31030386 Maintenance Manual

1 Maintenance Precautions and Basic Operations 1-1......................................1.1 Maintenance Precautions 1-1.......................................................................

1.1.1 Laser 1-1..............................................................................................1.1.2 Electrical Safety 1-3.............................................................................1.1.3 Board Mechanical Safety 1-4...............................................................1.1.4 Network Management System Maintenance 1-5.................................1.1.5 Modifying Traffic Configuration 1-5......................................................

1.2 Basic Operations 1-6....................................................................................1.2.1 Swapping Fiber Jumper 1-6.................................................................1.2.2 Swapping Board 1-6.............................................................................1.2.3 Resetting SCC Unit 1-9........................................................................1.2.4 Testing Trunk Cable with Multimeter 1-9.............................................1.2.5 Loopback Operation 1-9.......................................................................1.2.6 Bit Error Test 1-14..................................................................................1.2.7 Cable Tag Description 1-15...................................................................1.2.8 Receiving/transmitting Optical Power Test 1-18....................................1.2.9 Preparation of the Ethernet Cable of NMS Computer 1-19....................

2 Routine Maintenance 2-1....................................................................................

2.1 Maintenance Overview 2-1...........................................................................2.1.1 Maintenance Objective 2-1..................................................................2.1.2 Classification of Maintenance 2-1........................................................2.1.3 Basic Principles for Routine Maintenance 2-2.....................................2.1.4 Maintenance Capability of OptiX Metro 500 Equipment 2-2................

2.2 Routine Maintenance Items of Equipment 2-4.............................................2.2.1 Observing Indicators 2-5......................................................................2.2.2 Checking Equipment Temperature 2-5................................................2.2.3 Service Check -- Bit Error Test 2-6......................................................

2.3 Routine Maintenance Items of NMS 2-7.......................................................3 Principle for Generation of Alarm and Performance Event 3-1......................

3.1 Overview of SDH Alarm and Performance Event 3-1...................................3.1.1 Terminology Agreement 3-3.................................................................3.1.2 Two Common Alarms 3-3....................................................................

3.2 Generation and Detection of Alarm and Performance Event inSignal Flow of Higher Order Part 3-4.................................................................

3.2.1 Downlink Signal Flow 3-5.....................................................................3.2.2 Uplink Signal Flow 3-8.........................................................................

3.3 Generation of Alarm and Performance in Signal Flow of LowerOrder Part 3-10.....................................................................................................

3.3.1 Downlink Signal Flow 3-11.....................................................................

3.3.2 Uplink Signal Flow 3-12.........................................................................3.4 SDH Alarm Suppression 3-14........................................................................3.5 Generation and Detection of SDH Performance Event 3-16..........................

3.5.1 Bit Error 3-16..........................................................................................3.5.2 Pointer Justification 3-19........................................................................

3.6 Application of Locating a Fault According to Signal Flow 3-22.......................3.6.1 Bit Error 3-22..........................................................................................3.6.2 Alarm 3-23..............................................................................................3.6.3 Summary 3-24........................................................................................3.6.4 Method of Analyzing Alarms and Faults 3-24........................................

4 Alarm and Performance Event Handling 4-1....................................................Alarm Handing 4-1..............................................................................................AU_AIS 4-2.........................................................................................................AU_LOP 4-3.......................................................................................................B1_EXC 4-4........................................................................................................B1_SD 4-5..........................................................................................................B2_EXC 4-6........................................................................................................B2_SD 4-7..........................................................................................................B3_EXC 4-8........................................................................................................B3_SD 4-9..........................................................................................................BIP_EXC 4-10......................................................................................................BIP_SD 4-11.........................................................................................................BUS_LOC 4-12.....................................................................................................DOWN_E1_AIS 4-13............................................................................................E1_LOS 4-14........................................................................................................FAN_FAIL 4-15.....................................................................................................HP_LOM 4-16.......................................................................................................HP_RDI 4-17........................................................................................................HP_REI 4-18........................................................................................................HP_SLM 4-19.......................................................................................................HP_TIM 4-20........................................................................................................HP_UNEQ 4-21....................................................................................................J0_MM 4-22..........................................................................................................LOOP_ALM 4-23..................................................................................................LP_RDI 4-24.........................................................................................................LP_REI 4-25.........................................................................................................LP_RFI 4-26.........................................................................................................LP_R_FIFO 4-27..................................................................................................LP_SIZE_ERR 4-28.............................................................................................LP_SLM 4-29........................................................................................................

LP_T_FIFO 4-30...................................................................................................LP_TIM 4-31.........................................................................................................LP_UNEQ 4-32.....................................................................................................LTI 4-33................................................................................................................MS_AIS 4-34........................................................................................................MS_RDI 4-35........................................................................................................MS_REI 4-36........................................................................................................NESTATE_INSTALL 4-37....................................................................................POWER_FAIL 4-38..............................................................................................PS 4-39.................................................................................................................PWR_MAJ_ALM 4-40..........................................................................................R_LOF 4-41..........................................................................................................R_LOS 4-42..........................................................................................................R_OOF 4-43.........................................................................................................RP_LOC 4-44.......................................................................................................SYN_BAD 4-45.....................................................................................................SYNC_C_LOS 4-46..............................................................................................T_ALOS 4-47........................................................................................................T_LOC 4-48..........................................................................................................T_LOS 4-49..........................................................................................................T_LOTC 4-50........................................................................................................TU_AIS 4-51.........................................................................................................TU_LOP 4-52.......................................................................................................W_R_FAILURE 4-53............................................................................................WRG_BD_TYPE 4-54..........................................................................................Performance Events of SDH Service 4-55...........................................................AUPJCHIGH 4-58.................................................................................................AUPJCLOW 4-59.................................................................................................TUNPJC 4-60.......................................................................................................TUPPJC 4-61.......................................................................................................HPBBE 4-62.........................................................................................................HPCSES 4-63.......................................................................................................HPES 4-64............................................................................................................HPFEBBE 4-65.....................................................................................................HPFEES 4-66.......................................................................................................HPFESES 4-67.....................................................................................................HPSES 4-68.........................................................................................................HPUAS 4-69.........................................................................................................LPBBE 4-70..........................................................................................................LPCSES 4-71.......................................................................................................LPES 4-72............................................................................................................

LPFEBBE 4-73.....................................................................................................LPFECSES 4-74...................................................................................................LPFEES 4-75........................................................................................................LPFESES 4-76.....................................................................................................LPSES 4-77..........................................................................................................LPUAS 4-78..........................................................................................................MSBBE 4-79.........................................................................................................MSCSES 4-80......................................................................................................MSES 4-81...........................................................................................................MSFEBBE 4-82....................................................................................................MSFECSES 4-83..................................................................................................MSFEES 4-84.......................................................................................................MSFESES 4-85....................................................................................................MSSES 4-86.........................................................................................................MSUAS 4-87.........................................................................................................RSBBE 4-88.........................................................................................................RSCSES 4-89.......................................................................................................RSES 4-90............................................................................................................RSOFS 4-91.........................................................................................................RSOOF 4-92.........................................................................................................RSSES 4-93.........................................................................................................RSUAS 4-94.........................................................................................................

5 Basic Thoughts and Methods for Fault Locating 5-1......................................5.1 Requirements for Maintenance Staff 5-1......................................................

5.1.1 Professional Skills 5-1..........................................................................5.1.2 Aware of Network Layout 5-3...............................................................5.1.3 Collecting and Storing On-site Data 5-3...............................................

