Address: 1010070Calling Address: 1020060Facilities:CUD:

Last Outbound Call, after processing:Called Address: 1010070Calling Address: 1020060Facilities:CUD:


Node: Address: Date: Time:Detailed FRI Station Statistics: Port 1, Station 2 Page: 1 of 2

Port Number: 1 Station Type: BypassStation Number: 1 Station Status: InactiveDLCI: 17 Station State: UnusedMax Info Rate: 32000 LMI Flow Control: OFFCongestion Detected: 0 PVC State: DisconnectedTime in Congestion (sec): 0FRI Summary: Data Link Utilization Maximum:

IN OUT Avg. bytes/sec: 0 0% CIRFECN: 0 0 Date, Time: N/A, N/ABECN: 0 0 Monitoring Interval (sec): 0DE: 0 0

Data Summary:Last Statistics Reset:IN OUT IN OUT

Characters: 0 0 Characters/sec: 0 0Frames: 0 0 Frames/sec: 0 0Frames Discard: 0 0 DE Frm Discard: 0 0Packets Queued: 0 0 Utilization: 0% 0%

Number of Packets Queued: 0 Time in Congestion (sec): 0





Figure 28. Detailed FRI Station Statistics (BYPASS) - Page 2 of 2

Screen Terms for Detailed FRI Station/Statistics

This table describes the terms used in the Detailed FRI Station Statistics screens.


Frame Segmenter State: Disabled

End-to-End Segmentation State: SynchronizedEnd-to-End Segmentation Type:Number of Lost End-To-End Synchronizations: 0


Term Description

Port Number Designates a specific port in the network diagram.

Station Number Identifies the station being configured.

Station Type Annex G and Bypass are the only station types that support the FRI option.

DLCI Data Link Connection Identifier is the unique identifier for the station on the FRI port and must match the DLCI configured on the Frame Relay networking node.

Station Status Determines the station status (Active, Link Setup, and so on).

Station State • Uncontrolled: Indicates that the station is uncontrolled.• Controlled: Indicates that the station rate is controlled.• Unused: Indicates that the station is disabled.

NoteStation state is in Controlled state when either of the following is true:

• Congestion Control Mode is NORM or LIMIT and the network is congested

• Voice Congestion Control is enabled• Congestion Control Mode is CONG• MIR is enabled (>0)

LMI Flow Control Indicates whether LMI Flow Control is On or Off.



Configured CIR Committed Information Rate.

Max Info Rate Maximum Information Rate.

Congestion Detected

• Implicit: Indicates the number of times that Implicit Congestion procedures have been invoked.

• Explicit: Indicates the number of times that Explicit Congestion procedures have been invoked.

• Voice: Indicates the number of times voice congestion procedures have been invoked.

Allowed Info. Rate Rate at which data is accepted by network.

FRI Summary (Bypass only)

Determines the input and output of FECN, BECN, and DE.

Call Summary Maximum• PVC: Indicates the maximum number of channels

permanently assigned between network resources.• SVC: Indicates the maximum number of SVCs active in

the network.Current

• PVC: Indicates the current number of permanent channels in use.

• SVC: Indicates the current number of SVCs in use.

Data Link Utilization Maximum

The data volume sent by a Frame Relay station in a given amount of time.

• Ave. bytes/sec: Indicates the average transmission rate in bytes per second. This is also calculated as a percentage of the CIR (Committed Information Rate).

• Date, Time: Indicates the date and time at which the Data Link Utilization is calculated.

• Monitoring Interval (sec): Indicates the period (in multiples of 64 seconds) over which Data Link Utilization values are collected and averaged. A Monitoring Interval of 5 equals: (5 X 64 sec) = 320 seconds.





Data Summary • Characters: Indicates the number of characters received or transmitted since last node boot or statistics reset.

• Packets: Indicates the number of packets received or transmitted since last node boot or statistics reset.

• Frames: Indicates the number of frames received or transmitted since last node boot or statistics reset.

• Characters/sec: Identifies the average number of characters received or transmitted per second.

• Packets/sec: Identifies the average number of packets received or transmitted per second.

• Frames/sec: Identifies the average number of frames received or transmitted per second.

• Utilization: Indicates the quantity of user bytes sent down the link expressed as a percentage of the maximum number of bytes that could have been sent.

• Time in congestion (sec): Indicates the total that the FRI Station has spent in a Congested mode of operation.

• Frames Discard (BYPASS only): indicates the number of frames that have been discarded by this station.

• Packets Queued (BYPASS only): Indicates the current number of frames in the transmission queue for this station.

• DE Frm Discard (BYPASS only): indicates the number of frames, marked with the DE-bit, that have been discarded by this station. To see this value in the statistics screen, you must have set the Discard Control Options parameter, in the Port Record, to DE BIT.

Number of Packets Queued

Current number of packets buffered since last node boot or statistics reset.




Frame Summary • Info: Identifies the number of Data frames transmitted or received since last node boot or statistics reset.

• RNR (Receiver Not Ready): Identifies a request, by the DTE or the network, to stop data flow on a particular virtual circuit.

• SABM (Set Asynchronous Balanced Mode): Identifies a message sent on initial power-up of a node to initialize the link and allow communication.

• DM (Disconnected Mode): Identifies a message issued by the network to request a SABM from the DTE.

• RR (Receiver Ready): Clears the RNR request.• REJ (Reject): Requests retransmission of a frame, due to

detection of a transmission or frame sequence error.• DISC (Disconnect): Ensures that both ends of a

connection are in the phase before link initialization. The DISC message is issued by the DTE or DCE.

• UA (Unnumbered Acknowledgment): Response to an SABM.

• FRMR (Frame Reject): Transmitted by the receiver to the sender, the FRMR frame is sent to report an error condition.





Packet Summary • Data: Indicates a packet containing user information.• Receiver Not Ready (RNR): Identifies a request, by the

DTE or the network, to stop data flow on a particular virtual circuit.

• Call Request: Initiates establishment a virtual circuit with a remote DTE by sending a Call Request packet.

• Clear Request: Initiates call clearing. This command is issued by the DTE or the DCE.

• Interrupt Request: Initiates a procedure that allows one octet of information to be sent to a remote DTE to which the normal flow of packets is temporarily blocked.

• Reset Request: Starts a data transfer on a PVC, which may be necessary if a PVC has been down but is now available. Under certain conditions this procedure can also be used by an SVC.

• Restart Request: Clears all SVCs and resets all PVCs governed by the DTE that issues the request. This can be issued by either the DTE or the DCE.

• Receiver Ready: Identifies a flow control packet used to clear the RNR request.

• Reject Packet: Initiates retransmission from the network of unacknowledged DATA packets. This option is available only during the data transfer phase and is issued by the DTE.

• Call Accept: Indicate that a call was accepted. This causes the calling DTE to receive a Call Connected packet.

• Clear Confirm: Acknowledges receipt of a Clear Indication packet. This is sent by the calling DTE to the called DTE.

• Interrupt Confirm: Acknowledges the INTERRUPT and is always generated by the DTE.

• Reset Confirm: Identifies when a reset procedure is complete.

• Restart Confirm: Identifies that a RESTART REQUEST has been accepted by the DCE.

Frame Segmenter State

Indicates whether Frame Segmentation is enabled or disabled.




Last Inbound LCN Specifies the logical channel number of the last inbound packet.

Inbound Processing Status

Outcome of last incoming call received on this station.

Last Inbound Call, before processing

• Called Address: Identifies the called address before address translation was performed.

• Calling Address: Identifies the address from which a call originated.

• Facilities: Specifies information used from the Call Request Packet.

• CUD: Identifies end user data or routing information specific to the network. Bytes 1 to 4 are reserved for protocol

Last Inbound Call, after processing

• Called Address: Identifies the called address after address translation was performed.

• Calling Address: Identifies the address from which call originated.


• CUD: Identifies end user data or routing information specific to the network. The first 4 bytes are reserved for protocol.

Last Outbound LCN

Specifies the logical channel number of the last outbound packet.

Outbound Processing Status

Identifies the outcome of last call request sent on this station.

Last Outbound Call, Before Processing

• Called Address: Identifies the called address before address translation was performed.



• CUD: Identifies end user data or routing information specific to the network. Bytes 1 to 4 are reserved for protocol

Last Outbound Call, After Processing

• Called Address: Identifies the called address after address translation was performed.



• CUD: Identifies end user data or routing information specific to the network. Bytes 1 to 4 are reserved for protocol.





Voice Header Insertion Statistics

Figure 29 displays the Voice Header Insertion statistics. These statistics are displayed when the Station Type is BYPASS, End-to-End segmentation is Enabled and End-to-End Segmentation Type is FRF.12.

Figure 29. Voice Header Insertion Statistics

End-to-End Segmentation State

Indicates the state of the segmentation station. Three states exist:

• Synchronized or Unsynchronized which indicate the current synchronization state of the station. Either of these conditions indicate that segmentation is enabled.

• Disabled indicates that segmentation is disabled in this station.

End-to-End Segmentation Type

Indicates is the station is implementing FRF.12 or VanguardMS End-to-End segmentation.

Number of Lost End-to-End Synchronizations

Indicates the number of lost synchronizations since the last port boot.

Voice Header Insertion

Indicates whether the Voice Header is inserted or not. It is visible only when the Station Type is BYPASS, End-to-End segmentation is Enabled and End-to-End Segmentation Type is FRF.12.



End-to-End Segmentation State: SynchronizedEnd-to-End Segmentation Type: FRF.12Number of Lost End-To-End Synchronizations: 0Voice Header Insertion Enabled




Detailed Link Statistics

Follow These Steps To view Detailed Link Statistics:

Screen Example This is an example of the Detailed Link Statistics screen.

Figure 30. Detailed Link Statistics

Screen Terms This table describes the terms used in the Detailed Link Statistics screen.

Step Action


2 Select Detailed Link Statistics. See Figure 30.

Node: Address: Date: Time:Detailed Link Statistics Page: 1 of 1

Type State CRC Link Data frames Utilizationentity subtype state speed date/time errors down in/out in/out====== ======= ===== ===== ========= ======= ==== ============ =============p1 FRI up 63480 0 0 79902 1%

Port 74540 2%

p1s1 FRI up 0 10-JAN-1997 0 2 73210 0%Station 04:16:35 67793 1%



Press any key to continue (ESC to exit)

Term Description

Type • Entity: Specifies the port number and the station number.• Subtype: Identifies either an FRI port or FRI station.

State The current status of the operational link specified under the port or station.

• Up: Identifies if the port or station is operational.• Down: Identifies if the port or station is not operational.• Disabled: Identifies if the port or station is disabled.




Speed Identifies the message transmission speed in bps.

Date/Time Identifies when the condition was present.

CRC Errors

Specifies the number of errors detected since the last node boot or statistics reset.

Link Down

Specifies the number of time the link is inoperative. Occurs when the number of attempts to connect (as set during configuration) is exceeded.

Data Frames

Specifies the number of frames received since last node boot or statistics reset.

Utilization Indicates the quantity of user bytes sent down the link expressed as a percentage of the maximum number of bytes that could have been sent.

Term Description (continued)



CCS Statistics

Introduction This section describes the Vanguard statistics used in conjunction with FRI SVCs. Additional statistics can be found in the Vanguard Configuration Basics Manual (Part Number T0113).

You can use these reports to monitor FRI SVC operation:

“Level 2 Statistics” on page 129

“Level 2 Detailed Statistics” on page 130

“CC Call Summary” on page 132

Statistics related to FRI SVC calls are controlled and monitored by the Common Channel Signalling Module (CCS).

Level 2 Statistics

What you See Level 2 Statistics provide summary status reports about port operations on the node.


To view the Level 2 Statistics:

Example Figure 31 shows an example of the CCS Level 2 Statistics.

Figure 31. CCS Level 2 Statistics

Step Action


2 Select CCS Statistics from the Status/Statistics menu.

3 Select Level 2 Statistics from the CCS Statistics menu.


CCS Level 2 Statistics Page: 1 of 1

Link Link/State Link Data Framesdslid Port State Date/Time Down in/out=== ==== ===== ======== ==== ===========

1 1 up dd-mm-yy 1 5hh:mm:ss 34





Screen Terms for CCS Level 2 Statistics

This table describes the terms used in the CCS Level 2 Statistics screen.

Level 2 Detailed Statistics

What you See Level 2 Detailed Statistics provide status reports about port operations on the node.


To view the Level 2 Detailed Statistics:

Term Description

dslid This number is an internal number that indicates the FRI port is registered with the CCS module and can run FR SVC protocol.

Port Number Specifies a specific port in the network diagram.

Link State Indicates the state of the LAPF procedures for the FR SVC signalling channel. If this link state is down, the port cannot have FR SVC calls in place. up: the link is up and operation of FR SVCs is allowed down: the link is down and FR SVC cannot be established

Link State Date/Time Specifies the time the current LAPF link state was established. Link Down Specifies the number of times the LAPF link has gone down.

