application note: 8635 conﬁguration for...

Application Note

WEBSITE: www.jdsu.com

The purpose of this document is to provide information regarding the configuration of the 8635 Telecom Proto-col Analyzer for an UMTS capture.

UMTS network architecture This document discusses the configuration of the 8635 in order to monitor Iub and Iu (Iu-PS and Iu-CS) inter-faces of a UMTS network. Figure 1 shows a schematic diagram of a typical UMTS network architecture.

Figure 1. A schematic diagram of a UMTS network architecture

The dedicated signaling and traffic on the Iub interface is ciphered. In order to use the call trace and call detailed record (CDR) features on the Iub interface, the dedicated channels must be deciphered.To decipher these channels, the 8635 requires information from the Iu interface (deciphering keys). Therefore, in order to monitor and decipher the Iub interface, the corresponding Iu interface must also be monitored. In most cases, the Iu and Iub interfaces are on different fibers. For instance on one measurement card, interface A of the 8635 can be used to monitor the Iu interface, and interface B of the 8635 can be used to monitor the Iub inter-face. In some cases, the Iu and Iub interfaces are on the same fiber.

External tools

ATM Discovery Application When connected to a system, it is often difficult to determine which fiber contains the Iu and Iub interfaces. For this reason, the 8635 provides the user with ATM Discovery, a tool that analyzes the ATM traffic. Versions V3.73.0.0 and newer offer this useful tool on the launch pad (figure 2). The ATM Discovery application program is located in the 8635 installation directory (C:\Program Files\Acterna\Acterna 8635\analyzer\appls).

8635 Configuration for 3G/UMTSBy bitGate

MSC

RNC

RNC

NodeB

NodeB

NodeBSGSN

Uu

Iub

Iu-PS

Iu-CS

Iur

Radio interface Radio access network Core network

Application Note: 8635 Configuration for 3G/UMTS 2

Figure 2. The launch pad of the 8635 showing the ATM Discovery application shortcut

To analyze the traffic, launch ATM Discovery. To start the ATM Discovery application, click on the red record icon. Upon launching the ATM Discovery application, two windows will open.

Card overview This window displays all the ports (VPs) that can be captured by the card and provides basic information about the traffic load on each VP (figure 3).

Card details When one bar (VP) in the summary window is clicked on, a list of VCs is dis-played for the corresponding VP (figure 4).

Both windows can be displayed at the same time by dragging the window tab to the desktop.

Figure 3. An example Card Overview window using the ATM Discovery application


Figure 4. An example Card Details window using the ATM Discovery application

Using the ATM Discovery application, the channels (VP) that are carrying traffic are identified. The Iu interface should reflect a higher data rate.

Typical configurations seen at operators for certain infrastructure :

VCs on a VP Interface34,35,40,41 Iu Siemens 34,35,65,66 Iub Siemens 36,37,38,39,43,44,45 Iub Ericsson 33,34,35,40,41,42,46 Iub Nokia


Configuring the 8635During the configuration process, the use of logical interfaces is recommended in order to maintain a logical view of your system. For example :One logical interface for Iu-CSOne logical interface for Iu-PSOne logical interface per Node B.For Iub configuration, three levels can be distinguished using the configuration tool :• Channel level configuration: One channel is configured for both directions.• NodeB level configuration: All channels belonging to one NodeB are configured.• System level configuration: A set of NodeBs is configured.System level configuration is based on NodeB level configuration, and NodeB level configuration is based on channel level configuration.For Iu configuration, only channel level configuration is available.

Channel-level configuration

Creating a logical interfaceThe creation of a logical interface provides two key advantages :• It helps maintain a logical view of your system.• It increases system performance by hardware filtering all unused VPs/VCs.By default, when a logical interface is not defined, all VPs/VCs are discarded by the analyzer.On the other hand, when a logical interface is created, a list of VP/VC pairs corresponding to this logical interface is defined. All of these VP/VC pairs are then enabled in the analyzer for data capture.

Figure 5. IuB interface configuration


Iu configurationThe Iu interface contains only AAL-5 channels. There are three steps involved in configuring each AAL-5 chan-nel.• Check same settings for Rx1 and Rx2.• Select the Iu_ALCAP_RANAP_R??_nrf protocol stack corresponding to the protocol release of the net-

work.Note: For each protocol release, two protocol stacks may be included – one with an _nrf extension and one

without. The _nrf extension refers to “no recording filter”. This protocol stack is used when capture filters are not required. The advantage of using the _nrf protocol stack is that it loads much faster when the data recorder is started. Therefore, we strongly recommend using the _nrf protocol stack if possible!

• Set the channel’s VP/VC pair.