5.2 Basic Principles of Fault Locating 5-4..........................................................5.2.1 External First, then Transmission 5-4..................................................5.2.2 Network First, then NE 5-4...................................................................5.2.3 High-speed Section First, then Low-speed One 5-4............................5.2.4 Higher Order Alarms First, then Lower Order Alarms 5-4....................

5.3 Common Methods of Fault Locating 5-5......................................................5.3.1 Alarm and Performance Analysis 5-6...................................................5.3.2 Loopback 5-9.......................................................................................5.3.3 Replacement 5-15..................................................................................5.3.4 Configuration Data Analysis 5-16...........................................................5.3.5 Configuration Modification 5-17.............................................................5.3.6 Meter Test 5-18......................................................................................5.3.7 Experience 5-18.....................................................................................

5.3.8 Comparison of Fault Locating Methods 5-19.........................................5.4 Some Classified Fauts & their Troubleshooting 5-20.....................................

5.4.1 External Faults Handling 5-20................................................................5.4.2 Localizing Fault to a Single Station 5-22................................................5.4.3 Localizing Fault to the Boards 5-23........................................................

5.5 Conact Huawei for Assistance 5-24...............................................................5.6 Obtaining the Latest Technical Documentation 5-25......................................

A Abbreviations A-1...............................................................................................

HUAWEI

OptiX Metro 500 Ultra Compact STM-1 Multi-Service Transmission Platform Maintenance Manual

V100R001

OptiX Metro 500 Ultra Compact STM-1

Multi-Service Transmission Platform

Maintenance Manual

Manual Version T2-040386-20030425-C-1.10

Product Version V100R001

BOM 31030386

Huawei Technologies Co., Ltd. provides customers with comprehensive technical support and service. Please feel free to contact our local office, customer care center or company headquarters.

Huawei Technologies Co., Ltd.

Address: Administration Building, Huawei Technologies Co., Ltd.,

Bantian, Longgang District, Shenzhen, P. R. China

Postal Code: 518129

Website: http://www.huawei.com

Email: [email protected]

Copyright 2003 Huawei Technologies Co., Ltd.

All Rights Reserved

No part of this manual may be reproduced or transmitted in any form or by any means without prior written consent of Huawei Technologies Co., Ltd.

Trademarks

, HUAWEI, C&C08, EAST8000, HONET, , ViewPoint, INtess, ETS, DMC,

TELLIN, InfoLink, Netkey, Quidway, SYNLOCK, Radium, M900/M1800, TELESIGHT, Quidview, Musa, Airbridge, Tellwin, Inmedia, VRP, DOPRA, iTELLIN, HUAWEI OptiX, C&C08 iNET, NETENGINE, OptiX, SoftX, iSite, U-SYS, iMUSE, OpenEye, Lansway, SmartAX are trademarks of Huawei Technologies Co., Ltd.

All other trademarks mentioned in this manual are the property of their respective holders.

Notice

The information in this manual is subject to change without notice. Every effort has been made in the preparation of this manual to ensure accuracy of the contents, but all statements, information, and recommendations in this manual do not constitute the warranty of any kind, express or implied.

OptiX Metro 500 MM

1 About This Manual

Release Notes

This document is for OptiX Metro 500 Ultra Compact STM-1 Multi-service Optical Transmission Platform, Version V100R001.

Related Documentation

The documentation portfolio is divided into:

Documentation for the optical network products

Documentation for the network management (NM) systems

The documentation package for an optical network product is shipped with the product, and the documentation package for an NM system is shipped with the NM system. The table below lists the documentation for the products.

About This Manual OptiX Metro 500 MM

Documentation shipped with the product Document Usage OptiX Metro 500 Ultra Compact STM-1 Multi-service Optical Transmission Platform Technical Manual

Introduces the functionality, structure, performance, specifications, and theory of the product.

OptiX Metro 500 Ultra Compact STM-1 Multi-service Optical Transmission Platform Hardware Description Manual

Introduces the hardware of the product, including cabinet, subrack, power, fan, board, and a variety of interfaces.

OptiX Metro 500 Ultra Compact STM-1 Multi-service Optical Transmission Platform Installation Manual

Guides the on-site installation of the product and provides the information of the structural parts.

OptiX Metro 500 Ultra Compact STM-1 Multi-service Optical Transmission Platform Maintenance Manual

Guides the analysis and troubleshooting of common faults.

Documentation shipped with the NM system

Document Volume Usage

OptiX iManager T2000 Integration Network Management System for Transmission Network(Sub-Network Level) Technical Manual

Introduces the position, software and hardware structure, functionality features, networking mode and performance specifications of the T2000, appended with standards that the T2000 complies with, abbreviations, tables of functions and alarm & performance.

Configuration OptiX iManager T2000 Integration Network Management System for Transmission Network(Sub-Network Level) Operation Manual

Management & Maintenance

Introduces the operation tasks of T2000, including provisioning, maintenance, and task management.

OptiX iManager T2000 Integration Network Management System for Transmission Network(Sub-Network Level) Installation Manual

Introduces the installation procedures of the T2000 under the UNIX and Windows 2000 platform, and the installation procedures of T2000-LCT. The installation of the Solaris 8 operating environment is described as well.

OptiX iManager T2000 Integration Network Management System for Transmission Network(Sub-Network Level) Electronic Documentation (CD)

Contains all the above manuals in CD format, readable with Acrobat Reader.


Organization

The document has the following organization:

Chapter Description

Chapter 1 Maintenance Precautions and Basic Operations

Describes maintenance precautions and basic operations which maintenance personnel should master for the OptiX Metro 500 maintenance.

Chapter 2 Routine Maintenance

Describes maintenance objective and methods in routine maintenance of the OptiX Metro 500.

Chapter 3 Principle for Generation of Alarm and Performance Event

Details the generation principles of various alarms and performance events and their relations. This chapter is the basis for you to apply alarm and performance analysis in troubleshooting.

Chapter 4 Alarm and Performance Event Handling

Lists common alarms. You can find common alarms, causes, and treatments in this chapter.

Chapter 5 Basic Thoughts and Methods for Fault Locating

Describes the operation of troubleshooting and the common methods used in respective procedures. Meanwhile, it emphasizes the thought for the troubleshooting locating the fault to a single station.

Appendix A Abbreviations Lists the full names of all the abbreviations in this manual

Intended Audience

This document is for:

Network administrator

Maintenance engineer

Provisioning engineer


Conventions

The following conventions are used throughout this publication. Symbol Description

Means reader be careful. In this situation, you might do something that could result in equipment damage or loss of data.

Means reader be careful. The equipment is static-sensitive.

Means reader be careful. In this situation, the high voltage could result in harm to yourself or others.

Means reader be careful. In this situation, the strong laser beam could result in harm to yourself or others.

Means reader take note. Notes contain helpful suggestions or useful background information.

Release Upgrade Description

Release Release upgrade description

T2-040386-20030425-C-1.10 This document is the first release.