Data Frames in/out Specifies the number of frames that have been transmitted and received by the LAPF procedure.

Step Action



3 Select Level 2 Detailed Statistics from the CCS Statistics menu.

4 At the prompt, specify the port number for which detailed Level 2 Statistics are required.



Example Figure 32 shows an example of the CCS Level 2 Statistics.

Figure 32. CCS Level 2 Statistics

Screen Terms for CCS Level 2 Statistics

This table describes the terms used in the CCS Level 2 Detailed Statistics screen.


CCS Level 2 Detailed Statistics Page: 1 of 1Port: 1 Last Statistics Reset: dd-mm-yy hh:mm:ss

Frame SummaryIN OUT IN OUT

Info 533 517 RR 44 37RNR 0 0 REJ 0 0SABME 1 1 DISC 0 0DM 0 0 UA 1 1

FRMR 0 0

Link Stat: 7 (multiple frame established)


Term Description


Last Statistics Reset Indicates the date and time the last time the statistics were reset.

Info IN/OUT Specifies the number of I frames received and transmitted by this LAPF procedure.

RR IN/OUT Specifies the number of RR frames received and transmitted by this LAPF procedure.

RNR IN/OUT Specifies the number of RNR frames received and transmitted by this LAPF procedure.

REJ IN/OUT Specifies the number of REJ frames received and transmitted by this LAPF procedure.

SABME IN/OUT Specifies the number of SABME frames received and transmitted by this LAPF procedure.




CC Call Summary

What You See CC Call Summary provides status reports about Frame Relay SVC calls that are currently active in the node. The report is generated by the CCS Call Control Module. CC Call Summary only reports currently active calls.


To view the CC Call Summary:

DISC IN/OUT Specifies the number of DISC frames received and transmitted by this LAPF procedure.

DM IN/OUT Specifies the number of DM frames received and transmitted by this LAPF procedure.

FRMR IN/OUT Specifies the number of FRMR frames received and transmitted by this LAPF procedure.

Link State This gives the current link state for the LAPF procedure. The link state is identified with its Q.922 number and description:

• 4 (TEI assigned)• 5 (Awaiting establishment)• 6 (Awaiting release)• 7 (Multiple frame established)• 8 (Timer recovery)


Step Action



3 Select CC Call Summary from the CCS Statistics menu.



Example Figure 33 shows an example of the CC Call Summary.

Figure 33. CC Call Summary

Screen Terms for CC Call Summary

This table describes the terms used in the CC Call Summary screen.


CC Call Summary Page: 1 of 1

Port/ Connect DLCI/ CIR/Stn date/time Dir Address C.ref Bc TP==== =========== === =============== ===== ======= ==FRI-1 dd-mm-yy in 5551212 23 16000 3S1 hh:mm:ss 0001 16000


Term Description

Port This is the FRI port number for the call being reported.

Stn This is the FRI station number for the call being reported.

Connect date/time Specifies the date and time the call became active.

Dir Specifies the direction of the call:• in: the call entered the FRI station from the

attached FR network• out: the call was sent to the attached network by

the FRI station.




Configure CCS L2 Trace Buffer

Description You can specify what is being traced by the CCS Trace function, and how it is displayed, by using Configure CCS L2 Trace Parameter. This is located in the Stats of CCS Resources menu (under the Status/Statistics menu).

Procedure Perform these steps to configure the CCS L2 Trace parameters:

Address This is the address that was used in the call. The displayed address depends on the direction of the call:

• in: the address is the calling address of the remote caller.

• out: the address is the called address used by the station.

The address is displayed in ASCII format. The Type of Number is prefixed to the displayed number with the following meaning:

• U: unknown type of number • E: type of number is E.164 • X: type of number is X.121

DLCI Specifies the DLCI assigned to the call.

C.Ref Specifies the call reference information element associated with this call. The value is displayed in hex format (digits are 0-9 and A-F). In this display, the high order bit (direction flag) is always set to 0.

CIR Specifies the value of the Throughput assigned to the call. The number is displayed in Decimal format and represents the value for the outbound direction.

Bc Specifies the value of the Burst Excess assigned to the call. The number is displayed in Decimal format and rep-resents the value for the outbound direction.

TP Specifies the value of Traffic Priority assigned to the call. The number is displayed in hex format and is related to the outbound priority.

Term Description

Step Action


2 Select Stats of CCS Resources from the Status/Statistics menu.

3 Select Configure CCS L2 Trace Parameter from the menu.



You can see the results of the Trace by using these selections, described in these sections:

• Examine CCS L2 Trace Buffer, on page 136• View CCS L2 Trace, on page 140

Frame Parsing When you set the parameter Frame parsing depth, you determine how the trace screen appears:

• When set to 0 (zero), the traced messages are displayed, without any detail, as shown in Figure 34.

• When set to 1, the traced message are displayed, with added detail, similar to the information shown in Figure 35.

Figure 34. Trace Messages When Parsing Set to 0

4 This prompt appears:Enter port number to monitor:This is the port number for which the Trace records frames. If you enter 0 (zero), the trace records for all ports.Enter the port number followed by <cr>.

5 This prompt appears:Frame parsing depth:This controls how the Trace parses the frame:

• 0: the frame is not parsed, only a raw printout is generated.• 1: the frame is parsed and there is a printout.

NoteFor more information, refer to the Frame Parsing section below.

Enter the value (0 or 1) followed by <cr>.

Step Action (continued)

number: 3637 size : 55 time : Date: Time:port : 3 dir : outPDU : 00 01 04 06 08 02 00 02 05 04 03 88 A0 CF 19 02 41 80 48 19 09 10 34 10PDU : B4 0A 30 10 30 90 0B 30 10 30 90 0D 0F 50 0F D0 0E 0F 50 0F D0 6C 05 11

PDU : 80 31 30 30 70 01 91

number: 3638 size : 55 time : Date: Time:port : 4 dir : inPDU : 00 01 04 06 08 02 00 02 05 04 03 88 A0 CF 19 02 41 80 48 19 09 10 34 10PDU : B4 0A 30 10 30 90 0B 30 10 30 90 0D 0F 50 0F D0 0E 0F 50 0F D0 6C 05 11PDU : 80 31 30 30 70 01 91




Examine Level 2 Trace Buffer

Introduction The Examine Level 2 Trace Buffer reports on the link activity that occurred on the LAPF data link. The data is captured in the background while the node is operating. When the Examine Level 2 Trace Buffer is running, the capture of data is halted until you exit this function.

Procedure To view the Level 2 Trace Buffer Statistics, perform these steps:

Step Action



3 Select Examine CSS L2 Trace Buffer from the menu.

4 The Examine CCS L2 Trace Buffer screen appears. Figure 35 is an example of what such a screen can look like.Trace buffer messages are displayed in groups of four. After each group of four messages, this prompt appears: Enter selection (<cr>: continue, r: reverse, h: head, p: print, <esc>: escape):This is a list of commands you can use to maneuver through Trace buffer:

• <cr>: display the next set of messages in the buffer.• r: display the previous set of messages in the buffer.• h: go to the first messages in the buffer and display messages from

that point.• p: go to the first message in the trace buffer and display all the

messages in the buffer. (Useful when you want to capture the entire trace buffer to a file.)

• <esc>: go to previous menu.

NotePressing any other key displays the next four frames.



Figure 35. Examine CCS L2 Trace Buffer

number : 3637 size : 55 time : 22-FEB-1999 18:33:47 port : 3 dir : out

frame : I c/r : cmd p/f : 0 n(r) : 1 n(s) : 1P.Disc : 0x08 CRef.L.F.V:2 0 00002 Msg.Type:SETUP (0x05)

B.Cap (0x04) length = 3 : 88 A0 CFDLC I(0x19) length = 2 : 41 80LLCP (0x48) length = 25 : 09 10 34 10 B4 0A 30 10 30 90 0B 30 10 30 90 0D

0F 50 0F D0 0E 0F 50 0F D0Cing.No (0x6C) length=5 : 11 80 31 30 30Ced.No (0x70) length=1 : 91PDU : 00 01 04 06 08 02 00 02 05 04 03 88 A0 CF 19 02 41 80 48 19 09 10 34 10PDU : B4 0A 30 10 30 90 0B 30 10 30 90 0D 0F 50 0F D0 0E 0F 50 0F D0 6C 05 11PDU : 80 31 30 30 70 01 91

number : 3638 size : 55 time : 22-FEB-1999 18:33:47 port : 4 dir : in

frame : I c/r : cmd p/f : 0 n(r) : 1 n(s) : 1P.Disc : 0x08 CRef.L.F.V:2 0 00002 Msg.Type:SETUP (0x05)

B.Cap (0x04) length = 3 : 88 A0 CFDLCI (0x19) length = 2 : 41 80LLCP (0x48) length = 25 : 09 10 34 10 B4 0A 30 10 30 90 0B 30 10 30 90 0D

0F 50 0F D0 0E 0F 50 0F D0Cing. No (0x6C) length = 5 : 11 80 31 30 30Ced. No (0x70) length = 1 : 91PDU : 00 01 04 06 08 02 00 02 05 04 03 88 A0 CF 19 02 41 80 48 19 09 10 34 10PDU : B4 0A 30 10 30 90 0B 30 10 30 90 0D 0F 50 0F D0 0E 0F 50 0F D0 6C 05 11PDU : 80 31 30 30 70 01 91


frame : I c/r : rsp p/f : 0 n(r) : 1 PDU : 02 01 01 06

number : 3640 size : 4 time : 22-FEB-1999 18:33:47 port : 4 dir : in

frame : I c/r : rsp p/f : 0 n(r) : 1 PDU : 02 01 01 06


frame : I c/r : cmd p/f : 0 n(r) : 1 n(s) : 1P.Disc : 0x08 CRef.L.F.V : 2 12 32770 Msg.Type:CONN (0x05)

DLCI (0x19) length = 2 : 41 80LLCP (0x48) length = 20 : 09 10 34 10 B4 0A 30 10 30 90 0D 0F 50 0F D0 0E 0F 50 0F D0

Cing. No (0x6C) length = 5 : 11 80 31 30 30Ced. No (0x70) length = 1 : 91PDU : 00 01 06 06 08 02 00 02 05 04 03 88 A0 CF 19 02 41 80 48 19 09 10 34 10PDU : 90 0D 0F 50 0F D0 0E 0F 50 0F DO




Screen Terms for Examine Level 2 Trace Buffer

This table describes the terms used in the CCS L2 Trace Buffer screen.

Term Description

number Captured frames are given a number. This is the number for the frame being displayed (from 0 to 65535). Gaps in the list indicate that the corresponding frames were not captured.

size Indicates the number of bytes in the frame.

time Indicates the data and time the frame occurred.

port Indicates the number of the port over which the frame travelled.

dir Indicates the direction the frame travelled:• in: the frame was received from the network• out: the frame was sent to the network

frame Indicates the type of frame received:• Information: I• Supervisory: RR, RNR, REJ• Un-numbered: SABME, DM, UI, DISC, UA, FRMR, XID

If the frame is not one of the above, it is reported as Unknown.

c/r Indicates the setting of the c/r (Command/Response) bit in the address field of the frame:

• cmd: a 0 was in the c/r field• rsp: a 1 was in the c/r field

p/f Indicates the setting of the p/f (Polled/Final) bit in the control field of the frame.

n(r) Displayed only if frame is of type Information or Supervisory. Indicates the n(r) (frame received acknowledgment number) value in the frame.

n(s) Displayed only if frame is of type Information. Indicates the n(s) (frame transmit sequence number) value in the frame.

P.Disc: Indicates the value of the protocol discriminator field of the frame. For Q.933 FR SVC procedures, this value should be 0x08.

PDU Protocol Data Unit: Displays the content of the frame in hexadecimal format.



Msg.Type: Indicates the message type and its hexadecimal code:• 0x01, "ALERTING"• 0x02, "CALL.PROC"• 0x07, "CONN"• 0x0f, "CONN.ACK"• 0x03, "PROG"• 0x05, "SETUP"• 0x45, "DISC"• 0x4d, "REL"• 0x5a, "REL.COMP"• 0x60, "SEG"• 0x7d, "STATUS"• 0x75, "STATUS.ENQ"

If the message is not one of the above, it is reported as "Unknown"

NoteAfter the Msg Type is displayed, the screen lists the Information Elements and their contents in the order they were found. The contents of the IEs are displayed in Hex format. Individual IEs are given names and corresponding codes as follows:

B.Cap 0x04, Bearer Capability

Cause 0x08, Cause

C.State 0x14, Call State

Ch.Id 0x18, Channel Identifier

DLCI 0x19, Data Link Connection ID

LLCP 0x48, Link Layer Core Parameters

Conn.No 0x4C, Connected Number

Conn.SA 0x4D, Connected Subaddress

Rpt.Typ 0x51 Report Type

Liv 0x53 Link Integrity Verification

PVC.Sta 0x57 PVC Status

TP 0x6A Traffic Priority

Cing.No 0x6C, Calling Number

Cing.SA 0x6D, Calling Subaddress

Ced.No 0x70, Called Number

Ced.SA 0x71, Called Subaddress

LL.Comp 0x7C, Low Layer Compatibility

Us.Info 0x7E, user to User Information

TLck.Sft 0x95 Locking Shift

Unknown Any frame not in the above set.





