© Alcatel University - 8AS 90200 0551 VT ZZA Ed.01

9.1

9 Alarm and Error Handling

9.2

9 Alarm and Error Handling Session presentation

Objective: to be able to describe the way the alarms are

managed in an SDH network

program:

9.1 Communication Alarms

9.2 Alarm Indication Signal : AIS

9.3 Remote Defect Indication : RDI

9.4 Alarm and Error Processing within an NE

9.5 Explanation of Alarm and Error Codes

9.6 Alarm and Error Processing

9.7 Performance Monitoring : PM

9.8 Tandem Connections

9.3

9 Alarm and Error Handling Communication Alarms

SDH-Network

ADM

MSN

DXC

ADM

MSN

DXC

Regenerator

ADM

MSN

DXC

PDH

140Mbit/s PDH

2 Mbit/s

9.4

9 Alarm and Error Handling Alarm Indication Signal - AIS

RSOH

1 1

1 1

1

1

1

1

1

1

MS - AIS

AU - AIS

TU – AIS

RSOH

1 1

1

1

1

1

1

1 MSOH

RSOH

MSOH

AU-Pointer P

O

H

1 1 1

1

1

9.5

9 Alarm and Error Handling Remote Defect Indication - RDI

HP-RDI

8 ... 1

1

LP-RDI

8 ... 1

1

MS-RDI

8 ... 1

0 1 1 K2-Byte

G1-Byte

V5-Byte

K2

G1

V5

9.6

9 Alarm and Error Handling Alarm and Error Processing within a NE

LOF

RS-TIM

RS-BIP

MS-AIS

MS-BIP

MS-REI

AU-AIS

AU-LOP

HP-UNEQ

HP-TIM

HP-BIP

HP-REI

HP-RDI

TU-AIS

TU-LOP

TU-LOM

TU-PLM

TU-AIS

TU-AIS

AU-AIS

MS-AIS

C2

H4

G1

G1

B3

J1

C2

K2

M1

B2

K2

B1

J0

A1/A2

LOS

MS-RDI

Detection

Generation

LP-TIM

LP-BIP

LP-REI

LP-RDI PDH-AIS

TU-AIS

V5

V5

V5

V5

J2

V5

LP-PLM

Physical

Section Layer

Regenerator

Section Layer

Multiplex

Section Layer

Higher Order

Path Layer

Lower Order

Path Layer

9.7

9.8

9 Alarm and Error Handling Example Network

SDH-Network

ADM

MSN

DXC

ADM

MSN

DXC

Regenerator

ADM

MSN

DXC

PDH

140Mbit/s PDH

2 Mbit/s

Regenerator Section Regenerator Section

Multiplex Section Multiplex Section

Trail / Path

Regenerator Section

9.9

9 Alarm and Error Handling Alarm and Error Processing in a Regenerator

MS-AIS LOS

LOF

RS-TIM

RS-BIP

MS-AIS

(PM)

RS

1 / M

S1

RS

1

OS

1 / R

S1

OS

1

RS

1 / M

S1

RS

1

OS

1 / R

S1

OS

1

Detection

Generation

RSOH

1 1

1 1

1

1

1

1

1

1

9.10

9 Alarm and Error Handling Alarm and Error Processing in a Multiplexer: VC-4 Passthrough

S4

MS

1 / S

4

MS

1

RS

1 / M

S1

RS

1

OS

1 / R

S1

OS

1

MS

1 / S

4

MS

1

RS

1 / M

S1

RS

1

OS

1 / R

S1

OS

1

LOS

LOF

RS-TIM

RS-BIP

MS-AIS

MS-BIP

MS-REI

MS-RDI

MS-AIS

AU-AIS

(PM)

AU-AIS

(PM)

Detection

Generation

(PM)

RSOH

1 1

1

1

1

1

1

1 MSOH

9.11

9 Alarm and Error Handling Alarm and Error Processing in a Multiplexer: VC-4 Termination

S4

MS

1 / S

4

MS

1

AU-AIS

AU-LOP

HP-UNEQ

HP-TIM

HP-BIP

HP-REI

HP-RDI

AU-AIS

TU-AIS

TU-AIS S

4

TU-AIS

(PM)

Detection

Generation

(PM)