Iub configurationThe Iub interface is more difficult to configure. For Iub configuration, the following channels must be config-ured:Channel Description Protocol stack AAL typeALCAP AAL-2 connection management Iub_TCP_ALCAP AAL-5NBAP Node B application part signaling (management of

the nodeB by the RNC)Iub_NBAP_R?? AAL-5

PCH Paging channel Iub_RRC_R?? AAL-2FACH Forward access channel (common downlink transport

channel)Iub_RRC_R?? AAL-2

RACH Random access channel (common uplink transport channel)

Iub_RRC_R?? AAL-2

DCCH Dedicated signaling transport channel Iub_RRC_R?? AAL-2DTCH Dedicated IP traffic transport channel Iub_DTCH_IP_R?? AAL-2DTCH Dedicated voice traffic transport channel To be defined AAL-2

Note: On some systems, there may be more than one PCH, FACH, RACH channel for each NodeB.To configure the AAL-5 channels, perform the following steps in the source configuration: • Check “same settings” for Rx1 and Rx2. (Question: what does it mean: Click on the check box for “Settings

are the same for Rx1 and Rx2”.)• Select the protocol stack corresponding to the protocol release of the network.• Set the channel’s VP/VC pair.There are more steps necessary to configure the AAL-2 channels. Each AAL-2 channel is characterized by a VP/VC/CiD combination. “CiD” refers to the connection identifier and has values between 0 and 255.On some system, the CiD values are known and are static for the common transport channels. On other systems, Ericsson’s system for example, the CiD values for the common transport channels are dynamic and can change when the nodeB is reconfigured or restarted.For this reason, the 8635 uses a specific algorithm that can automatically detect the type of transport channel (FACH, RACH, PCH, or DxCH) and the corresponding CiD. This algorithm allows the 8635 to continue to monitor/record a nodeB when it’s reconfigured without requiring any user reconfiguration steps. To enable this algorithm enter “auto” in the CiD configuration field instead of a value between 0 and 255.Note: For systems using static CiD values, it is more advantageous to set the actual CiD values instead of enter-

ing “auto” due to better system performance.


Step by step configuration of AAL-2 channels • Check “same settings” for Rx1 and Rx2.• Select the protocol stack corresponding to the protocol release of the network.• Set channel VP/VC/CiD combination For the common transport channels (FACH, RACH, and PCH), set

the CiD values if they are static. If the CiD values are dynamic, set them to “auto”.• Set the transport channel type (PCH, RACH, FACH, or DxCH)• Set the transport format Set (TFS). The TFS table is used to decode the FP and must be configured by the

user. Each entry in the table is a pair of data, including number of transport blocs and transport bloc size. The file names for several default TFS tables are available in Appendix A. If none of the default TFS tables matches your specific configuration, you can create your own, save it, and reuse it later.Note: When at least two entries contain the same transport bloc size (1 × 336, 2 × 336, for example), the 8635

assumes an n × transport bloc size (n × 336). This feature is especially useful in the configuration of DTCH IP traffic.

• Map the logical channels on the transport channel. The default logical channel settings should be used, if possible (Appendix A). If your configuration is not available in Appendix A, you can create your own con-figuration and save it for later use.Note: If you want to capture DCCH/DTCH on FACH/RACH, for example, then add the DCCH and DTCH

logical channels on the FACH/RACH transport channel. Since the logical channel identifier (C/T) for DTCH is dynamic, you need to add all of the logical channel identifiers except DCCH.

• Set the FP synchronization filters to suppress these messages. You should get this filter by default.


Note: Decoding the Iub interface depends on the direction of the traffic! Therefore, verify that the direction information for the physical interface is correct. Otherwise, the decoding will fail. The direction of the traffic can be verified by analyzing the direction information provided in the NBAP CommonMea-surementReport message:

1 NBAP_1B-01-02 64 35 0 SCMD IM CommonMeasurementReport cell measurement Available 11:59:10.945

******** 3G Acterna

******** ATM

******** ATM virtual path : 64

******** ATM virtual channel : 35

00000000 ATM/AAL2 connection : 0

******** Proprietary Information

******** Settings

0------- NFO_FLAG : 0b

******** DSP_ERROR_INFO

-000---- TYPE : 000b = No Error

----0000 RFU : 0000b

0------- AAL2_RAW_FLAG : 0b

******** RFU : 000000000b

--0010-- Protocol : 0010b = SSCOP

------0- Direction : 0b = Uplink

-------0 Configuration : 0b = FDD

******** Service Specific Connection Oriented Protocol

******** <General Fields>

******** <Sequence Number or RFU> : 772446

00001000 <PL/R/S bit and PDU Type> : 8h = Sequenced Connection-mode Data

******** SEQUENCED CONNECTION-MODE DATA

******** Information : 00 08 4A 34 55 12 00 00 02 00 85 40 03 40 03 D7

: 00 1F 40 04 00 10 00 32h

******** Padding length : 0b

******** Reserved for used : 0b

******** PDU type : 1000b = Sequenced Connection-mode Data

******** NBAP-PDU

******** initiatingMessage

******** procedureID

00001000 procedureCode : 8

-10----- ddMode : 2 = common

---01--- criticality : 1 = ignore

-----0-- messageDiscriminator : 0 = common

******** transactionID

******** longTransActionId : 13397

******** value : 12 00 00 02 00 85 40 03 40 03 D7 00 1F 40 04 00

: 10 00 32h

******** CommonMeasurementReport

If the direction information, as displayed above, is not decoded as “UPLINK”, than the direction setting is incorrect. In this case , switch the fiber setting from RX1 to RX2, or physically change the fiber on the mea-surement card and restart the 8635 software!!