View Level 2 Trace

Introduction While the Examine CCS L 2 Trace Buffer allows you to examine the trace results stored in the buffer, the View CCS L2 Trace, allows you to see the trace results in real-time.

CautionWhen you use this feature, all the messages in the capture buffer are deleted.

Procedure To use the View CCS L2 Trace feature, perform these steps:

NoteThe fields in this screen are described in the table on page 138.

Figure 36. View CCS L2 Trace Screen

Step Action



3 Select View CSS L2 Trace from the menu.

4 The View CCS L2 Trace screen appears. Figure 36 is an example of what such a screen can look like.This screen is similar to the one you see with the Examine CCS L2 Trace Buffer function (see Figure 35). However, the View screen displays individual messages as they occur in real-time.To leave this screen press <esc>.


frame : I c/r : cmd p/f : 0 n(r) : 1 n(s) : 1P.Disc : 0x08 CRef.L.F.V:2 0 00002 Msg.Type: SETUP (0x05)

B.Cap (0x04) length = 3 : 88 A0 CFDLC I(0x19) length = 2 : 41 80LLCP (0x48) length = 25 : 09 10 34 10 B4 0A 30 10 30 90 0B 30 10 30 90 0D

0F 50 0F D0 0E 0F 50 0F D0Cing.No (0x6C) length=5 : 11 80 31 30 30Ced.No (0x70) length=1 : 91PDU : 00 01 04 06 08 02 00 02 05 04 03 88 A0 CF 19 02 41 80 48 19 09 10 34 10PDU : B4 0A 30 10 30 90 0B 30 10 30 90 0D 0F 50 0F D0 0E 0F 50 0F D0 6C 05 11PDU : 80 31 30 30 70 01 91


Frame Relay Access (FRA)


Support The Frame Relay Access (FRA) option supports:

• Frame Relay DCE Access ports on the Vanguard nodes• A Frame Relay user access port for a Frame Relay Access Device (FRAD)

that conforms to Frame Relay DTE standards• Up to 254 DLCIs over one physical link, thereby decreasing the number of

physical links required between the node and a FRAD• Transmitting and receiving Frame Relay data across Vanguard networks with

other FRA ports or from an FRA port to a 6520 router• Configurable support of the ANSI Standard, T1.617 Annex D Local

In-channel Signalling and LMI control protocols• Configurable support of ITU-T Standard, Q.933 Annex A

Number of Configured Stations

Frame Relay Access can be used with Vanguard nodes. There can be up to 254 Frame Relay stations configured on each FRA port, with each Frame Relay station having a unique DLCI (Data Link Connection Identifier) configured for it.

Each FRA station supports one virtual circuit. Network topology, performance considerations, and memory constraints may limit the actual number of FRA stations per node. The total number FRA stations configured depends on the Vanguard product is being used. For example, the 6507 allows a maximum of 64 FRI stations through the use of Port 1 and Port 2.

X.25 and FRI Annex G Support

FRA ports can be connected across a Vanguard network using X.25 or FRI Annex G to provide an end-to-end Frame Relay network. This network can provide end-to-end Frame Relay service for a cost substantially lower than that of a network formed from full-featured Frame Relay switching nodes.

Additionally, FRA stations can be connected across Vanguard nodes, using FRI Bypass PVC Connections, or another FRA station using a Bypass PVC connection.

Bandwidth The bandwidth of an FRA port is equal to the speed of the physical link, regardless of the number of logical links configured.




List of Features The FRA port provides the following features:

Feature Description

Frame Relay User Access Port Provides a DCE Frame Relay user access port for a FRAD that conforms to FR-DTE standards. The FRAD can connect to another FRAD at another FRA port across the Vanguard network. The FRA port can also allow co-located routers to connect to the local router within a Vanguard node.

Invalid Frame Recognition Detects frame lengths exceeding the operating limits of FRA and generates reports upon receipt of invalid frames.

Transmission Error Detection Checks data integrity of a received frame by a Cyclic Redundancy Check (CRC). The CRC characters identify possible errors at the link level.

Annex A Support Supports ITU-T Standard, Q.933Annex A for PVCs.

Annex D/LMI Support Provides configurable support for Annex D Local In-channel Signalling protocol of ANSI Standard T1.617 or for Local Management Interface (LMI). Support of these protocols enables the FRA port to notify the user of a Permanent Virtual Circuit (PVC) outage.

Frame Size Supports a maximum frame size of 4590 bytes.

Setting FECN and BECN Sets Forward Explicit Congestion Notification (FECN) and Backward Explicit Congestion Notification (BECN) when the local network link gets congested.

254 Frame Relay Connection Allows a maximum of 254 logical connections per port.


Call Connection for FRA Station


What You Need to Configure

The configured Route Selection table and PVC Setup table are used to route data across FRI/FRA ports/stations. For more information about the Route Selection Table, refer to the Vanguard Basics Manual.

Two types of connection setups are used to connect one FRA station to another, either local or remote, across an intervening network. One is an X.25 SVC from one FRA station to another (Switched Virtual Circuit over X.25 or FRI Annex G) and the other is a PVC, typically from one local station to another (using PVC Frame Relay Bypass).

FRA X.25 Configuration - Local

Two setups must be correctly configured for a successful local FRA autocall connection. These are listed below and identified in Figure 37:

• Autocall Parameters, and• Remote Connection ID Parameters

Autocall ParametersEach FRA Station can autocall either a destination FRA port or WAN Adaptor (LCON) using:

Node Address + Subaddress200 + 03 (destination FRA Port)200 + 94 (LCON)

In each case:

• The main part of the called address, and the subaddress, must equal the destination node address.

• The subaddress must match the port number of the remote FRA station, or the WAN Adaptor resource subaddress.

Remote Connection ID ParameterThe calling FRA Station’s Remote Connection ID parameter setting is equivalent to:

• The destination FRA Station Number, or• LAN Connection Entry Number

The Remote Connection ID setting is placed in the CUD field (third byte) of the Call Request.

FRA X.25 Configuration - Remote

Two setups must be correctly configured for a successful remote FRA configuration. These are listed below and identified in Figure 37:

• Route Selection Table, and• Remote Connection ID Parameters

Route Selection Table An entry must be present in the Route Selection Table at the target Vanguard node to direct the autocall to either the local FRA port or local LCON where the table’s “Destination” is equal to:

• “LCON” for the LCON (WAN Adaptor)• “FRA-#” for the FRA port where “#” is the port number




Remote Connection ID parameterThe Remote Connector ID then determines which FRA station or LCON entry to choose.

The calling FRA Station’s Remote Connection ID parameter setting is equivalent to:

• The destination FRA Station Number, or• LAN Connection Entry Number

The Remote Connection ID setting extracted from the CUD field (third byte) of the Call Request is used to select the specific FRA station, or WAN Adaptor LCON, to which the call is connected.

Figure 37. FRA Call Connection Between 6520 Nodes

FRA PVC Configuration

An FRA station is connected directly to either another FRA or FRI station using the PVC Bypass mode (Figure 38). Connections of this type can only be made using the Network Services PVC Table.

Figure 38. FRA PVC Bypass Connections

Autocall

Autocall

Route Selection Table

Address Destination

20003 FRA-3

20094 LCON

20003 C0 0010 02

20094 C0 0010 05

1

2

FRA

1

2

FRA

LAN

Forw

arde

r

5

WA94

03

6520 Node 200 Node 100 6520

1FRA

01

1

2

FRA03

1FRI

02

PVC Bypass Connections

Source AddressFRA-3S1

Source AddressFRA-3S2

Destination AddressFRA-1S1

Destination AddressFRA-2S1

Source Address

Destination Address

FRA-3S1 FRA-1S1

FRA-3S2 FRI-2S1


Configuring the Frame Relay Access (FRA)


Introduction This section describes how to configure the FRA port on a Vanguard node.

CTP Menus Refer to the diagram in Figure 39 to locate the various menus when selecting configuration parameters.

Figure 39. Configure FRA Port Record

Main Menu

Configure

Port

Null X25 FRI PAD

*Port Type

Connection TypeClock SourceClock SpeedInvert TX ClockControl Protocol SupportControl Protocol OptionsDiscard Protocol OptionsBi-Directional Annex A/Annex D SupportSubaddressT391/nT1 Poll TimerT392/nT2 Verification TimerN391/nN1 Full Status Polling CycleN392/nN2 Errors During Monitored EventsN393/nN3 Monitored Events

Port Number

FRA




Configuring the FRA Port Record

To define the FRA Port, perform these steps:

FRA Port Table Parameters

These are the parameters that make up the FRA Port Table. Unless otherwise indicated, perform a Port Boot to implement changes to these parameters.

NoteIf you have enabled Ease of Configuration, you need to boot only the port to make changes to the parameters marked with an asterisk. For more information, refer to the Ease of Configuration section in the introductory portion of the Basic Protocols Manual, (Part Number T0106).

Step Action

1 Select Configure from the Main menu.

2 Select Port from the Configure menu.

3 At the prompt, enter the number of the port you want to configure. Set Port Type to FRA. Then, configure the FRA Port record parameters.

NoteRefer to “FRA Port Table Parameters”, for parameter values and descriptions.

Port Number

Range: 1 to 54

Default: 1

Description: Specifies the port number for the Frame Relay Access port you are selecting.

Port Type

Range: NULL, PAD, MUX, X25, FRI, FRA

Default: X25

Description: Determines the type of port you are configuring.• NULL: Reserves the port for future use.• PAD: Allows the port to be connected to a device such as a

terminal, personal computer, or printer.• MUX: Allows the port to be connected to a VanguardMS

Muxport device.• X25: Allows the port to be connected to another, usually

high-speed, device such as another Vanguard or a network.• FRI: Frame Relay Interface Port.• FRA: Frame Relay Access Port.

NotePerform a Node boot to implement changes to this parameter.



Connection Type

Range: SIMP

Default: SIMP

Description: Specifies the control signal handshake and clocking required (SIMP = Simple, no inbound control signals required) for a connection to be made to this port.

Clock Source

Range: INT, EXT, EXTINT, EXTLP

Default: EXT

Description: Specifies the clock source to be used.• INT: Internal clock source (Vanguard provides clocking).• EXT: External clock source (external device provides

clocking).• EXTINT: Internal receive and external transmit clock source

(DCE only).• EXTLP: External receive and loopback clock source (DTE

only). EXTLP must be configured with EXTINT.

Clock Speed

Range: 1200 to 2048000

Default: 64000

Description: Specifies the port speed in bps.

NoteThe actual speed may be limited by the type of hardware and the “clock source” parameter.

Invert Tx Clock

Range: No, Yes

Default: No

Description: Specifies whether the phase of the transmit clock is to be inverted.Set this parameter to Yes when using an X.21 electrical interface, and when Clock Source equals EXT, Clock Speed is set to a high value, and the cable is less than 6 meters (20 feet).

NoteThis parameter only appears on Vanguard 6560 physical Frame Relay ports.




Control Protocol Options

Range: NONE, ASYNC, NBIT, DBIT

Default: NONE

Description: These options control the PVC management protocol:• NONE: No option selected• ASYNC: The port sends/receives asynchronous A-bit if it is

performing Network side protocol functionality. In addition, this option suppresses the sending of unsolicited Full STATUS messages.

• NBIT: The port sends and accepts N-bit messages. The port ignores N-bit in messages if this value is not specified.

• DBIT: The port sends and accepts D-bit messages. This forces ASYNC to be specified (DBIT+ASYNC).

Discard Control Options

Range: NONE, DEBIT

Default: NONE

Description: Specifies the discard action due to congestion within the node.• NONE: No additional actions are taken.• DEBIT: Frames marked DE is discarded when the node

indicates onset buffer pool congestion. Frames marked DE is discarded by a station when the station perceives onset of adjacent port congestion.

T391 Poll Timer

Range: 5 to 30

Default: 10

Description: This is the link integrity verification timer. The port sends status enquiry messages to the network every T391 seconds.



Bi-Directional Annex D/Annex A Support

Range: BI, UNI

Default: UNI

Description: Specifies the role that the port takes for performing the PVC management protocol:

• BI - The port enforces bidirectional PVC management protocol, both User and Network side. (Enables the ANSI T1.617 Annex D or Q.933 Annex A to pass command or response messages in either direction.)• UNI - The port enforces PVC management Network side

only.

NoteThis parameter functions only when the Control Protocol used on the port is ANNEX_A or ANNEX_D.