S12

S4 / S

12

RSOH

MSOH

AU-Pointer P

O

H

1 1 1

1

1

9.12

9 Alarm and Error Handling Alarm Processing via a complete Network: Path fault

NE A NE B NE C

NE D

Reg. E Reg. F

LO-passthrough HO-passthrough

LOS

2Mbit/s

9.13

9 Alarm and Error Handling Alarm Processing via a complete Network: Reference fault

NE A NE B NE C

NE D

Reg. E Reg. F

LO-passthrough HO-passthrough

LOS

2Mbit/s

9.14

9 Alarm and Error Handling PM Basics

Error checksum Block size max. number of

block errors per second

B1 (RSOH) STM-N 8.000

B2 (MSOH)

801 bits * N

192.000 * N

(STM-N)

B3 (HP-POH) VC-4

VC-3

8.000

8.000 V5 (LP-POH) VC-12 Multiframe 2.000

9.15

9 Alarm and Error Handling Principles of data collection

Monitored seconds

Defects ?

Anomalies ?

% EB >= 30 ?

cES = cES + 1 cES = cES + 1

cBBE = cBBE + EB(s) cSES = cSES + 1

End

Yes

Yes

Yes

No

No

No

Extracted

from G 826

9.16

9 Alarm and Error Handling Definition of Unavailability

SES

ES which is not a SES

Non errored second

10 sec < 10 sec 10 sec < 10 sec

t in sec

End of detection:

ES := ES + x

SES := SES

UAS := UAS - 10

Begin of detection:

ES := ES - 10

SES := SES - 10

UAS := UAS + 10

Unavailable Time (UAT)

Inhibition of counters:

ES / SES / (BBE)

Available Time

x

9.17

9 Alarm and Error Handling Near End / Far End counters

NE A

STM-N with errors

Far End Counters:

FEBBE

FEES

FESES

FEUAS

Near End Counters:

BBE

ES

SES

UAS

STM-N with REI

NE B

9.18

9 Alarm and Error Handling Why Tandem Connections

[total biterrors]

Path

Sink

Path

Source

Near end bit errors counted by path monitor (PM) [location]

Bit errors added before domain 1

Bit errors added in domain 1

Bit errors added between domain 1 and domain 2

Bit errors added in

domain 2

Domain 1 Domain 2

VCn-Path

Inter Domain

Link

9.19

9 Alarm and Error Handling Function of Tandem Connections

VCn-Path

Near end bit errors counted by Tandem Connections (TC)

sk so

TC 1

so sk

TC 12

Path

Sink

Path

Source

Domain 1 Domain 2 Inter Domain

Link

sk so

TC 2

so: source

sk: sink

[location]

[total biterrors]

9.20

9 Alarm and Error Handling Overhead Bytes used for Tandem Connections

REI OEI

Payload

G1

F2

H4

F3

K3

N1

C2

B3

J1

Virtual Container (VC-4, VC-3)

Number of bit errors detected by

TC source

frame 1-8: FAS

frame 9-72: 64*2 Bit= 16Byte TC-TI

frame 73: TC-RDI

frame 74: ODI

frame 75,76: all ‘0’

N1 used for TCs

1 2 3 4 5 7 8 6

9.21

9 Alarm and Error Handling Tandem Connection Termination: TCT

SDH port SDH port

Path

Path

Domain 1

N1=0

N1=0

N1=0

N1=0

BBE = 2

N1:=2

NE 1

SPI

RST

MST

MSA

BBE = 6

N1 = 2

NE_BBE := 6 - 2 =4

NE x

TC 1 (Egressing Tandem Connection)

TC after

Matrix

TC after

Matrix

SPI

RST

MST

MSA

SPI

RST

MST

MSA

SPI

RST

MST

MSA

9.22

9 Alarm and Error Handling Tandem Connection Monitoring: TCM

SPI

RST

MST

MSA Path

SDH Port

TCm

RX

Before Matrix

TC

SDH Port

TCm

TX

After Matrix

SPI

RST

MST

MSA

9.23

Thank you for answering

the self-assessment

of the objectives sheet

9 Alarm and Error Handling Evaluation

Objective: to be able to describe the

way the alarms are managed in an

SDH network