OptiX Metro 500 MM

i

Contents

1 Maintenance Precautions and Basic Operations

1.1 Maintenance Precautions 1-1 1.1.1 Laser 1-1 1.1.2 Electrical Safety 1-3 1.1.3 Board Mechanical Safety 1-4 1.1.4 Network Management System Maintenance 1-5 1.1.5 Modifying Traffic Configuration 1-5

1.2 Basic Operations 1-6 1.2.1 Swapping Fiber Jumper 1-6 1.2.2 Swapping Board 1-6 1.2.3 Resetting SCC Unit 1-9 1.2.4 Testing Trunk Cable with Multimeter 1-9 1.2.5 Loopback Operation 1-9 1.2.6 Bit Error Test 1-14 1.2.7 Cable Tag Description 1-15 1.2.8 Receiving/transmitting Optical Power Test 1-18 1.2.9 Preparation of the Ethernet Cable of NMS Computer 1-19

2 Routine Maintenance

2.1 Maintenance Overview 2-1 2.1.1 Maintenance Objective 2-1 2.1.2 Classification of Maintenance 2-1 2.1.3 Basic Principles for Routine Maintenance 2-2 2.1.4 Maintenance Capability of OptiX Metro 500 Equipment 2-2

2.2 Routine Maintenance Items of Equipment 2-4 2.2.1 Observing Indicators 2-5 2.2.2 Checking Equipment Temperature 2-5 2.2.3 Service Check -- Bit Error Test 2-6

OptiX Metro 500 MM

ii

Contents

2.3 Routine Maintenance Items of NMS 2-7

3 Principle for Generation of Alarm and Performance Event

3.1 Overview of SDH Alarm and Performance Event 3-1 3.1.1 Terminology Agreement 3-3 3.1.2 Two Common Alarms 3-3

3.2 Generation and Detection of Alarm and Performance Event in Signal Flow of Higher Order Part 3-4

3.2.1 Downlink Signal Flow 3-5 3.2.2 Uplink Signal Flow 3-8

3.3 Generation of Alarm and Performance in Signal Flow of Lower Order Part 3-10

3.3.1 Downlink Signal Flow 3-11 3.3.2 Uplink Signal Flow 3-12

3.4 SDH Alarm Suppression 3-14 3.5 Generation and Detection of SDH Performance Event 3-16

3.5.1 Bit Error 3-16 3.5.2 Pointer Justification 3-19

3.6 Application of Locating a Fault According to Signal Flow 3-22 3.6.1 Bit Error 3-22 3.6.2 Alarm 3-23 3.6.3 Summary 3-24 3.6.4 Method of Analyzing Alarms and Faults 3-24

4 Alarm and Performance Event Handling

Alarm Handing 4-1 AU_AIS 4-2 AU_LOP 4-3 B1_EXC 4-4 B1_SD 4-5

OptiX Metro 500 MM

iii

Contents

B2_EXC 4-6 B2_SD 4-7 B3_EXC 4-8 B3_SD 4-9 BIP_EXC 4-10 BIP_SD 4-11 BUS_LOC 4-12 DOWN_E1_AIS 4-13 E1_LOS 4-14 FAN_FAIL 4-15 HP_LOM 4-16 HP_RDI 4-17 HP_REI 4-18 HP_SLM 4-19 HP_TIM 4-20 HP_UNEQ 4-21 J0_MM 4-22 LOOP_ALM 4-23 LP_RDI 4-24 LP_REI 4-25 LP_RFI 4-26 LP_R_FIFO 4-27 LP_SIZE_ERR 4-28 LP_SLM 4-29 LP_T_FIFO 4-30 LP_TIM 4-31 LP_UNEQ 4-32 LTI 4-33 MS_AIS 4-34 MS_RDI 4-35 MS_REI 4-36 NESTATE_INSTALL 4-37 POWER_FAIL 4-38

OptiX Metro 500 MM

iv

Contents

PS 4-39 PWR_MAJ_ALM 4-40 R_LOF 4-41 R_LOS 4-42 R_OOF 4-43 RP_LOC 4-44 SYN_BAD 4-45 SYNC_C_LOS 4-46 T_ALOS 4-47 T_LOC 4-48 T_LOS 4-49 T_LOTC 4-50 TU_AIS 4-51 TU_LOP 4-52 W_R_FAILURE 4-53 WRG_BD_TYPE 4-54 Performance Events of SDH Service 4-55 AUPJCHIGH 4-57 AUPJCLOW 4-58 TUNPJC 4-59 TUPPJC 4-60 HPBBE 4-61 HPCSES 4-62 HPES 4-63 HPFEBBE 4-64 HPFEES 4-65 HPFESES 4-66 HPSES 4-67 HPUAS 4-68 LPBBE 4-69 LPCSES 4-70 LPES 4-71 LPFEBBE 4-72

OptiX Metro 500 MM

v

Contents

LPFECSES 4-73 LPFEES 4-74 LPFESES 4-75 LPSES 4-76 LPUAS 4-77 MSBBE 4-78 MSCSES 4-79 MSES 4-80 MSFEBBE 4-81 MSFECSES 4-82 MSFEES 4-83 MSFESES 4-84 MSSES 4-85 MSUAS 4-86 RSBBE 4-87 RSCSES 4-88 RSES 4-89 RSOFS 4-90 RSOOF 4-91 RSSES 4-92 RSUAS 4-93

5 Basic Thoughts and Methods for Fault Locating

5.1 Requirements for Maintenance Staff 5-1 5.1.1 Professional Skills 5-1 5.1.2 Aware of Network Layout 5-3 5.1.3 Collecting and Storing On-site Data 5-3

5.2 Basic Principles of Fault Locating 5-4 5.2.1 External First, then Transmission 5-4 5.2.2 Network First, then NE 5-4 5.2.3 High-speed Section First, then Low-speed One 5-4

OptiX Metro 500 MM

vi

Contents

5.2.4 Higher Order Alarms First, then Lower Order Alarms 5-4

5.3 Common Methods of Fault Locating 5-5 5.3.1 Alarm and Performance Analysis 5-6 5.3.2 Loopback 5-9 5.3.3 Replacement 5-15 5.3.4 Configuration Data Analysis 5-16 5.3.5 Configuration Modification 5-17 5.3.6 Meter Test 5-18 5.3.7 Experience 5-18 5.3.8 Comparison of Fault Locating Methods 5-19

5.4 Some Classified Fauts & their Troubleshooting 5-20 5.4.1 External Faults Handling 5-20 5.4.2 Localizing Fault to a Single Station 5-22 5.4.3 Localizing Fault to the Boards 5-23

5.5 Conact Huawei for Assistance 5-24 5.6 Obtaining the Latest Technical Documentation 5-25

A Abbreviations

A

OptiX Metro 500 MM

1-1

1 Maintenance Precautions and

Basic Operations

1.1 Maintenance Precautions

To ensure the safety of the maintenance personnel and that of the equipment, some basic rules must be followed before equipment maintenance.

1.1.1 Laser

Warning:

The laser emitted by the optical interface board is invisible infrared ray, which may cause permanent damage to human eyes.

When operating the optical connectors of the fiber jumper and optical interface board, please wear a pair of protective glasses that can filter infrared ray to avoid the damage to your eyes. It is forbidden to directly stare into the laser aperture and fiber connectors on the optical interface boards without protective glasses. The protective glasses should be prepared by the user instead of the transmission equipment supplier.

Maintenance Precautions and Basic Operations OptiX Metro 500 MM

1-2

1. Handling of optical interface of optical interface board and fiber jumper connector

The unused optical interface and unused optical connector should be covered with optical caps. For the optical interface in use, when it is necessary to pull off the fiber jumper from it, please cover the optical interface and the fiber connector with optical caps. In this way, it will Prevent the invisible laser ray from irradiating human eyes. Protect the optical interfaces or fiber jumpers from dust, and so as not to

enhance the loss.

2. Cleaning of the optical interface and fiber connector

The fiber connectors and the optical fiber interfaces must be cleaned with special cleaning tools and materials. These tools and material are available from the manufacturers of optical fiber/optical cables. Always use special cleaning tools and materials to clean the high-power laser interfaces. For low-power laser interfaces, pure anhydrous alcohol can be used if special cleaning tools and materials are not available. Before cleaning the optical interface, please first pull off optical fiber on the board and then pull out the optical interface board. It is recommended that this work should be done or supervised by the engineers of the customer service center of Technical Support Department of Huawei to avoid damage to the optical interface board due to misoperation.