Subaddress

Range: 0 to 3 decimal digits

Default: Port number

Description: Specifies the subaddress for the FRA port. Incoming calls addressed to this node and subaddress comes to the FRA port for this SVC connection. The subaddress is appended to the called address of the Call Request packet generated and sent by the initiating FRA station.

T392/nT2 Verification Timer

Range: 5 to 30

Default: 15

Description: This is the timer for verification of the polling cycle. The port expects status enquiry messages every T392 seconds. This only applies when PVC management is bi-directional.




Control Protocol Support

Range: Annex D, Annex A, LMI, AUTO, NONE

Default: NONE

Description: Determines the type of control protocol support enabled. • LMI, Annex-D, Annex-A: report on the status of Frame Relay

PVC connections• Auto: allows the unit to automatically determine the protocol

being used (Annex D, Annex A, or LMI)

N391/nN1 Full Status Polling Cycle

Range: 1 to 255

Default: 6

Description: Specifies the Full Status polling cycle. The port uses this parameter when it is running the user side of PVC management protocol. It sends a Full Report STATUS ENQUIRY message to the network every N391 polls.

N392/nN2 Errors During Monitored Events

Range: 1 to 10

Default: 3

Description: Specifies the error threshold. This is the number of errors during N393 events that cause stations related to the event to be declared inactive. Set this value to be less than or equal to N393.

N393/nN3 Monitored Events

Range: 1 to 10

Default: 4

Description: Monitored events count for measuring N392. N392 errors during N393 events causes the station to be declared inactive. Set this value to be greater than N392.



Configuring the FRA Station Record

Follow these steps to configure the FRA Station record:

Example Figure 40 shows the CTP menu path to the FRA Station record parameters.

Figure 40. Configuring the Frame Relay Access Station Record

NoteFor an FRA station to be created and operational, its FRA Station Record must be configured and saved in configuration memory.

Step Action


2 Select Configure FRA Stations from the CTP Configure menu.

3 At the prompt, enter the number of the port for which you want to configure stations.

4 At the prompt, enter the number of the station you want to configure.

5 Configure the FRA Station record parameters as they appear.

NoteRefer to Figure 40 to locate the menus used when configuring FRA Stations.

Main Menu

Configure

FRA Stations

Port NumberStation NumberDLCIAutocall MnemonicAutocall TimeoutMax Number of Autocall AttemptsRemote Connection IDTraffic PriorityBilling RecordsMax Inbound Queue




FRA Station Record Parameters

These are descriptions of the parameters that make up the FRA Station Record.

Port Number

Range: 1 to 54

Default: 1

Description: Port Number is the physical port position at the rear of the hardware unit and is also the reference number for the port record. The port number selected must be for a Frame Relay Access port.

Station Number

Range: 1 to 254

Default: 1

Description: Identifies the station being configured.

Data Link Connection Identifier (DLCI)

Range: 16 to 1007

Default: Station number + 15

Description: The DLCI for the station on the FRA port and must match the DLCI configured on the FRAD attached to the port.

NoteDLCI numbers 0 to 15 and 1008 to 1023 are reserved for management of the FRA link and cannot be used.


Autocall Mnemonic

Range: Up to 8 alphanumeric characters

Default: (blank)

Description: A string which specifies an address in the Mnemonic table is used to create a switched virtual circuit through the network over which Frame Relay traffic passes. When left blank, the station can only answer calls.




Autocall Timeout

Range: 5 to 255

Default: 5

Description: Specifies the time (in seconds) after an unsuccessful autocall attempt the FRA station waits before issuing another request.


Maximum Number of Autocall Attempts

Range: 0 to 255

Default: 4

Description: Specifies how many times the FRA station attempts to establish an autocall connection before giving up. To continuously make call attempts, set to zero (0).


Remote Connection ID

Range: 1 to 254

Default: 1

Description: The Remote Connection ID is put in the Call User Data (CUD) field of the Call Request packet generated for the Autocall. It is the third byte of the X.25 protocol ID field. This parameter specifies the station number of the remote FRA port or the LCON number of the remote node to be called.


Traffic Priority

Range: LOW, MED, HIGH, EXPEDITE

Default: HIGH

Description: Specifies the traffic priority of this FRA station.





Billing Records

Range: OFF, ON

Default: OFF

Description: Enables or disables the storing and printing of billing records for the FRA station.


Max Inbound Queue

Range: 0, 100 to 2500

Default: 2500

Description: This specifies the maximum number of frames that may be queued in the inbound queue. Choose a lower value if the network experience unacceptable delays because of excessive growth of the inbound queue. When set to zero (0), the software functions as if there were no inbound queue.


FRA Operations

FRA Operations

In This Section This section describes the following FRA operations:

• Booting FRA Ports and Stations• Examining FRA configuration records• Port, Station, Channel Control



FRA Operations

Boot Command

Introduction Booting updates operational parameters of a node using the FRA parameters stored in configuration memory (CMEM).

Booting the FRA Port and Station

A Port boot clears all calls on that port. Any changes to operational parameters do not occur until a boot is completed.

A Station Boot clears the call on that station. Any changes to operational parameters do not occur until a boot is completed.

Booting an FRA Port

To boot the FRA Port:

Booting an FRA Station

To boot the FRA Station:

NoteIf you change the number of SVCs, or PVCs, you receive a message similar to one of the following:

When one of these messages is received, you must perform a node boot to activate the configuration change for the port or station.

Step Action

1 Select Boot from the Main menu, then select Port.

2 At the prompt, select the port number you want to boot.

Step Action

1 Select Boot from the Main menu, then select Station.

2 At the prompt, select the station number you want to boot.

Error Explanation

CANNOT BOOT PORT #p Topology or # of stations has changed


FRA Operations

Examine Command

Introduction Once you have defined the FRA parameters and stored them in Configuration Memory, you can verify them with the Examine command.

Examining the FRA Port Record

To examine the Port Record:

Screen Example This is what you see when you examine the FRA Port record.

Figure 41. Port Record Examination, Port 1

Step Action


2 Select Port from the Examine menu.

3 At the prompt, enter the number of the port you want to examine. See Figure 41.

Port Record Examination

Port Number: 1/1

Node: Address: Date: Time:Port Record Examination: Port 1 Page: 1 of 1

[1] *Port Type: FRA[1] Connection Type: SIMP[1] Clock Source: EXT[1] Clock Speed: 384000[1] Control Protocol Mode: None[1] Subaddress: 03[1] Bidirectional Annex D




FRA Operations

Examining the FRA Port Stations

To examine the FRA Port Stations:

Screen Example This is what you see when you examine the FRA Station record.

Figure 42. FRA Station Examination, Port 1, Station 1

Step Action


2 Select FRA Stations from the Examine menu.

3 At the prompt, enter the numbers of the port and the station you want to examine.

NoteFigure 42 shows a display similar to the one that appears on the screen.

Port Number: 1/1Station Number: 1/1

Node: Address: Date: Time:Frame Relay Station Examination: Port 1, Station 1 Page: 1 or 2

[1] DLCI: 16[1] Autocall Mnemonic:212A[1] Autocall Timeout: 5[1] Maximum Number of Autocall Attempts: 4[1] Remote Connection ID: 1[1] Traffic Priority: HIGH[1] Billing Records: OFF



FRA Operations

Non-Octet Aligned Errors and CRC Errors

Non-Octet Aligned Error

Non-Octet Aligned errors normally identify problems caused by the transmission line typically due to clocking problems. A Non-Octet Aligned error indicates an invalid frame that is not divisible by eight. Frames are constructed using characters of eight bit lengths. When at least one bit in the frame is missing, the frame is considered an invalid frame and is discarded. For each frame that is discarded in this manner, the Non-Octet Aligned field is incremented by one. Some resolutions to a Non-Octet Aligned Error are:

• Changing the idle from mark to flag• Changing the idle from flag to mark• Inverting the Tx Clock• Calling your Telco (to change a piece of hardware in the switch)• Changing your cable

Octet An octet is eight bits (commonly known as a byte).

CRC Error Indicates the number of errors detected by Cyclic Redundancy Check (CRC) since last node boot or reset of statistics. A frame that is received with a CRC error is still divisible by eight, but one or more bits are corrupted in the frame. When a CRC frame is received the frame is discarded and a CRC error is logged.

NoteCRC errors are typically caused by line disturbances.Non-Octet errors are typically caused by clocking problems.

Error Number (Hex) Description

Receive Frame Non-Octet alignment indication error

0F Indicates an invalid frame that is not divisible by eight.

Receive Frame CRC error indication

12 Indicates that a frame received contains one or more corrupted bits.



FRA Operations

Port/Station/Channel Control Command

Introduction This section describes commands for enabling/disabling FRA Ports and FRA Stations.

Enabling and Disabling

To Enable/Disable a selected FRA Port or FRA Station:

Enabling the FRA Port or Station

Enabling the FRA Port or FRA Station brings the port or station back online after it has been disabled from the CTP. To enable the FRA Port or Station:

Disabling the FRA Port or Station

Disabling the FRA Port or FRA Station brings it offline and clears all calls on that port or station without deleting its configuration record. To disable the FRA Port or FRA Station:

Step Action

1 Select Port/Station/Channel Control from the Main menu.

2 From here you can choose one of these commands:• Enable Port• Disable Port• Enable FRA Station• Disable FRA Station

Step Action

1 Select Enable FRA Port or Enable FRA Station from the Port/Station Channel Control menu.


Step Action

1 Select Disable FRA Port or Disable FRA Station from the Port/Station Channel Control menu.



FRA Status/Statistics


Introduction This section describes the Vanguard statistics used in FRA. You can use the information appearing on the following screens to monitor the operation of a node.

Detailed Port Statistics

Detailed Port Statistics provide status reports about various operations of the node. To view the Detailed FRA Port Statistics:

Figure 43. Detailed FRA Port Statistics - Page 1 of 4

Step Action


2 Select Detailed Port Statistics from the Status/Statistics menu.

3 At the prompt, enter the number of the selected port. See Figure 43.

Node: Address: Date: Time:Detailed FRA Port Statistics: Port 1 Page: 1 of 4

Port Number: 1Port Speed: 19206 Operating Control Protocol: None

Data Summary: Last Statistics Reset:IN OUT IN OUT

Characters: 0 0 Characters/sec: 0 0Frames: 0 0 Frame/sec: 0 0Av Fr size: 0 0 Port Util.: 0% 0%

Physical/Frame Relay SummaryCRC Errors: 0 Overrun Errors: 0Frame Length Errors 0 Underrun Errors: 0Unknown DLCI count: 0 Last Unknown DLCI: 0

Interface Summary: EIA-232-D DCE INPUT OUTPUTDTR RTS MB P14 DSR DCD RI CTS

State: Connected (SIMPLE) L L L L H H L H








LMI Link Statistics:IN OUT IN OUT

LIV Status Enq: 0 0 LIV Status: 0 0Full Status Enq: 0 0 Full Status: 0 0Async Updates: 0 0

T391/nT1 Timeouts: 0T392/nT2 Timeouts: 0 Seq Num Mismatch 0PVC Mgm Link State: up



Number of Operating Stations: 2





Screen Terms for Detailed FRA Port Statistics

This table describes the terms used in the Detailed FRA Port Statistics screen.


Stn# DLCI Adm A Aj N Cg Stn# DLCI Adm A Aj N Cg Stn# DLCIAdm A Aj N Cg========================================================================1 0016 1 0 1 0 0 2 0017 1 0 0 0 0


Term Description


Port Speed Identifies the message transmission speed in bps.

Data Summary • Characters: Indicates the number of characters received or transmitted since last node boot or statistics reset.

• Frames: Indicates the number of frames received or transmitted since last node boot or statistics reset.

• Av Fr size: Identifies the average number of bytes contained in the frame.



• Port Util: Factor determined by comparison of volume (characters per second) of data and clock rate for a specific port.




Physical/Frame-Relay Summary

• CRC Errors: Identifies the number of errors detected by Cyclic Redundancy Check since last node boot or reset of statistics.

• Frame Length Errors: Identifies the number of frames received with length less than 5 characters.

• Unknown DLCI count: Identifies the number of frames received with DLCI for which no station is configured.

• Overrun Errors: Identifies that an input buffer overflowed and characters were discarded.

• Underrun Errors: Identifies the number of errors detected since last node boot or reset of statistics.

• Last Unknown DLCI: Identifies the last unknown DLCI received in a frame.

Interface Summary State: Identifies the current state of the EIA signals. For a complete listing of EIA states, refer to the Vanguard Configuration Basics Manual (Part Number T0113).Input:

• DTR (Data Terminal Ready)• RTS (Request To Send)• MB (Make Busy)• P14 Ignored

These signals are monitored by the Control Terminal Port.Output:

• DSR (Data Set Ready)• DCD (Data Carrier Detect)• RI (Ring Indicator)• CTS (Clear To Send)

NoteThese signals are generated by the Vanguard port.




LMI Link Statistics This part of the statistics screen identifies the status of several LMI Link conditions. The IN and OUT values can be correlated to Received and Sent.