NodeB-level configurationIn order to simplify the configuration of the Iub interface, a NodeB configuration wizard is provided. To activate the wizard, select a physical interface in the configuration tool and select NodeB-Channel Wizard (figure 6).

Figure 6. Using the NodeB-Channel Wizard

Selected default vendor configuration information is provided, but user-specific settings can also be entered and saved.When the configuration is ready, the only additional parameter required is the VP. The NodeB-Channel Wizard then creates a logical interface for this NodeB and all of the channels belonging to the NodeB.The NodeB-Wizard uses the TFS configuration files and the mapped logical channel files that were defined at the channel configuration level (figure 7). The auto-detection check box allows for the use of the auto-detection algorithm in the DSP, automatically detecting the transport channels.


Figure 7. Using the NodeB-Wizard

System-LevelConfigurationThe NodeBListManager application tool is used to build a list of NodeBs which will be configured. When the list is built, it can be added to the configuration context menu using “Load NodeB List”. The NodeB List Manager application program is located in the 835 installation directory (C:\Program Files\Acterna\Acterna 8635\ana-lyzer\appls). This tool helps to build the XML file used by the configuration tool to configure a set of NodeBs.For each NodeB entry in the table, a logical interface is created (figure 8). Each logical interface is named by the user, providing them with a clear overview of the system in the configuration tool. The wizard filename is the NodeB-Channel Wizard filename, and the VPs and VCs are identified for each logical interface file. The file is in an XML format (Appendix B). Therefore, users can also create their own tool to build the list.

Figure 8. Using the NodeB List Manager application tool

All statements, technical information and recommendations related to the products herein are based upon informa-tion believed to be reliable or accurate. However, the accuracy or completeness thereof is not guaranteed, and no responsibility is assumed for any inaccuracies. The user assumes all risks and liability whatsoever in connection with the use of a product or its applications. JDSU reserves the right to change at any time without notice the design, speci-fications, function, fit or form of its products described herein, including withdrawal at any time of a product offered for sale herein. JDSU makes no representations that the products herein are free from any intellectual property claims of others. Please contact JDSU for more information. JDSU and the JDSU logo are trademarks of JDS Uniphase Corporation. Other trademarks are the property of their respective holders. © 2006 JDS Uniphase Corporation. All rights reserved. 30137488 000 0506 CONFIG8635.AN.CPO.TM.AE

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White Paper: 8635 Configuration for 3G/UMTS 10

Appendix A

TFS TablesFile name ContentsFACH.tfs Transport format set for FACHRACH.tfs Transport format set for RACHPCH.tfs Transport format set for PCHPCH_Nokia.tfs Transport format set for PCH on NOKIA systemsDCH_DCCH.tfs Transport format set for DCCHDCH_DTCH_IP.tfs Transport format set for DTCH IP traffic

Default logical channel settings File name ContentsDCCHuBCCHuCCCHonFACH.mlc DCCH and BCCH and CCCH on FACHDCCHuBCCHuCCCHonFACH_siemens.mlc DCCH and BCCH and CCCH on FACH for Siemens

systemsDCCHuCCCH_RACH.mlc DCCH and CCCH on RACHDCCHuCCCH_RACH_siemens.mlc DCCH and CCCH on RACH for Siemens systemDTCH_for_IP_Payload.mlc DTCH for IP payloadDTCHuDCCHuBCCHuCCCHonFACH.mlc DTCH and DCCH and BCCH and CCCH on FACH DTCHuDCCHuBCCHuCCCHonFACH_siemens.mlc DTCH and DCCH and BCCH and CCCH on FACH for

Siemens SystemsDTCHuDCCHuCCCH_RACH.mlc DTCH and DCCH and CCCH on RACHDTCHuDCCHuCCCH_RACH_siemens.mlc DTCH and DCCH and CCCH on RACH for Siemens

Systems

Default vendor NodeB configurationsFile name ContentsEricsson.iwz Ericsson default NodeB config Ericson_with_ip_traffic.iwz Ericsson default NodeB config with IP traffic captureLucent_R5.iwz Lucent default NodeB configNokia.iwz Nokia default NodeB configNokia_with_ip_traffic.iwz Nokia default NodeB config with IP traffic captureSiemens.iwz Siemens default NodeB configSiemens_with_ip_traffic.iwz Siemens default NodeB config with IP traffic capture

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