Warning:

It is strictly forbidden to use any cleaning tools and materials that cannot be proved suitable for cleaning the optical fiber connectors and the optical fiber interfaces! Using unqualified tools and materials will damage optical fiber connectors and optical interfaces.

3. Precautions for the loopback of the optical interface

During the hardware loopback test of the optical interface with fiber jumpers, an attenuator must be used to avoid the extra strong receiving optical power from saturating or even damaging the optical receiving module.


1-3

1.1.2 Electrical Safety

1. ESD precautions

Before the maintenance on the equipment, ESD measures must be taken as the stipulations in this section, to avoid damaging the equipment. In the cases of body movements, clothes friction, the friction between the shoes and ground, and plastics held in the hand, human body generates static electromagnetic field and would keep it for a long time. Before touching the equipment, holding boards, PCBs, IC chips and so on, you must wear the ESD wrist strap and ground the other end of the ESD wrist strap properly, lest the static electricity of the human body should damage the static-sensitive components. Refer to Figure 1-1.

Figure 1-1 Wearing an ESD wrist strap

Note: The static electricity produced by the human body can damage the static-sensitive components on the board, such as large scale integrated circuit.


1-4

2. Precautions for board electrical safety

The board should be kept in the ESD bag when it is not used. Wear an ESD wrist and make sure the wrist is well grounded before taking the board.

Moisture-proof treatment of the board

Note: As to the OptiX Metro 500, only SP2D board in extended slot can be plug-in.

Please pay attention to the impact of environmental temperature and humidity on the storage of the backup boards. Desiccant should be placed inside the ESD protection bag to absorb the moisture in the bag and keep the bag dry. When the board encapsulated in the ESD protection bag is taken from a cool, dry place to a hot, humid place, wait for at least 30 minutes before opening it. Otherwise, the moisture will condense on the surface of the board, which may damage the elements.

3. Precautions for power supply maintenance

Never install and remove the equipment power supply with the power on. Never connect or disconnect the equipment power cable with power on. At the moment when the power cable touches the conductor, electric sparks

or arcs will be produced, which can cause fire or injury to the personnel. Before cable is connected, you must make sure whether cable and cable

label are in compliance with the practical installation.

1.1.3 Board Mechanical Safety

Avoid shocks during the transportation of boards, which may result in damage to the boards.

When replacing a board, swap the board with care and strictly follow the instructions.


1-5

1.1.4 Network Management System Maintenance

Do not quit the network management system when its software is working normally. Although quitting the network management system will not interrupt the service on the network, it will disable the NMS to monitor the equipment during the shutdown period and jeopardize the continuity of the equipment monitoring.

Never run any software irrelevant to equipment maintenance on the computer. Never play game on the NMS computer. Never copy file or software which has not been anti-virus scanned to NMS computer. Remove viruses regularly with the latest virus killer software, lest any computer virus infects and damage the NMS.

1.1.5 Modifying Traffic Configuration

Don't use the NMS to groom the service configuration during the traffic peak. Because once there is a fault, there will be great effect. Choose the hour of minimum traffics, such as the nighttime, to perform service grooming.


1-6

1.2 Basic Operations

1.2.1 Swapping Fiber Jumper

The OptiX Metro 500 uses two types of interfaces: SC/PC and FC/PC, as shown in Figure 1-2.

Figure 1-2 SC/PC fiber jumper

Please use special tool (such as fiber extractor) to pull off SC/PC fiber jumper. When inserting the SC/PC fiber jumper, align the connector of the SC/PC fiber jumper with the optical interface on the board, and push it until it clicks into place.

1.2.2 Swapping Board

1. Method of inserting the board

First know each part of the board, as shown in Figure 1-3:

Front panel

Printed Circuit Board

Ejector leverCaptive screw

DB78

Figure 1-3 ach part of the board


1-7

Method of inserting the board is as the following:

(1) Wear an ESD wrist and ensure that the other end of the wrist is well grounded.

(2) To insert the board, first push the board gently along the slide to the bottom of the board position In the event, the board is under floating insertion.

(3) Make sure that the connector of the board aligns with the backplane socket and the guide pin of the backplane aligns with the guide sleeve of the board. Then push the board front panel with proper force until it is basically inserted. If you feel some resistance, please do not insert the board forcedly, instead, you should adjust the board position and then try again.

(4) When the board connector is completely matched with backplane socket (connector and socket can be observed), press the upper and lower ejector levers of the front panels inward till the board is inserted completely, then tighten the captive screws.

Note: 1. Forcibly inserting the board in an improper position will do permanent damage to the equipment. 2. Float inserting the board means that the board is already in the slot but the board connector and motherboard socket are not connected yet; actually, the board is still in not-inserted status. 3. Please remove the fiber (cable) from the front panel of the board before swapping the board. It is forbidden to swap the board with the fiber (cable) on it.

See Figure 1-4.


1-8

SP2D

Figure 1-4 Inserting the board

2. Method of pulling out the board

The operation of pulling out the board is shown in Figure 1-5:

SP2D

Figure 1-5 Pulling out the board


1-9

1.2.3 Resetting SCC Unit

You can reset the SCC Unit through the NMS. In addition, there is a reset button RST on the front panel of the ISU board. You can reset the SCC Unit by pressing the RST button. Neither hard reset nor soft reset of the SCC Unit will affect the service unless. However, when the SCC Unit is in the reset state, the NMS communication will be interrupted temporarily until the SCC unit enters the normal running state again.

Note: The board reset is a dangerous operation, it shall not be done unless in special conditions. If it is really necessary to reset a board, please ask the engineer of Huawei for acknowledgement before you do it.

1.2.4 Testing Trunk Cable with Multimeter

During construction and maintenance, coaxial trunk cable should be tested frequently to judge whether the cable has dry point, open solder point and short circuit, and whether the connection position of trunk cable at the DDF is correct. This is usually mentioned as wire-matching. Operations of the wire-matching are as follow: Short-circuit the signal core and shielding layer at one end of coaxial cable (with a shorting stub or a pair of tweezers), and use a multi-meter to test the resistance between the signal core and shielding layer at the other end. The resistance should be 0. Then break off the short circuit and use the multi-meter to test at the other end. The resistance should be infinite. These two tests show that the tested ends are the two ends of the same cable, and this cable is normal. Otherwise, it shows there is broken point in the cable, there might be dry joint, open solder joint and short circuit at the cable connection point, or these two ends are not the two ends of the same cable.

1.2.5 Loopback Operation

The meanings of inloop/outloop of SDH and PDH interfaces are described in the following:

1. Loop back of SDH interface

(1) Hardware loop back of the SDH interface From the viewpoint of signal flow direction, hardware loop back is generally inloop,


1-10

therefore, we call it as hardware self-loop as well. The hardware loopback of optical interface means to connect the OUT and IN optical ports of optical interface board with a fiber jumper, so as to accomplish signal loopback. There are two hardware self-loop modes: board self-loop and cross self-loop. The board self-loop is defined as connecting the IN to OUT optical ports on the same optical interface board with a fiber jumper. The cross self-loop is defined as connecting the OUT port of west optical interface board to the IN port of east optical interface board, or the OUT port of east optical interface board and the IN port of west optical interface board with a fiber jumper.

Note: An attenuator should be added during hardware self-loop of the optical interface.

(2) Software loopback of SDH interface The software loopback of SDH interface refers to the VC-4 loopback setting in the NMS, which is subdivided into inloop and outloop as well.