• LIV Status Enq: Indicates the number of LIV (Link Integrity Verification) STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset.

• Full Status Enq: Indicates the number of Full STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset. Full messages request a full status report on the status of all PVCs.

• LIV Status: Indicates the number of LIV STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset.

• Full Status: Indicates the number of Full STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset.

• Async Updates: Indicates the number of STATUS ENQUIRY messages received/sent by the port since the last Statistics Reset. Async updates are out of sequence messages that report the status of all PCVs.



• Seq Num Mismatch: Indicates the number of times a received sequence number fails to match the one expected.

• PVC Mgm State: Identifies the current status of the PVC management link.

Number of Operating Stations

Identifies the number of operational stations.










• 0 - The A-bit is inactive on the DLCI• 1 - The A-bit is active on the DLCI.





acknowledgment.


• 0 - The station is not in flow control.• 1 - The station has either sent or received LMI flow

control.




Detailed FRA Station Statistics

Viewing FRA Station Statistics

To view the FRA Station Statistics:

The screens shown in Figures 47 and 48 display information about the selected node. The table following the figures describes all the terms used in the Detailed FRA Station Statistics screens.

Resetting FRA Station Statistics

To reset FRA Station Statistics:

Figure 47. Detailed FRA Station Statistics Port 2 Station 1 - Page 1 of 2

Step Action


2 Select FRA Station Statistics.

3 Select Detailed FRA Station Stats.

Step Action


2 Select FRA Station Statistics.

3 Select Reset FRA Station Stats.

Node: Address: Date: Time:Detailed FRA Port Statistics: Port 2 Station 1 Page: 1 of 2

Port Number: 1 Station Type FRAStation Number: 1 Station Status: InactiveDLCI: 16 Station State: Peer User ActiveCongestion Detected: 0 Connection Type SVC

FRA Summary:IN OUT

FECN: 0 0BECN: 0 0DE: 0 0

Data Summary:Last Statistics Reset:IN OUT IN OUT

Characters: 0 0 Characters/sec: 0 0Frames: 0 0 Frames/sec: 0 0Packets Discard: 0 0 Utilization: 0% 0%Number of Packets Queued: 0





Figure 48. Detailed FRA Station Statistics Port 2 Station 1 - Page 2 of 2

Screen Terms This table describes the terms used in the Detailed FRA Station Statistics screens.

Node: Address: Date: Time:Detailed FRA Port Statistics: Port 2 Station 1 Page: 2 of 2

Packet Summary:IN OUT IN OUT

Data 0 0 Clear Request 0 0Call Request 0 0 Clear Confirm 0 0Call Accept 0 0 Reset Request 0 0Reset Confirm 0 0


Term Description

Port Number Designates a specific port in the network diagram.

Station Number Identifies the station being configured.

Station Type FRA is the only station type that supports the FRA option.

DLCI Describes the Data Link Connection Identifier for the station on the FRA port. This must match the DLCI configured on the Frame Relay networking node.

Station Status Displays the station status:• Disabled: Station disabled from CTP.• Inactive: Initial state. SVC/PVC does not come up in the

node or the control protocol (Annex D/LMI) is not working properly.

• Active: Normal status.



Station State Displays the station state:• Disconnected: Nothing is connected.• Peer User Active: The DLCI at the other end is up and

running. Usually this means that the FRAD at the other end has requested a full status ENQ and this end has responded with a full status response.

• Adjacent Network Active: The other end of the SVC/PVC is up and running.

• Data Transfer: Data is being transferred.

Congestion Detected

Displays inbound congestion. The network is flow controlling FRA station

Connection Type • PVC: Identifies the connection type as a Permanent Virtual Connection.

• SVC: Identifies the connection type as a Switched Virtual Connection.

FRA Summary • FECN: Specifies that the Forward Explicit Congestion Notification bit has been set.

• BECN: Specifies that the Backward Explicit Congestion Notification bit has been set.

• DE: Specifies that the Discard Eligibility bit has been set.

Data Summary • Characters: Identifies the number of characters received or transmitted since last node boot or statistics reset.

• Frames: Identifies the number of frames received or transmitted since last node boot or statistics reset.

• Packets Discard: Identifies the number of packets discarded due to congestion since last node boot or statistics reset.



• Utilization: Indicates the quantity of user bytes sent down the link expressed as a percentage of the maximum number of bytes that could have been sent.

Number of Packets Queued

Current number of packets buffered since last node boot or statistics reset.





Packet Summary • Data: Identifies a packet containing user information.• Call Request: Initiates establishment a virtual circuit

with a remote DCE by sending a Call Request packet.• Call Accept: Indicate that a call was accepted. This

causes the calling DCE to receive a Call Connected packet.

• Reset Confirm: Identifies when a reset procedure is complete.

• Clear Request: Initiates call clearing. This command is issued by the DCE.

• Clear Confirm: Acknowledges receipt of a Clear Indication packet. This is sent by the calling DCE to the called DCE.

• Reset Request: Starts a data transfer on a PVC, which may be necessary if a PVC has been down but is now available. Under certain conditions this procedure can also be used by an SVC.






• 0 - The A-bit is inactive on the DLCI.• 1 - The A-bit is active on the DLCI.





acknowledgment.


• 0 - The station is not in flow control.• 1 - The station has sent or received LMI flow control.




Detailed Link Statistics

Viewing Detailed Link Statistics

To view Detailed Link Statistics:

Figure 49. Detailed Link Statistics

Step Action


2 Select Detailed Link Statistics. See Figure 49.

Node: Address: Date: Time:Detailed Link Statistics Page: 1 of 1

Type State CRC Link Data frames Utilizationentity subtype state speed date/time errors down in/out in/out====== ======= ===== ===== ========= ======= ==== ============ =============p1 FRA up 63480 0 0 79902 1%

Port 74540 2%

p1s1 FRA up 0 10-JUL-1991 0 2 73210 0%Station 04:16:35 67793 1%






Frame Relay Concentrator


Introduction In a Frame Relay Concentrator application, FRA and FRI stations are connected on an intra-node basis using Bypass connections. A node can then act as a Frame Relay Concentrator. This allows Frame Relay service providers a cost effective way to offer low volume but wide spread customer access to Frame Relay services.

This application is useful for carriers and other service providers that are interested in offering inexpensive concentration in locations that do not justify a full featured Frame Relay switch.

Frame Relay Concentrator functionality allows you to change the number of operating stations on a functioning port without a port boot or node boot. Both boot types are disruptive to normal PVC management protocol flow.

Configuration Frame Relay Concentrator is typically configured as a number of FRA ports connected to one FRI port. Figure 50 shows an example of this application.

Figure 50. Dial-On-Demand FRI over ISDN B-Channel

Adding or Removing Stations on a Functioning Port

The Concentrator functionality allows you to change the number of operating stations on a functioning port without a port boot or node boot. Both boot types disrupt normal PVC management protocol flow. To allow a new station to operate on a port without any disruption, you can use the FRI Port Station Count Update and FRA Port Station Count Update commands. These commands update the station count for an operating port; they add new stations or delete stations that have no CMEM record from the operating port. They do not update any other operating parameters for the port or other existing stations. They do not disrupt the PVC management flow, except to allow the issuing of N- and/or D-bit as appropriate.

FRA-1

FRA-2

S1

FRA-3

End User

NetworkS1

S1

S2

S2

S3

S1

S4

FRI-4

End User

End User



The update is limited to the port to which it is applied and does not propagate to adjacent stations or ports. The update can involve multiple station additions and deletions, and is a single command applied to the port. Any given station cannot, within the same update, be deleted and made new or visa versa.

When the update command is applied to a port, the actions of this command update the interconnections between adjacent stations. The interconnections are defined in the Network Services PVC Setup Table. The Boot Tables command also includes the PVC Setup Table. This way, if the connections specified in the PVC table are not as required, or are missing, you have an opportunity to make the necessary corrections to the table and boot the corrections into place using a Boot Table command.

Bit Handling An important component of the Frame Relay Concentrator application is the handling of management issues. These are:

• N and D bit handling• Asynchronous A bit handling• DE bit handling• N and A bit handling - intended to be used only for operational purposes

(rather than full management purposes). • PVC additions and deletions




Changing a Configuration Record for a Station on a Port

Adding a New Station

Follow this procedure to add a new station and update its configuration record:

If some stations are inadvertently left out of the PVC connections, then the PVC table should be updated as necessary (Configure PVC Table), and booted into memory (Boot Tables). You can than boot the unconnected station to interconnect it to its adjacent station.

Step Action


2 Select FRI Stations or FRA Stations from the Configure menu.

3 Enter the number, when prompted, of the port on which you want to configure stations.

4 Enter the number, when prompted, of the station that you want to configure.

5 Configure the PVC CMEM records and the station cmem records.

6 Boot the PVC connections into running memory by issuing the Boot Tables command from the CTP.

7 Select Port/Station/Channel Control from the CTP Main menu.

8 Select FRI Port Station Count Update or FRA Port Station Count Update to get the stations into operating mode. If the Update command is made before the PVC table connections are booted into memory, the operating stations is not interconnected.

9 Enter the port number on which the added station resides.



N and D bit handling

Overview The number of stations on a port can be changed without a node boot. Only a port boot or port update is necessary. Booting a port is a port specific action that does not propagate to any adjacent station. This isolation of booting an FRA port does not disrupt the entire operation of another FRA or FRI port. When a port or station is booted, it does not retain any history of its prior protocol state.

N bit The N bit is part of the operation of the periodic polling that occurs on DLCI 0 as the PVC maintenance procedure and indicates the presence of a newly provisioned PVC (with corresponding DLCI).

One function of periodic polling is to notify the user equipment of newly added permanent virtual circuits using a full status message. The PVC reporting procedure uses a full status message that ensures a permanent virtual circuit cannot be deleted and another added using the same DLCI without the user equipment detecting the change. The PVC reporting procedures are:

1) When you add a new permanent virtual circuit, the network sets the new bit to 1 in the PVC status information element for that PVC in a full STATUS message.

2) The network does not clear the new bit in the PVC status information element until it receives a STATUS ENQUIRY message containing a receive sequence number equal to the send sequence counter (such as the send sequence number transmitted in the last STATUS message)

3) When your equipment receives a full status message containing a PVC status information element identifying an unknown DLCI, and the new bit is set to 1, your equipment marks this PVC as new, and adds it to its list of PVCs.

NoteThe procedures for reporting new PVCs are not supported by asynchronous status messages.

D bit The D bit is used in asynchronous status messages for the timely notification of the removal of a PVC and the corresponding DLCI. The D bit uses the asynchronous STATUS message to indicate the deletion of one or more PVCs. This message is optional. Since the LIV Information Element is not included in such a message, the update is not passed between the peer entities in an assured manner. For this reason, the fact that the PVC is absent from the full report STATUS message means that the PVC is deleted. The purpose of the D bit is to provide asynchronous, timely notification of the PVC deletion. In cases where peer equipment cannot recognize the D bit, the indication that the PVC is absent is still properly indicated with the regular STATUS messages (with missing PVCs as appropriate).

The D bit is sent when a station is deleted from configuration.




FRI and FRA Port Characteristics

The FRA and FRI port types for Vanguard products operate their PVC management functions independently of each other. The N or D bit is issued by either an FRA or FRI station when a new station record is created, or an existing station is deleted. The determination for the need to issue the N bit or D bit is not transferred between the two port types. When a new station is created (or deleted) on a FRA port, for example, the N bit (or D bit) would be issued as described above. On an adjacent FRI (or Bypass connected FRA) port, no N bit (or D bit) would be issued corresponding to this activity. If there is no connectivity configured between the FRA station and an adjacent FRI station, then the A bit always remains off (A=0) for that station in the PVC status information element on the FRA port. This also applies to the FRI port in terms of when it can issue the N bit and D bit.

Adding or deleting a station, and sending the appropriate notification, can be done without disturbing the operation of the port (and the PVC management procedure). Commands on the CTP allow you to add and boot PVC stations on the port along with the corresponding N and D bit procedures. These procedures can occur without disturbing the operation of the port.

The sending of the N or D bit is a one time event which occurs the moment you create or delete a station. This remains true even if you boot the port or station, or restart the node from a power up situation or boot. The only way the N bit for a given station is re-issued is if the station is deleted and recreated.



Asynchronous A bit handling

STATUS Message The STATUS message is sent in response to a STATUS ENQUIRY message to indicate the status of permanent virtual connections, or to verify link integrity. Optionally, it may be sent at any time to indicate the status of a single PVC. The link integrity verification information element is not included in the STATUS message component of the optional asynchronous status message (the report type is equal to a single PVC asynchronous status). This optional asynchronous STATUS message contains a single PVC status information element.

NoteAsynchronous status messages do not satisfy the requirement for a status message in a given polling interval. Asynchronous status messages do not include the Link Integrity Verification Information Element and therefore are non-sequenced messages.