(3) Application of VC-4 loopback To locate such faults as service interruption and bit error, the simplest and most effective method is the loopback section-by-section, i.e., locate the fault to a single station or a section of the optical fiber via VC-4 loopback from near to far or from far to near. The sequence of fault location using VC-4 loopback is shown in Figure 1-6:


1-11

Station C

OptiX Metro 500

2Mbit/s port

e

w

e

w

e

STM-1

STM-1

BER tester

1

2

3

4

5

6

Station B

Station A

OptiX Metro 500

OptiX Metro 500

Figure 1-6 Application of VC-4 loopback

Assume Station A is the central office in Figure 1-6, and now the 2Mbit/s service between Stations A and C are interrupted. The steps of locating fault using VC-4 loopback are as follow: (1) First, connect BER tester to the 2Mbit/s port where service is interrupted

and then start to test, as illustrated in Step in Figure 1-6. (2) Find the VC-4 the 2M service is located. Through the NMS, perform inloop

to the VC-4 of the east optical board (e in the diagram) of Station A, as illustrated in Step in Figure 1-6. If the BER tester indicates that the service resumes, it can be judged that there is no fault with Station A. Then go to next step.

(3) Through the NMS, cancel the inloop of the VC-4 of the east optical board of Station A. Then perform outloop to the VC-4 of the west optical board (w in the diagram) of Station B, as illustrated in Step in Figure 1-6. If the BER


1-12

tester indicates that the service is blocked after loopback, it indicates that the fault is basically with the optical fiber between Stations A and B. If the BER tester still indicates that the service is normal, please go to the next step.

(4) Cancel the outloop of the VC-4 of the west optical board of Station B. Then, continue to perform inloop to the VC-4 of the east optical interface board of Station B, as illustrated in Step in Figure 1-6. If the service is blocked after loopback, it indicates the fault is with Station B. If the service is still normal after loopback, please go to the next step.

(5) Cancel the inloop of the VC4 of the east optical board at Station B, perform outloop to the VC4 of the west optical board of Station C, as illustrated in Step in Figure 1-6. If the service is blocked after loopback, it shows that the fault is with the fiber between Stations B and C. If the service is normal, the fault is with Station C.

(6) Cancel the outloop of the VC4 of the west optical board of Station C. Next, perform inloop to the corresponding 2Mbit/s TU interface of Station C instead of VC-4 loopback. Then, the fault can be judged either at Station C or at the trunk cable or at the exchange. The inloop of TU interface is illustrated in Step in Figure 1-6.

Review the steps of , , , , , and , the loopback idea from near end to far end is very clear.

Note: 1) Since the VC-4 loopback is aimed at the whole VC-4, all services in the VC-4 will be affected. 2) No matter whether the bit rate on the optical path is STM-1 or STM-4, if VC-4 loopback is performed on the first VC4 of the optical path, ECC communication may be affected and then the downstream NEs cannot be logged on. Use the function with care! 3) The VC-4 loopback must be cancelled after test! (Set to No loopback)

2. Loopback of PDH interface

(1) Hardware loopback of PDH interface Hardware loopback of PDH interface is to connect the receive ports with the transmitter ports by cables.


1-13

(2) Software loopback of PDH interface The software loopback of PDH interface is to set inloop or outloop for PDH interface via the NMS. Whether a certain 2Mbit/s path in its entirety is normal can be tested through loopback of PDH interfaces and outloop test in combination with BER tester. For specific operation, please refer to the Operation Manual of the corresponding NMS. (3) Application of outloop and inloop If any alarm occurs in some 2Mbit/s paths, or traffics of the switching system are interrupted, the general troubleshooting methods are to perform outloop and inloop on both ports of corresponding 2Mbit/s path. At the same time we should perform loopback at the DDF to locate the fault, as illustrated in Figure 1-7.

OptiX Metro 500 OptiX Metro 500

A Office B Office

RX

RXTX

TX

Swithing

DDF

swithing

DDF

RX TX

RXTX

RX TX

RX TX

RXTX

RX TX

1

2

4

3outloop inloop

Figure 1-7 Outloop and inloop application of the PDH interface

In Figure 1-7, suppose that Office A is the central office and the exchange room reports that there is a 2Mbit/s service interruption between Office A and Office B. Then, the sequence of the PDH tributary interface loopback is as follows: (1) First, at the DDF of Office A, perform loopback to the exchange side with a

self-loop cable and observe the trunk status of the exchange, as shown in Step in Figure 1-7. If the trunk status of the exchange is abnormal, it indicates the problem is between the exchange and the DDF. If the trunk status of the exchange is normal, go to the next step.

(2) Cancel the self-loop cable from the DDF to the exchange. Then, through the NMS, perform outloop to the corresponding 2Mbit/s interface of the OptiX Metro 500 at Office A, and observe the trunk status of the exchange at Office A or connect a BER tester to the DDF for test, as shown in Step in Figure 1-7. If the trunk status of the exchange is abnormal, it indicates the


1-14

problem is with the tributary board of the OptiX Metro 500 at Office A or the cable between the OptiX equipment and the DDF. If the trunk state is normal, please go to the next step.

(3) Through the NMS, cancel the outloop to the corresponding 2Mbit/s interface of the OptiX Metro 500 at Office A. Perform inloop on the corresponding 2Mbit/s path port of the OptiX Metro 500 at Office B. And observe the trunk status of the exchange at Office A or the status of BER tester, as illustrated in Step in Figure 1-7. If the trunk status of the exchange is still abnormal, all of the tributary board, cross-connect board, line board in OptiX equipments both at Office A and Office B may be faulty, as well as optical fibers, because service passes through all these sections. If the trunk status of the exchange is normal, please go to the next step.

(4) Cancel the inloop to the corresponding 2Mbit/s interface of the OptiX Metro 500 at Office B. Then, at the DDF of Office B, use a self-loop cable to perform loopback towards Office A and observe the trunk status of the exchange at Office A or the status of the BER tester. If the trunk status of the exchange is still abnormal, it can be affirmed that the problem may exist on the cable between OptiX equipment and the DDF or on the tributary unit of OptiX equipment at Office B. If the trunk status of the exchange is normal, the problem exists between the exchange and the DDF at Office B.

1.2.6 Bit Error Test

When performing bit error test with the BER tester, the service access point, such as E1 and STM-1 interface, is generally taken as the test point. There are two test modes available: on-line test or off-line test.

1. On-line test method

First, select a service channel in use (E1 or STM-1) and find the port on the DDF corresponding to this channel. Then, connect one end of the test cable with the on-line test connector of the port on the DDF and the other end with the on-line test interface of the BER tester. In normal cases, there should be no bit error in 24 hours. For the setting of the BER tester, please refer to its usage instructions. Note that the meter is set to on-line test at the event.

2. Off-line test method

This is a commonly used bit error test method. First select a service channel (E1 or STM-1), connect the TX and RX ports of BER tester with the RX and RTX PDH/SDH interfaces of this service channel in this station respectively, then perform inloop to


1-15

the PDH/SDH interface of the opposite station (e.g., perform hardware self-loop at the DDF), and test the bit error. For the BER tester usage, please refer to its usage instructions. Under normal conditions there should be no bit error. The block diagram of bit error test connection is shown in Figure 1-8:

OptiX Metro 500

OptiX Metro 500

BER tester Tributary inloop

Figure 1-8 Bit error test

Note: The test meter should be grounded properly. It is suggested that other electric appliances not be switched on/off in the test course.

1.2.7 Cable Tag Description

To ensure correct optical fiber connection and facilitate future maintenance, both ends of the fiber jumper should be marked with tags. Depending on the connectivity of the transmission equipment, the tags of fiber jumpers can be prepared in two different ways. One kind of tags is used for inter-station connection of the transmission equipment, where tags are pasted on fiber jumpers at the transmission equipment side. The other kind of tags is used for intra-station connection of the transmission equipment, where tags are pasted on both ends of fiber jumpers. It should be noted that the tag content on both ends of the same fiber should be the same. In case of the inter-station connection of transmission equipment, the tags bear the contents as shown in Table 1-1.


1-16

Table 1-1 Content of tag on inter-station fiber Tag content Meaning Remarks

I: receive optical interface of local station; O: transmit optical interface of local station

A: opposite station name B: slot number of opposite station Physical slot number of

opposite station. I/O--A--B--C

C: optical interface number of opposite station

For a multiple- optical-interface board, the optical interfaces are numbered 1~8 top to bottom and left to right.

Figure 1-9 shows a typical fiber jumper tag in the inter-station connection.

Optical fiber

35.3mm

36.1mmOptical fiber

Figure 1-9 Tag on fiber jumper transferred via the ODF

The content of the tag on the intra-station fiber jumper is shown in Table 1-2:


1-17

Table 1-2 Content of tag on intra-station fiber Tag content Meaning Remarks

O: optical TX interface; I: optical RX interface.

MN-O: rack number; B: NE position

O/I-MN-O-B-C-D

C: board position number; D: optical interface number.

For a multiple- optical-interface board, the optical interfaces are numbered 1~8 top to bottom and left to right.

O: optical TX interface; I: optical RX interface.

MN-O: rack number; B: NE position.

TO: OUT/IN-MN-O-B-C-D

C: board position number; D: optical interface number.

For a multiple- optical-interface board, the optical interfaces are numbered 1~8, top to bottom and left to right.

Figure 1-10 shows a typical tag of fiber jumper when the transmission equipment is connected directly with fiber jumper.

Optical fiber

Optical fiber

35.3mm

36.1mm

TO :

Figure 1-10 Preparation of fiber jumper tag with transmission equipment connected directly with fiber jumper


1-18

1.2.8 Receiving/transmitting Optical Power Test

1. Transmitting optical power test

As shown in Figure 1-11, the transmitting optical power is measured in the following steps: (1) Set the receiving optical wavelength of optical power meter to be the same

as the tested optical wavelength. (2) Connect the testing fiber jumper to the OUT interface of the tested optical

interface board. (3) Connect the other end of this fiber jumper to the test input interface of the

optical power meter, wait till the receiving optical power is stable, read the optical power value, i.e., the transmitting optical power of this optical interface board.

Note: (1) To do this test, you have to keep the fiber connector clean and well connected, and also keep the ring flange of the board front panel well connected and clean. (2) Test the attenuation of fiber jumper in advance; (3) Different fiber jumpers should be used for single-mode and multi-mode optical interfaces. (4) To test fiber jumper, the fiber jumper with FC/PC (round) or SC/PC (square) connector should be selected according to the interface type. (5) Optical power meter should work under the mode of Root Mean Square.

OUT

Optical power meter

Display

Control panel

Optical interface board

Test port

Fiber jumper

Power supply

Figure 1-11 Diagram of transmitting optical power test


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2. Receiving optical power test

The receiving optical power test is shown in Figure 1-12. The test operations are as follows: (1) Set the receiving optical wavelength of optical power meter to be the same

as the tested optical wavelength. (2) In this station, select the fiber jumper connected to the transmit optical

interface (OUT) of the adjacent station. (Under normal conditions, this fiber jumper is connected to the receive optical interface of the optical interface board in this station).

Connect this fiber jumper to the input interface of the optical power meter, wait till the receiving optical power is stable, read the optical power value, i.e., the actual receiving optical power of this optical interface board.

OUT

Optical power meter

Display

Control panel Test port

Fiber jumper

ODFOptical cable

ODF Fiber jumper

Power supply

Local station Abjacent station Figure 1-12 Diagram of receiving optical power test

The precautions are the same as those of transmitting optical power test.

1.2.9 Preparation of the Ethernet Cable of NMS Computer

To connect NMS computer with gateway NE via Ethernet cable, you can use cross-connection cable and straight-through cable. The cross-connection cable is used for direct connection between the NMS computer and the gateway NE while straight-through cable is used for connection between the NMS computer and the gateway NE through a hub. The two differ from each other in the connectivity of the cores of the cable. Both these network cables use the RJ-45 connector, as shown in Figure 1-13:


1-20

PIN #1PIN #8

Figure 1-13 RJ-45 connector

The correspondence between core colors of both ends of the straight-through cable is as follows; Table 1-3 Connection of the straight-through cable

Connector at the head 8-core, category 5 twisted pair Connector at the end

Pin 1 White (orange) Pin 1

Pin 2 Orange Pin 2

Pin 3 White (green) Pin 3

Pin 4 Blue Pin 4

Pin 5 White (blue) Pin 5

Pin 6 Green Pin 6

Pin 7 White (brown) Pin 7

Pin 8 Brown Pin 8

The connection of the cross-connection cable is shown in Table 1-4.


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Table 1-4 Connection of the cross-connection cable

Connector at the head 8-core, category 5 twisted pair Connector at the end

Pin 1 White (orange) Pin 3

Pin 2 Orange Pin 6

Pin 3 White (green) Pin 1

Pin 4 Blue Pin 4

Pin 5 White (blue) Pin 5

Pin 6 Green Pin 2

Pin 7 White (brown) Pin 7

Pin 8 Brown Pin 8

OptiX Metro 500 MM

2-1

2 Routine Maintenance

2.1 Maintenance Overview

2.1.1 Maintenance Objective

The reliable operation of the system in different running environments largely depends on efficient daily maintenance. To timely find out and solve the problem is the objective of routine maintenance. This chapter describes the content of routine maintenance of the OptiX Metro 500 equipment and the operation procedures. It provides the user with basic methods and reference in determining the local office maintenance plan.

2.1.2 Classification of Maintenance

According to the maintenance cycle the maintenance is classified into the following types:

1. Emergency maintenance

Emergency maintenance refers to the maintenance executed due to transmission equipment fault and network adjustment, such as the maintenance conducted in case of subscriber complaint for faults, equipment damage, or line faults. Furthermore, the problems detected and recorded in daily routine maintenance are also sources of the emergency maintenance.

Routine Maintenance OptiX Metro 500 MM

2-2

2. Daily routine maintenance

Daily routine maintenance refers to those maintenance items you should perform everyday. It can help maintenance personnel learn the equipment operation condition at any time so as to find and solve the problems in time. If a fault is detected in daily maintenance, please record its specific physical location, phenomena and process for timely fault removal.

3. Periodical routine maintenance

Periodical routine maintenance refers to the maintenance performed periodically. Through it, maintenance personnel can get the long-term running status of the equipment The periodical routine maintenance falls into quarterly maintenance and yearly maintenance.

2.1.3 Basic Principles for Routine Maintenance

The basic principle of routine maintenance is to find and solve problems in time. Qualified maintenance personnel should be able to locate and eliminate equipment failure quickly in case any problem occurs. What is more important, he should be able to find and clear hidden troubles in time through routine maintenance, so as to enable equipment to run stably for a long period of time. Excellent and effective maintenance of the equipment would reduce the fault rate and increase the service life of equipment. If the maintenance personnel can detect any fault presymptom in time during routine maintenance before the fault occurs and nip it in the bud, the troubleshooting mess and economic losses caused by service interruption can be avoided. Moreover, the damage to the equipment caused by the fault degradation can be prevented, the maintenance costs can saved, the board replacement rate can reduced and the life span of the equipment can be prolonged. All these requires the maintenance personnel have not only profound knowledge and rich experience, but also sharp eyes to look into details.