Asynchronous Status Message

FRI and FRA ports contain asynchronous update messages. The asynchronous status message, since it only includes the information for a single PVC, must be sent for as many stations as become active in a given reporting interval. For a large number of stations that become active at one time, this may burden the port with many status messages in a short interval, and could impact user data.

An asynchronous status message consists of a frame with these fields and (byte counts):

• flag(1)• address(2)• control(1)• protocol disc(1)• call ref(1)• message type(1)• rept type(3)• PVC status(5)• fcs(2)• flag(1)

The Annex A message is 18 bytes long. The Annex D message includes a locking shift element of one byte and therefore its length is 19 bytes.

At 64 kbps, the transmission of such a message would take 16x8/64 ms = 2 ms.

Asynchronous Updates

For any reasonable number of PVCs, the amount of time devoted to asynchronous updates occupies only a short time (20 stations can be reported in about 40 ms). This is also a one time occurrence and does not represent any steady or long lasting interference to data.

Station Status Both the FRA and FRI ports operate their PVC management protocols independently of each other. However, the status of stations on one port is passed to the connected station on an adjacent port when the stations are Bypass connected. Therefore, whatever status exists for a station on one port is reflected in the status reported on the adjacent port.




Status Reports When you boot a port or a node, the asynchronous report is not generated for the set of stations on that port. They are asynchronously reported on the adjacent port (where the status is toggled down and then up in a very short time interval). If a station is booted, the status for the station’s port and the station on the adjacent port are reported as the boot event is handled.



DE Bit Handling

Overview Discard Eligibility (DE) bit handling is normally confined to two situations:

• When a FRI station is operating in a controlled mode due to the attached network or equipment signalling a state of congestion for that station (the FRI port is receiving BECN bits in incoming frames on the DLCI for that station).

• When a station transmits data into a network above its CIR (or some other configured rate).

For more information on DE bit handling with Congestion Control, please refer to “DE-Bit Handling” on page 44.




Adding and Deleting PVCs

Overview The N bit is issued by either an FRA or FRI station (acting as a responder to STATUS) when a new station record is created and reported for the first time in a full status report.

Parameter and Port Changes

In concentrator configuration, parameter and port type changes can occur on FRI and FRA ports without the need to boot the node. This change must also take into account the ability to boot the PVC table which is used to interconnect the FRI and FRA bypass stations.

Adding a PVC Figure 51 shows an example of adding a PVC for an existing user when two different users on FRA ports are being concentrated on the same FRI port.

Figure 51. Station Addition

In the initial configuration, the stations that are defined and in use are FRA-1S1, FRA-2S1 and FRI-3S1, FRI-3S2. There is a spare station on the FRI port, FRI-3S3, which is pre-provisioned for future expansion. You can define as many spare stations on the FRI port as necessary for growth. You can leave these stations disabled until needed. They report their status in bidirectional PVC management messages as Not Active (STATUS message A bit = 0).

Attached network equipment to which the FRI port is connected can adopt a policy of not allowing this down status for disabled ports to cause unnecessary alarms. In most cases, the attached network sees the FRI port as an ordinary subscriber port which is sending status enquiry, and not actually supplying a status in a STATUS message, since the network is not sending this port a status enquiry.

You can add a new station to FRA-2, configure the new station, then boot the port. Booting the port interrupts the data for the FRA-2 user, but only effects the user on port FRA-2. You can then enable the corresponding station to FRI-3 (FRI-3S3). This station enabling does not interrupt the user on port FRA-1. Thus, by pre-provisioning stations on the consolidated FRI port, you can increase the subscription of PVCs for individual users on access ports without effecting other users.

Before FRA Station Addition After FRA Station Addition

FRA-1

FRA-2

S1

S1

S2

S3

S1

FRI-3

FRA-1

FRA-2

S1

S1S2

S3

S1

FRI-3

S2



Removing a PVC If you remove a station from the port configuration, you can use the Delete Record selection from the CTP to remove the record from cmem.

You only need to perform a port update to notify users of the addition or deletion of a new PVC. N and D bits signal the event on the PVC management protocol if stations are added, deleted, or updated with any internal connections to other stations when a station is created or deleted.



FRF.12

FRF.12

What is FRF.12? FRF.12 is the Frame Relay Fragmentation Implementation Agreement of December 1997. This agreement was developed to allow long data frames to be fragmented into smaller pieces and interleaved with real-time frames. In this way, real-time voice and non-real-time data can be carried together on lower speed links without causing excessive delay to the real-time traffic.

The VanguardMS Implementation

The VanguardMS implementation of FRF.12 allows for local packet segmentation between DTE-DCE peers across a Frame Relay UNI interface as well as end-to-end packet segmentation between Frame Relay DTE-DTE peers interconnected by one or more Frame Relay networks.

The segmentation is enabled on an interface by interface basis at the FRI port. When segmentation is enabled, all selected packets shall be sent as a sequence of segments where the size of the segment never exceeds the configured segment size. An appropriate header shall precede each segment. The criteria for packet type selection as well as header content is dependent on the type of selected segmentation type. Fragments are transmitted in the same sequence as they occurred in the frame prior to being fragmented.

When segmentation is enabled, a receiving side is able to identify the segments and reassemble them into the original packet. The receiver uses the Maximum Frame Size parameter in the Node Record to reassemble the packet. The receiving side must detect lost and miss ordered segments. Received segments are discarded when the packet reassembling cannot be completed for the following reasons:

• One or more segments are out of order• One or more segments are not received• The size of the unassembled packet exceeds the maximum allowed

packet sizeWhen a lost fragment is detected or an out of order fragment is detected on a virtual circuit, the receiving side will discard all currently unassembled and subsequent fragments for the virtual circuit until a first fragment frame is received with the Beginning bit set. Once a fragment with the Beginning bit set is found, the accumulation for a new frame begins.

The receiving side is able to detect lost segments through the use of the sequence number found in each received segment.

If an error such as a lost fragment from a transmission error or a reassembly buffer overflow, then the receiving side discards the fragments that are associated with the original frame.

When assembling a packet, the receiving side verifies the size of each unassembled packet. If the size of the packet exceeds the maximum allowed packet size, then the unassembled packet is discarded as well as subsequent fragments until a first fragment with a Beginning bit is received.


FRF.12

Fragmentation Header for Local Segmentation

The (B)eginning fragment bit is set to 1 on the first data fragment derived from the original frame and set to 0 for all other fragments from the same frame.

The (E)nding bit is set to 1 on the last data fragment and set to 0 for all other data fragments.

When the size of the data packet is less than or equal to the segment size a fragment is sent with both the (B)eginning bit and the (E)nding fragment bit set.

When the packet is received with both the (B)eginning bit and the (E)nding fragment bits set to 1 , then the frame is considered as a single segment packet.

The (C)ontrol bit is set to 0 in all fragments.

The sequence number is a binary number that is incremented for every data fragment transmitted on the circuit. There is a separate sequence number for each DLCI across the interface.

All frames on all DLCIs are preceded by the fragmentation header.

When frames are received that do not contain the fragmentation header, those frames are discarded.

FRF.12 Segmentation

When FRF.12 End to End fragmentation is enabled on a circuit, frames that exceed the configured maximum frame size must conform to the fragmentation format. Any packet with size less than the configured maximum frame size shall be transferred without change in size and is preceded by the segmentation header.

Voice and expedite data packets as well as packets on DLCI 0 and 1023 shall not be effected by End-to-End segmentation. These frames are transferred without change in size and will not be preceded by the segmentation header.

8 7 6 5 4 3 2 1

Fragmentation Header

B E C Sequence number of high 4 bits

1

Sequence number of low 8 bits

Frame Relay Header

Frame Relay Header

Frame Relay Header

Fragment Payload

Frame Check Sequence




FRF.12

Fragmentation Header for End to End Segmentation

The (B)eginning fragment bit is set to 1 on the first data fragment derived from the original frame and set to 0 for all other fragments from the same frame.

The (E)nding bit is set to 1 on the last data fragment and set to 0 for all other data fragments.

When the size of the data packet is less than or equal to the segment size a fragment is sent with both the (B)eginning bit and the (E)nding fragment bit set.

When the packet is received with both the (B)eginning bit and the (E)nding fragment bits set to 1 , then the frame is considered as a single segment packet.

The (C)ontrol bit is set to 0 in all fragments.

The sequence number is a binary number that is incremented for every data fragment transmitted on a PVC. There is a separate sequence number for each fragmented PVC between the peers.

VanguardMS Segmentation Packet

When configuring end-to-end segmentation in the Vanguard product line, there is a choice between the FRF.12 implementation or the VanguardMS Segmentation implementation. The FRF.12 implementation should be used with the end nodes in the circuit of mixed vendors. The VanguardMS implementation should be used when the end nodes of the circuit are VanguardMS Vanguard products.

With the Vanguard Segmentation, the header is of a different format than the FRF.12 header. Setting the type of segmentation to the same choice at each end node is important or else the fragmented packets are discarded by the receiving node.

8 7 6 5 4 3 2 1

Frame Relay Header

Frame Relay Header

Frame Relay Header

UI (0x03) 0 0 0 0 0 0 1 1

NLPID (0xB1) 1 0 1 1 0 0 0 1

Fragmentation Header

B E C Seq. # of high 4 bits 0

Sequence number of low 8 bits

Fragment Payload




FRF.12

FRF.12 and Third Party Products

Voice Header Insertion Parameter

Vanguard products introduce an additional proprietary voice header which is not recognized by third party products when in FRF.12 mode. A station configuration parameter called Voice Header Insertion is listed in the FRI Station Record Parameters.The Voice Header Insertion parameter controls the presence of the Voice Header in front of voice packets. Refer to “FRI Station Record Parameters” section on page 21 for more information. This parameter controls VanguardMS Voice Header insertion and removal to or from voice packets when they are transmitted or received. The parameter can be configured and takes effect only when the Station Type is BYPASS, End-to-End segmentation is Enabled and End-to-End Segmentation Type is FRF.12.

When the Voice Header Insertion parameter is set to Enable, a third party node is able to forward voice packets with the VanguardMS Voice Header.

The Voice Header Insertion parameter is set to Disabled for a station only when the node that terminates FRF.12 End-to-End segmentation is a third party product. The voice header is not inserted and a voice packet can be transferred by a third party node to a VanguardMS node.

NoteVanguardMS Segmentation Protocol with Segmentation Header for data and Voice Header for voice are part of VanguardMS proprietary voice technology. This technology can be used only between Vanguard end-points for both data and voice.

FRF.12 End-to-End Segmentation Protocol (prior to release 5.6) is an alternative to VanguardMS Segmentation Protocol providing interoperability with third party nodes for data only. Voice must be terminated at a Vanguard node.



FT1/FE1 Daughtercard Over Frame Relay


What Is the FT1/FE1 Daughtercard?

The FT1/FE1 Daughtercard provides a physical line interface to fractional T1 or E1 leased line networks. Fractional means that the FT1/FE1 daughtercard is intended for use on a fraction of the full T1/E1 Bandwidth.

The Daughtercard does not provide any new protocol or software application support. The FT1/FE1 Daughtercard supports Frame Relay and X.25 networks.

Vanguard 6400 SeriesThe 6400 Series supports up to three FT1 or FE1 Daughtercards with three channels each. Each channel connects one port to the T1/E1 network. The FT1/FE1 card functions as a T1 or E1 DSU/CSU DIM, providing up to three data pipes to physical ports.

Vanguard 320 and 34xVanguard 320 and 34x support one T1 or E1 Daughtercard only. Each Daughtercard has only one nx56/64Kbt/s channel. If the T1/E1 Daughtercard is installed in DIM site one, it uses Port 1. If it is installed in DIM site two, it uses Port 2.

Support The FT1/FE1 Daughtercard is designed to support:

• E1 with line rates of 2.048Mbps and data rates of n x 64Kbps (where n=1 to 31) per channel

• T1 with line rates of 1.544Mbps and data rates of n x 56Kbps or n x 64Kbps (where n=1 to 24) per channel

• One Vanguard 320 channel and port connected to the T1/E1 span.• One Vanguard 34x channel and port connected to the T1/E1 span.• Up to three Vanguard 6400 channels/ports connected to the T1/E1 span

All other Vanguards are not currently supported.• All other Vanguards are not supported.• All Port Types using BOP protocols.



Configuring the T1/E1 Interface in a Frame Relay Network

Introduction This section describes the screens, parameters, and procedures you use to configure the T1/E1 Interface for a Vanguard node.

Network Topology and Configuration Example

Figure 52 shows the sample topology and configuration of the T1 Interface parameters for Frame Relay. This example shows configuration of the Vanguard 6450 ports 7 and 8 and Vanguard 320 port 2, as well as the Vanguard 6450 T1 interface 1 and Vanguard 320 T1 interface 1.

Figure 52. Sample Network Topology and Configuration

V320 T1 Interface ConfigurationEntry Number 2/*Interface Type T1/First Channel Port 2/First Channel TimeSlots 1-2/First DSO Rate 56/Line Framing Type SF/Line Coding Type AMI/Transmit Clock REC/Line Build Out 0/Receiver Sensitivity LOW/Facility Data Link NONE/Receive V54 RLPB NoThreshold Value - LES 10/Threshold Value - LCV 10/Threshold Value - PCV 10/

V6450 T1 Interface ConfigurationEntry Number 1/*Interface Type T1/First Channel Port 7/First Channel TimeSlots 20,22/First DSO Rate 56/Second Channel Port 8/Second Channel TimeSlots 10-16/Second DSO Rate 64/Third Channel Port 0/Third Channel TimeSlots 0/Third DSO Rate 56/Line Framing Type ESF/Line Coding Type AMI/Transmit Clock REC/Line Build Out 0/Receiver Sensitivity LOW/Facility Data Link ANSI/Receive V54 RLPB No

Vanguard 320

P2 FRIChannel 1-P2 112 Kbps

FT1384 Kbps

Frame Relay Switch

Frame Relay Backup Switch

FT1

ISDN

T1 Network

Vanguard 6450

P7 FRA

P8 FRI

Channel 1-P7 112 Kbps

VoiceRelay

VoiceRelay

Touch Tone Phone

Touch Tone Phone

Mac/PC

Mac/PC




Configuration Process

This process describes how the T1/E1 interface is configured.

6400 Series Configuration Considerations

Consider this mapping of ports to channels when configuring a 6400 Series T1/E1 Interface.

NoteFor the 6400 Series, you can insert all three FT1/FE1 Daughtercards simultaneously.

Step Action

1 You use the configuration menus to configure the T1/E1 line according to the Service Provider’s specification.

2 You associate time slots to the application ports.

3 If... Then...

No CMEM record exists A default CMEM record isgenerated when the node recognizes an FT1/FE1 Daughtercard.

The CMEM Record does exist, but is incompatible with theDaughtercard type

The card is initialized with the appropriate default record.

T1/E1 Interface

Channel No Port No

1 1 7

1 2 8

1 3 9

2 1 10

2 2 11

2 3 12

3 1 13

3 2 14

3 3 15



Configuration Perform these steps to configure the T1/E1 Interface in a Frame Relay network:

T1/E1 Interface Configuration Menus

This section describes the menus you use to configure the T1/E1 Interface.

Figure 53. T1/E1 Interface Selection Configuration Screen

Figure 54. T1 Interface Configuration Screen

Step Action

1 Access the T1/E1 Interface Selection Configuration menu from the main Node Configuration menu.

2 Select the platform that you want to configure.

3 Access the T1/E1 Interface Configuration menu from the main Node Configuration menu.

4 Configure the parameters as specified beginning on page 190. Figure 52 shows a sample configuration.

Node: Address: Date: Time: Menu: Configure T1/E1 Interface Path:

T1/E1 Interfaces <- 6450 1,2 or 3

#Enter Selection:

Entry NumberInterface TypeFirst Channel PortFirst Channel Time SlotFirst Channel DS0 RateSecond Channel PortSecond Channel Time SlotSecond Channel DS0 RateThird Channel PortThird Channel Time SlotThird Channel DS0 RateLine framing TypeLine Coding TypeTransmit Clock

Node: Address: Date: Time:Menu: Configure Path:

Configure T1/E1 Interface

Line Build OutReceiver SensitivityFacility Data LinkV54 Receive RLBKThreshold Value - LESThreshold Value - LCVThreshold Value - PCVThreshold Value - CSSThreshold Value - ESThreshold Value - BESThreshold Value - SESThreshold Value - SEFSThreshold Value - UAS




Figure 55. E1 Interface Configuration Screen

T1/E1 Parameters These parameters make up the T1/E1 Interface:

Entry NumberInterface TypeFirst Channel PortFirst Channel Time SlotSecond Channel PortSecond Channel Time SlotThird Channel PortThird Channel Time SlotLine framing TypeLine Coding TypeTransmit ClockLine ImpedanceV54 Receive RLBKThreshold Value - LESThreshold Value - LCVThreshold Value - PCVThreshold Value - CSSThreshold Value - ESThreshold Value - BESThreshold Value - SESThreshold Value - SEFSThreshold Value - UAS

Node: Address: Date: Time:Menu: Configure Path:

Configure T1/E1 Interface

Interface Type

Range: T1, E1

Default: T1

Description: Specifies the type interface you are configuring. Configure this parameter according to the provided service.

NotePerform a Node boot to implement changes to this parameter.



First Channel Port

Range: 10, 0

Default: 10

Description: Specifies the first of the Channel/Port associations (that is, the port number associated to the First FT1/FE1 channel).Specifying 0 on the First FT1/FE1 channel indicates zero (0) data activity.

NoteThe application port must be a port using X25, or FRI. Also, the first port of each T1 or E1 Interface (ports 7, 10, and 13) must be used if the interface is installed. The second and third channel ports are optional based on the application.

First Channel Timeslots

Range: For T1: 0, 1 to 24For E1: 0, 1 to 31

Default: 1

Description: Specifies the time slot assignments for the first channel.Zero (0) indicates no timeslot selected.You can select individual or time slot ranges, for example,1-3, 10, 13-15 includes Time Slots 1, 2, 3, 10, 13, 14,15.

NoteFor the first channel, you must assign at least one timeslot. If a time slot is assigned to more than one channel, CMEM is not saved and an error message is generated. If 0 (zero) time slots are assigned to a channel, the associated port does not receive the clock and is unusable.

First Channel DSO Rate

Range: 56, 64

Default: 56

Description: Specifies the DS0 Rate for the first T1 Channel.

NoteThis parameter specified by service provider for each end of the circuit. If one end is provisioned to 56Kbs, both ends must be set to 56. This parameter applies to the T1 channel only.




Second Channel Port

Range: 0, 11

Default: 11

Description: Specifies the second of the Channel/Port associations (that is, the port number associated to the Second FT1/FE1 Channel).A 0 (zero) value means there is no data activity on the second T1/E1 Channel.

NoteThe application port must be a port using X25, or FRI. Also, the first port of each T1 or E1 Interface (ports 7, 10, and 13) must be used if the interface is installed. The second and third channel ports are optional based on the application.

Second Channel Timeslots


Default: 0

Description: Specifies the time slot assignments for the second Channel. Zero (0) indicates no channel.You can select Individual or Time Slot ranges, for example, 1-3, 10, 13-15 includes Time Slots 1, 2, 3, 10, 13, 14, 15.

Second Channel DSO Rate

Range: 56, 64

Default: 56

Description: Specifies the DS0 Rate for second T1 Channel.




Third Channel Port

Range: 12, 0

Default: 12

Description: Specifies the third of the Channel/Port associations (that is, the port number associated to the Third FT1/FE1 channel).A value of 0 means no data activity occurs for the third FT1/FE1 channel.

NoteThe application port must be a port using X25, or FRI.Also, the first port of each T1 or E1 Interface (ports 7, 10, and 13) must be used if the interface is installed. The second and third channel ports are optional based on the application.

Third Channel Timeslots


Default: 0

Description: Specifies the time slot assignments for the third Channel Time Slot. Zero (0) indicates no channel.You can select Individual or Time Slot ranges, for example, 1-3, 10, 13-15 includes Time Slots 1, 2, 3, 10, 13, 14, 15.

Third Channel DSO Rate

Range: 56, 64

Default: 56

Description: Specifies the DS0 Rate for the third T1 Channel.





Line Framing Type T1

Range: ESF, SF

Default: SF

Description: Indicates the type of framing used by the DS1 circuit.• ESF: Extended Super Frame.• SF: Super Frame.

This parameter is specified by the service provider. SF is also called D4.

Line Framing Type E1

Range: E1, E1_CRC, E1_CRC_FEBE

Default: E1

Description: Indicates the type of framing used by the DS1 circuit.• E1: D2048S or D2048U.• E1_CRC: D2048S with CRC.• E1_CRC_FEBE: D2048S with CRC and Si=FEBE.

NoteThe maximum payload data rate is 1,984 kbits/s. Framing Type E1 meets the demands for the TBR13 Structured leased line D2048S, and TBR12 UnStructured D2048U parameters. (TBR - Technical Basis for Regulation - are the standards for the E1 framing structure. D2048S or D2048U can be found in these standards.)

Line Coding Type T1

Range: B8ZS, AMI

Default: AMI

Description: Specifies the type of line coding used for T1 applications. Selects variety of zero suppression used on the T1 link.

• B8ZS: Bipolar 8 Zero Substitution. • AMI: Alternate Mark Inversion.

NoteThe FT1 card supports only the B8ZS and AMI line coding types. It dos not support the B7 line coding type as the Regional node T1/E1. This parameter is specified by the service provider.



Line Coding Type E1

Range: HDB3, AMI

Default: HDB3

Description: Selects the variety of zero suppression used on the T1 link. • AMI: Alternate Mark Inversion.• HDB3: High Density Bipolar 3.

This parameter is specified by the service provider.

Transmit Clock

Range: INT, REC

Default: REC

Description: Selects the source of the transmit clock.• INT: Internal Timing, use when timing is not provided by the

Network. • REC: Received Timing, use when connected to Public or

Private Network.

NoteIn most cases REC timing is used. INT timing is used only in point to point applications, where one unit is set to INT and the other one to REC timing. When Loopback tests are run, the unit is automatically switched to INT for the duration of the test.

Line Impedance E1

Range: 120, 75

Default: 120

Description: Specifies the line impedance as 75 ohms or 120 ohms.

NoteWhen switching impedance for 75/120 ohm, you must change the connectors to BNC/Modular 8 Pin Jack. This parameter is specified by the service provider.




Line Build Out T1

Range: 0 to 7

Default: 0

Description: Used to select the Line Build Out to match the physical interface.For a DSX Interface, set the number based on the cable length.

• 0 - 0ft to 133ft• 1 - 134ft to 266ft• 2 - 267ft to 399ft• 3 - 400ft to 533ft• 4 - 534ft to 655ft

For a DS1 Interface, set the number based on signal level.• 0 - 0dB• 5 - 7.5dB• 6 - 15dB• 7 - 22.5dB• 4 - Not valid for DS1 interfaces

NoteDS1 and DSX interfaces are provided via the same 8 Pin Modular Jack. For DS1, the service provider specifies the attenuation setting. For DSX, the installer of the cables can provide the cable length.

Receiver Sensitivity T1

Range: LOW, HIGH

Default: LOW

Description: Specifies receiver sensitivity of FT1 Daughtercard with these values:

• HIGH: -36dB - select this if the line is marginal. For some marginal cable lengths and line loss require this setting.

• LOW: -30dB - select this when connected directly to the T1 line. This allows for nominal noise immunity.



Facility Data Link

Range: NONE, ANSI, ATT

Default: NONE

Description: Specifies the use of the facility data link channel.

NoteThis parameter appears for T1 only and has no implication on the pay load data. Set it according to carrier specifications. For more information on this, refer to ANSI-T1.403 and AT&T 54016.

V54 Receive RLBK

Range: DISABLE, ENABLE

Default: DISABLE

Description: Specifies the system response to incoming V.54 loopback requests.• ENABLE: Respond to incoming V.54 loopback requests.• DISABLE: Do not respond to incoming V.54 loopback

requests.

Threshold Values for LES

Range: 1 to 255

Default: 10

Description: Specifies the Threshold value for the Line Errored Seconds (LES) report. When this value is exceeded within one 15 minute interval, a report is generated. There can be only one report per 15 minute interval.LES is a second in which one or more Line Code Violation error events are detected.




Threshold Value for LCV

Range: 1 to 255

Default: 10

Description: Specifies the threshold value for the Line Coding Violation (LCV) report. When this value is exceeded within one 15 minute interval, a report is generated. There is only one report per 15 minute interval.LCV is the occurrence of either a Bipolar Violation (BPV) or Excessive Zeroes (EXZ) Error Event.

Threshold Value for PCV

Range: 1 to 255

Default: 10

Description: Specifies the threshold value for a Path Coding Violation (PCV) report. When this value is exceeded within one 15 minute interval a report is generated. there can be only one report per 15 minute interval.The Path Coding Violation (PCV) error event is:

• for D4 and E1-nonCRC formats: frame synchronization bit error

• for ESF and E1-CRC formats: CRC error

Threshold Value for CSS

Range: 1 to 255

Default: 10

Description: Specifies the threshold value for Controlled Slip Seconds (CSS) report. When this value is exceeded within one 15 minute interval, a report is generated. There can be only one report per 15 minute interval.Controlled Slip Seconds (CSS) is the replication or deletion of an E1/T1 frame. This parameter is applicable only when the clock source is set to INT.



Threshold Value for ES

Range: 1 to 255

Default: 10

Description: Specifies the threshold value for the Errored Seconds (ES) report. When this value is exceeded within one 15 minute interval, a report is generated. There can be only one report per 15 minute interval.