2.1.4 Maintenance Capability of OptiX Metro 500 Equipment

The OptiX Metro 500 equipment is designed to take into account the users requirements for maintenance with respect to both hardware and software. The OptiX Metro 500 equipment can provide powerful maintenance capability, which includes the following:

1. In daily maintenance

(1) Dynamically monitoring the operation conditions and Qos of the equipment


2-3

in the network through the NM system. (2) Assisting the maintenance personnel in monitoring the equipment operation

through the equipment indicator. 2. In troubleshooting

(1) Providing automatic service protection in case of abnormal service interruption.

(2) Dynamically monitoring the fault of the equipment as a whole through the NM system.

(3) Providing a variety of loopback testing functions.


2-4

2.2 Routine Maintenance Items of

Equipment

Table 2-1 lists the routine maintenance items, which are applicable to the maintenance personnel for all equipment facilities. Table 2-1 Routine maintenance items and maintenance cycle of the OptiX transmission equipment

Maintenance test item Maintenance Type Cycle Check the equipment temperature Equipment maintenance Daily

Log in NMS as a lower-level user NMS maintenance Daily

Check the NE and board state NMS maintenance Daily

Check alarm NMS maintenance Daily

Monitor performance event NMS maintenance Daily

Check protection switching NMS Maintenance Daily

Query log record NMS Maintenance Daily

Check ECC route NMS maintenance Daily

Check equipment environmental variables NMS maintenance Daily

Check NE time NMS Maintenance Daily

Query board configuration NMS Maintenance Daily

Check the fan periodically Equipment maintenance 2 weeks

Check service -- bit error test Equipment maintenance 1 month

Check the start and shutdown of NMS NMS maintenance 1 month

Modify login password of NMS user periodically NMS maintenance 1 month

Backup and dump NMS database NMS maintenance 1 month

Maintain NMS computer NMS maintenance 1 month

Test remote maintenance function NMS maintenance 1 month


2-5

2.2.1 Observing Indicators

There are four indicators on the front panel of the OptiX Metro 500,as showed in Table 2-2.

Table 2-2 indicators silkscreen Description remarks RUN Running indicator Off : OptiX Metro 500 is not powered

Flash per 0.5 second : waiting for loading software

Quick Flash : loading software

Slow flash : running normally

CRT critical alarm indicator

Off :no critical alarm

On :critical alarm

MAJ Major alarm indicator

Off : no major alarm

On : major alarm

los Optical interface indicator

2.2.2 Checking Equipment Temperature

The operating temperature requirements for the equipment are shown in Table 2-3: Table 2-3 Temperature requirements for the equipment

Operational Condition Temperature (C) long-term operating conditions 0C~45C

Safe working condition -5C~50C

Safe operating condition means that the successive operating time does not exceed 72 hours and the accumulated time every year does not exceed 15 days.

Touch the board front panel with your hand to detect the board temperature. Equipment temperature should be checked once a day.


2-6

2.2.3 Service Check -- Bit Error Test

This is one of tests on the long-term stabile operation and working performance of the transmission system. In routine maintenance, periodical spot test should be performed to the service channel on condition that the currently running services are not interrupted, so as to judge whether the performance of all the service channels is normal. Approach 1: if there exist configured but not used service channels between two stations, we can test the unused service channels to check the quality of the service channels between the two stations; Approach 2: if the configured service channels are all used between two stations, we can temporarily disconnect the service channel used for protection to make bit error test when the service is comparatively light, and judge the quality of the service channel between two stations based on this test. Approach 3: if the above two approaches are not available, we can monitor the quality of the service channel through the performance and alarms reported by the NMS. Generally, for the selected service channel, bit error test is carried out by means of setting inloop on the 155Mbit/s electrical interface board at the remote station, and testing bit error with a meter in this station. The test period is 24 hours, the test result should be zero. Please note that the bit error detector should be in good grounding during the test. To avoid interference, make every effort not to turn on/off other electric appliances during the test. Bit error test should be performed once a month. After the test is completed, the inloop setting of the electrical interface board must be canceled.

Note: The test meter should be grounded properly. It is suggested that other electric appliances not be switched on/off in the test course. During the test process, when performing loopback to the service channel of the electrical interface board, first consider to perform hardware loopback to the external DDF of the equipment. If the test result is abnormal (such as a great amount of bit errors), perform loopback in the wiring area of the subrack instead. If the fault remains after the hardware loopback, perform board software loopback to the service channel of the electrical interface board. Note that after the test is completed, be sue to cancel the loopback setting of the electrical interface board.


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2.3 Routine Maintenance Items of

NMS

The OptiX iManager NMS is an important tool used in equipment routine maintenance. To ensure safe and reliable operation of the equipment, maintenance personnel in the NMS station should check the equipment via the NMS daily. For detailed NMS operations, please refer to OptiX iManager T2000 Integration Network Management System for Transmission Network (Sub-Network Level) Operation Manual.

Prompt: OptiX iManager T2000 is a network management system for transmission equipment NE, and it is oriented to management at the sub-network level. Its operating platform is Windows 2000 or Unix.

OptiX Metro 500 MM

3-1

3 Principle for Generation of

Alarm and Performance Event

This chapter covers principle for the generation of alarm and performance event of SDH service and its application in troubleshooting.

3.1 Overview of SDH Alarm and

Performance Event

There are abundant overhead bytes in SDH frame structure, including regenerator section overhead, multiplex section overhead, and path overhead. These overhead bytes carry alarm and performance event information, thus enabling SDH system a strong ability of on-line alarm and error monitoring. An understanding of the generation and monitoring modes of the alarm information allows you to locate the failure rapidly. The SDH alarm signal flow is shown in Figure 3-1.

Principle for Generation of Alarm and Performance Event OptiX Metro 500 MM

3-2

T1512780-93/d02

SPI RST (Note 1) MST MSA HPOM HUG HPC HPT HPA LPOM LUG LPC LPT LPA

PhysicalSection

RegeneratorSection Multiplex Section Higher Order Path Lower Order Path

UnusedLPC output/LP-UNEQ

LOFRS-BIP

Error (B1)Regeneratedsignal

passed through

HP-UNEQHP-TIM

HP-SLMHP-BIP Error (B3)

HP-FEBEHP-FERFHP-FERFHP-FEBE

LOS

MS-AISMS-Exc. Error (B2)MS-BIP Error (B2)

MS-FERFMS-FERF

AU-AISAU-LOP

HP-LOM/TU-LOP

LP-UNEQLP-TIM

LP-SLMLP-BIP Error (B3/V5)

LP-FEBELP-FERFLP-FERFLP-FEBE

AU-AIS

TU-AIS

TU-AIS

HO Path signal passed throughHOVC with POH and unspecified payloadHO unequipped signal

LO Path signal passed throughLOVC with POH and unspecified payloadLO unequipped signal

UnusedHPC output/HQ-UNEQ

1

1

1

1

1

1

1

1

1

DetectionGenerationInsertion of all-ones (AIS) signalAlarm Indication SignalFar End Block ErrorFar End Receive FailureLoss Of FrameLoss Of MultiframeLoss Of PointerLoss Of SignalSignal Label MismatchTrace Identifier MismatchUnequipped signal per Recommendation G.709

1AISFEBEFERFLOFLOMLOPLOSSLMTIMUNEQ

1.This column represents the degenerateconnection function present in aregenerator.NOTES

2.The insertion of all-ones(AIS) and FERFon certain defects may be optional.This figureshowstheseoptionsasdashed lines. SeeRecommendation G.783.