• Errored Seconds (ES) for D4 and E1-non-CRC formats is a second with one or more Bipolar Violation.

• Errored Seconds for ESF and E1-CRC formats is a second with one or more Path Code Violation or one or more Out Of Frame or Controlled Slips.

Threshold Value for BES

Range: 1 to 255

Default: 10

Description: Specifies the threshold value for the Bursty Errored Seconds (BES) report. When this value is exceeded within one 15 minute interval a report is generated. There can be only one report per 15 minute interval.BES is a second with fewer than 320 and more than one Path Coding Violation error events, and no Severely Errored Frame defects. Controlled Slips are not included in this parameter. BES is not incremented during an Unavailable Second.




Threshold Value for SES

Range: 1 to 255

Default: 10

Description: Specifies the threshold value for Severely Errored Seconds (SES) report. When this value is exceeded within one 15 minute interval, a report is generated. There can be only one report per 15 minute interval.

• Severely Errored Seconds (SES) for D4 formats is a second with 1544 or more Line Coding Violations (LCV) or an OOF defect.

• Severely Errored Seconds (SES) for ESF formats is a second with 320 or more Path Code Violations or one or more Out of Frame defects or a detected AIS defect.

• Severely Errored Seconds for E1-CRC formats is a second with 832 or more Path Code Violations or one or more Out of Frame defects.

• Severely Errored Seconds for E1-nonCRC formats is a second with 2048 or more Line Coding Violations (LCV).

• Controlled Slips are not included in this parameter. Severely Errored Seconds (SES) is not incremented during an Unavailable Second.

Threshold Value for SEFS

Range: 1 to 255

Default: 10

Description: Specifies the threshold value for Severely Errored Framing Seconds (SEFS) report. When this value is exceeded within one 15 minute interval, a report is generated. There can be only one report per 15 minute interval.SEFS is a second with one or more Out of Frame defects or a detected AIS defect.



Threshold Value for UAS

Range: 1 to 255

Default: 10

Description: Specifies the threshold value for the Unavailable Seconds (UAS) report. When this value is exceeded within one 15 minute interval, a report is generated. There can be only one report per 15 minute interval.UAS is the number of seconds that the interface is unavailable. The DS1 interface is said to be unavailable after 10 contiguous SESs.




T1/E1 Interface Statistics

Introduction This section describes the menus and statistics calculated for the T1/E1 Interface.

Screens The screens used and terms calculated for a T1/E1 Interface are described as follows. Each statistics screen is followed by the terms on that menu.

Figure 56. Sample Detailed Interface Statistics Screen - Page 1

This screen calculates statistics for diagnostic tests.

Node: Address: Date: Time: Detailed T1/E1 Interface Statistics Page: 1 of 9

Interface Type: E1 - 2Time Since Last Stats Reset: 8-FEB-2036 1:24:12Alarm State: NONEChannel State: NORMAL | NORMAL | NORMALLine Error Count:24 Hour Totals LES LCV PCV CSS ES BES SES SEFS UAS 0 0 0 0 0 0 0 0 0Current 15 Minutes Interval Time Elapsed in Current Interval: 0 LES LCV PCV CSS ES BES SES SEFS UAS 0 0 0 0 0 0 0 0 0 Press any key to continue ( ESC to exit ) ...

Screen Term Description

Alarm State for T1 Indicates conditions generating alarms for the T1 Interface.

Waiting Indicates that the T1 port has never been in frame/sync since the T1 port was booted.

None Normal Operation

Red Loss of signal

Yellow Reception of RAI/Yellow alarm

Blue Reception of AIS/Alarm Indication Signal

Line Loop back TELCO test

Payload Loop back TELCO test

POWER ON This state is the starting state after the unit is powered up and before line activity is detected.

Alarm State for E1 Indicates conditions generating alarms for the E1 Interface.

NONE Normal Operation

LOS Loss of Signal (Red)

FAS Frame Alignment Signal

LOF Loss of Frame

RAI Reception of RAI/Yellow alarm (Yellow)



Figure 57. Sample Detailed Interface Statistics 15 Minutes Stats Screen

This screen calculates statistics for errors. The terms are described as follows:

RAI+E Reception of RAI with constant FEBE errors

AIS Reception of Alarm Indication Signal (Blue)

POWER ON This state is the starting state after the unit is powered up and before line activity is detected.

Channel State 1st, 2nd, 3rd

Indicates the conditions generating status for the channel.

NORMAL Normal operation: T1/E1 line is up

DOWN T1/E1 line is down or unavailable, or has no time slots

TELCO Loop Channel is placed in remote loopback by carrier

L3 Loop Channel is placed in remote loopback by remote unit or BERT test equipment

L2 Loop Channel is placed in local loopback

Screen Term Description (continued)

Node: Address: Date: Time: Detailed T1/E1 Interface Statistics Page: 2 of 9Interface Type: E1 - 2

Interval: LES LCV PCV CSS ES BES SES SEFS UAS00:15 0 0 0 0 0 0 0 0 000:30 0 0 0 0 0 0 0 0 000:45 0 0 0 0 0 0 0 0 001:00 0 0 0 0 0 0 0 0 001:15 0 0 0 0 0 0 0 0 001:30 0 0 0 0 0 0 0 0 001:45 0 0 0 0 0 0 0 0 002:00 0 0 0 0 0 0 0 0 002:15 0 0 0 0 0 0 0 0 002:30 0 0 0 0 0 0 0 0 002:45 0 0 0 0 0 0 0 0 003:00 0 0 0 0 0 0 0 0 0


Screen Term Indicates...

Interval The time period for which error count statistics are calculated.

LES Line Error Seconds count

LCV Line Coding Violation count

PCV Path Coding Violation count

CSS Controlled Slip Seconds count

ES Errored Seconds count

BES Bursty Errored Seconds count




Figure 58. Sample Detailed Port Statistics - Page 1

The only term new to this statistics screen is Channel State. It also appears on the screen shown in Figure 56.

SES Severely Errored Seconds count

SEFS Severely Errored Framing Seconds count

UAS Unavailable Seconds count

Screen Term Indicates... (continued)

Node: Address: Date: Time: Detailed Frame Relay Port Statistics: Port 1 Page: 1 of 4 Port Number: 1 Port Type: Frame RelayPort Status: Down Port Speed: 336000 Port State: Disc. Phase Link Address: DCE Port Utilization In: 0% Port Utilization Out: 0% Call Summary: SVC PVC Maximum: 0 0 Current: 0 0 Data Summary: Last Statistics Reset: Date: 0:00:00 IN OUT IN OUT Characters: 0 0 Characters/sec: 0 0 Packets: 0 0 Packets/sec: 0 0 Frames: 0 0 Frames/sec: 0 0 Number of Packets Queued: 0 Interface Summary: T1-1 Channel 2 Channel State: Normal


Screen Term Description

Channel State Indicates conditions generating status for the T1/E1 Interface channel associated with the port shown.



Diagnostics

Introduction Port diagnostics for Local Loop, L2 Loop, and L3 Loop support T1/E1 interfaces.

Loopback Test Limitations

These limitations apply to Loopback tests:

• When Local Loop, L2 Loop, or L3 Loop tests are invoked for a port associated with a T1E1 interface, the test is executed only if at least one time slot is assigned to the selected port. If no time slot is selected the following message appears:This port is associated with T1E1, but no time slots are assigned to it.

• Local Loopback - Operates identically to other physical ports.• V.54 Loopback 2 - Operates identically to other physical ports but instead of

looping the data trough the local modem connected to the port, the data is looped at the front end of the T1/E1 Interface. Because of hardware limitations, the selected port and all ports associated with the T1E1 interface are looped back. For example, if Ports 7, 8, and 9 are associated with T1E1 interface 1, and an L2 Loop is invoked to test port 7 or 8 or 9, the whole T1 or E1 span is looped during the test. One of the three ports is tested while the other two are disconnected for the duration of the test. The following warning is issued before the test is started:WARNING: Running this test will cause calls on this port and all other ports associated with the same T1/E1 interface to be abnormally disconnected. This operation may result in lost data and disruption of network user services.

• V.54 Loopback 3 - Operates identically to other physical ports but instead of looping the data trough the remote modem connected to the port, the data is looped at the back end of the T1/E1 Remote Interface. This loop is invoked by the remote T1/E1 interface by sending V.54 Loopback 3 or by remote test equipment that can send a V54 Activation Pattern.

TELCO Diagnostics

In North America, the AT&T and ANSI specs determine how the carrier can put the CPE equipment into remote Loopback. The T1 Daughtercard complies with these conditions:

• Line Loopback activated for D4 framing or ESF framing loops the whole span.

• Payload Loopback activated for ESF framing loops the whole span except the FDL channel.



Index

A

Annex D Supportfeature 4, 142

Auto-LearnControl Protocol 56DLCI 57

B

Boot Commanddescription 105, 156FRA Port 156FRA Station 156FRI Port 105FRI Station 105

C

ConfigurationFRI Port Record 8FRI Station Record 151parameters 8, 146physical links 141

Congestion Controlfeature 4

Control ProtocolAuto-Learn 56

CRC Error 159

D

Description of TermsDetailed FRA Port Statistics 163Detailed FRA Station Statistics 168Detailed Frame Relay Port Statistics 112Detailed Frame Relay Station Statistics 120Detailed Link Statistics 127, 146, 171

Detection of Transmission Errorsfeature 142

DLCIAuto-Learn 57parameter 152

E

Enable/DisableFRI Port 108, 160FRI Station 108, 160

Error Messagechanging Highest Station Number 105, 156changing number of SVCs 105, 156

Examine Commanddescription 106, 157FRA Port Record 157, 158FRA Station Record 158FRI Port Record 106, 107FRI Station Record 107

F

FRAconfiguring 145description 1, 141Frame Relay Stations 3, 141hardware requirements 1operation 155Status/Statistics 161

FRA Port Parameters 146, 190FRA Station Parameters

Autocall Mnemonic 152Autocall Timeout 153Billing Records 154Data Link Connection Identifier (DLCI) 152Maximum Number of Autocall Attempts 153Port Number 152Remote Connection ID 153Station Number 152Traffic Priority 153, 191, 192, 200

FRA Stationsdescription 3, 141

Frame Relay Access. See FRAFrame Relay Interface. See FRIFrame Relay Over ISDN 64

Bandwidth on Demand (BoD) 64Dial on Demand (DoD) 64, 66, 68Link Backup 64semi-permanent operation 66, 67Switched Services Table entry 66Vanguard 6520/6560 65Vanguard Configuration Example 69Vanguard Products 65virtual ports 67

Frame Relay Stations. See FRI Stations, FRA Stations

Frame Relay SVCaddressing 79conformance 78examples 86incoming call processing 84introduction 77link integrity 78operation 81outgoing call processing 81port parameter description 79sample configuration 94SNMP support 77

FRF.12definition 182Segmentation 183Voice Header Insertion 185Voice Header Insertion Statistics 126

Index-1

F (Continued)

FRIconfiguring 19description 3features 4Frame Relay Stations 3Status/Statistics 161

FRI Port ParametersControl Protocol Support 11Frame Sequence Counting 10High Priority Station 12Loopback Detection 63Packet Sequence Counting 10

FRI Station ParametersCommitted Burst Size (BC) 27Committed Information Rate (CIR) 26Congestion Control Mode 28, 29CUG Membership 38Data Queue Lower Threshold 34Data Queue Upper Threshold 33Initial Frame 31K Frame Window 32Link Address 29Maximum Information Rate (MIR) 28Number of PVC Channels 29Number of SVC Channels 30P Packet Size 33Port Number 21, 152Restricted Connection Destination 38Starting PVC Channel Number 30Starting SVC Channel Number 30T4 Poll Timer 32W Packet Window 33Window Settings Recommended 41Window Subtractor 40X.25 Options 37

I

ISDN 64

M

Maximum Information Rate (MIR) 47

N

Non-Octet Aligned Error 159

O

On-DemandSVC connections 102X.25 calls 102

P

Port/Station/Channel Control Commanddescription 108, 160enable/disable FRA Port 160enable/disable FRA Station 160enable/disable FRI Port 108enable/disable FRI Station 108

R

Retransmission of Framesfeature 4

S

Same Port Backup 74Status/Statistics Command

description 109, 161Detailed FRA Port Statistics 161Detailed FRA Station Statistics 167Detailed FRI Port Statistics 110Detailed FRI Station Statistics 117Reset FRA Station Statistics 167

SVCFrame Relay 77

SVC Connections On-Demand 102

T

Traffic Shaping 51Example 53

Transmission Fairness 54Example 55

W

Window SettingsAnnex G/X.25 41

Index-2

frame relay

Documents

frame relay services

forms of frame relay

frame relay stations

frame relay networks

frame relay dce ports

frame relay dte ports

frame relay dte interface

frame relay dce service