FIGURE 2-2/G.782SDHmaintenancesignal interaction

Figure 3-1 SDH alarm signal flow


3-3

3.1.1 Terminology Agreement

In order to describe the positions where common alarms and performance events are generated and the generation modes, it is better to describe these common alarms and performance events in detail along the signal flow. Signal flow, here, will be classified into downlink and uplink signal flows according to the signal flow directions. The so-called downlink signal flow refers to the signal direction from the SDH interface, to the cross-connect unit, and then to the PDH interface. On the contrary, the uplink signal flow refers to the signal direction from the PDH interface, to cross-connect unit, and then to the SDH interface.

3.1.2 Two Common Alarms

AIS alarm (i.e. all "1"s alarm) inserts the all "1"s signal to the lower level circuits, indicating that the signal is unavailable. Common AIS signals include MS-AIS, AU-AIS, TU-AIS. RDI (remote receive defect indication) alarm: is the alarm transferred back to the home station from the opposite station after the opposite station has tested alarms of LOS (loss of signal), AIS and TIM (trace identifier mismatch). Common RDI alarms include MS-RDI, HP-RDI and LP-RDI.

Note: The alarm detected may be caused by the opposite station or due to other causes. For example, R-LOS alarm is caused by broken fiber, and HP-LOM (higher order path loss of multiframe) alarm at the home station is caused by the failed cross-connect unit at the opposite station.


3-4

3.2 Generation and Detection of

Alarm and Performance Event in

Signal Flow of Higher Order Part

The fault locating principle is "line first, then tributary; high level first, then low level". Since the alarm and performance data generated in the higher order part will cause the report of the lower order alarm and performance events. We shall first focus on the alarm, performance information generated between the SDH interface and the cross-connect unit during maintenance. The signal flow chart of this route is illustrated in Figure 3-2.

"1" LOSSTM-1 optical interface

B1BI Err.

K2

AIS

MS-AIS

k2MS-RDI

B2

M1

Frame synchronizer and RS overhead processor

MS overhead processor

C2

AU-AISAU-LOP

J1HP-UNEQHP-TIM

B3B3 Err.

G1G1

HP-REI

HP-RDI

MS-REI

H4C2

HP-LOM

HP-SLM

B2-Err.

Downlink signal flow

Pointer processor and HP overhead processor

AIS

A1, A2LOF

Signal transfer point Alarm termination point(Report to SCC unit)(Insert down all "1"s signal)

H1,H2H1,H2

"1"

"1"

Alarm report or return

(RST) (MST) (MSA, HPT)

Cross-connect unit

Figure 3-2 Flowchart of alarm signals generated between the SDH interface and the cross-connect unit

Note: According to the processing positions of various overhead bytes in the STM-1 frame structure, we divide the overhead bytes into four modules: regenerator section overhead, multiplex section overhead, and higher order path overhead and the pointer. If the first two modules have problems, generally all the higher order paths will be affected, while the problem occurs in the overhead bytes of the last module will only affect a certain higher order paths. Therefore, we can usually deduce the influencing factor of the problem, and how to select the paths during the test.


3-5

We'll describe the signal flow and processing of each overhead byte module by module in the following.

3.2.1 Downlink Signal Flow

1. Frame synchronizer and regenerator section overhead processor

Regenerator section overheads that will be mainly processed in this section are: framing byte (A1, A2), regenerator section trace byte (J0), error checking byte (B1). The alarm signal flow is as follows: (1) When the STM-1 optical signal from the optical line enters the optical

receiving module, first, it is recovered into electrical signal after optical/electrical conversion (O/E conversion) and then sent into frame synchronizer and scrambler for processing. In this process, the O/E module monitors this signal. If it is found that there is no light in the input signal, optical power excessively low or high and code type of the input signal mismatch, R-LOS (loss of signal) alarm will be reported.

Prompt: No light usually occurs in the case that the fiber is broken, the optical transmitting module at the opposite station fails or the optical receiving module at the home station fails. The cause of excessively low optical power may be too much fiber attenuation or poor contact of the optical joint, etc. Over high optical power refers to the received optical power overload. If this happens, check whether the optical attenuator is damaged, or the transmission distance of the optical board is suitable, etc. The code type mismatch usually occurs when the signal rate between upstream station and downstream station is inconsistent, or failed STG unit at upstream station will cause data transmission disorder, etc. At this moment it is necessary to check whether the optical board at upstream station is matched or the STG unit and cross-connect unit are in normal operation, etc. R-LOS alarm has no relation with overhead bytes, and it is only related to the quality of input signal.

After R-LOS alarm occurs, only when optical receiving module at the home station has continuously tested two correct patterns of code type, and meanwhile it has not tested any new R-LOS alarm, can SDH equipment quit from R-LOS status and enter normal status. In case R-LOS alarm occurs, the system will insert all "1"s signal to the lower level circuits. (2) After frame synchronizer has received STM-1 signal sent from the


3-6

optical/electrical conversion module, it captures A1, A2 framing bytes in the signal. Meanwhile it extracts line reference synchronous timing source from the signal and sends it to the STG unit for clock locking.

Normally, the A1 value is F6H, and the A2 value is 28H. If incorrect A1 and A2 values are detected in five successive frames, R-OOF (out of frame) alarm will be reported. If R-OOF alarm lasts for more than 3 ms, it will report loss of frame alarm R-LOF and insert all "1"s signal. In case of R-LOF alarm, if the frame alignment state lasts for more than 1 ms, that means the equipment has resumed to normal. J0 byte is used to confirm that both ends of the regenerator section are in continuous connecting state. It requires that J0 bytes at receive end and transmit end be fully matched. If they are not matched, the equipment will report J0-MM trace identifier mismatch alarm. Scrambler is mainly engaged in unscrambling the bytes in the STM-1 signals except for the A1, A2 and J0 bytes. (3) The regenerator section overhead processor extracts and processes other

regenerator section overhead bytes in the STM-1 signal. Among all the bytes, B1 byte is of utmost importance.

If the B1 byte recovered from STM-1 signal is not in compliance with BIP-8 computing result of the preceding STM-1 frame, it will report B1 error. If the number of B1 bit errors exceeds the threshold 10-3, the B1-OVER alarm will be reported. When ten serious errored seconds (SES, i.e. the errored blocks reach to 30% in one second) in regenerator section appear consecutively, it is considered that RSUATEVENT (regenerator section unavailable time event) occurs. At the same time, in this section these bytes, such as F1, D1~D3 and E1, which have nothing to do with alarm will be sent to the SCC unit and OHP unit.

2. Multiplex section overhead processor

Multiplex overhead bytes that are related to alarm and performance and will be processed in this part include: automatic protection switching channels (K1, K2), BIP-24 (B2), multiplex section remote error indication (M1). The signal flow is as follows: (1) Multiplex section overhead processor extracts multiplex section overhead

bytes in STM-1 signal for processing and completes SF and SD detection. It sends D4~D12, S1 and E2 to the SCC unit and overhead unit, meanwhile realizes the shared multiplex section protection (MSP) function by the cooperation of the SCC unit, cross-connect unit and K1, K2 bytes.

If the b6-b8 of K2 byte is detected as 111, the MS-AIS alarm will be reported and all 1s signal will be inserted.If the b6-b8 of K2 byte is detected as 110, the MS-RDI alarm will be reported. (2) If the B2 byte recovered from the STM-1 signal is not consistent with the


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computing result of BIP-24 in the lastly received STM-1 frame (All bits expect for the regenerator section overhead), then the processor reports the B2 bit error.

Whether to report MS-REI is determined by M1 bytes. MS-REI transfers the number of error interleaved block detected by B2 byte. If B2 bit error exceeds the threshold 10-6, B2-SD alarm will be generated. If the B2 bit error exceeds the threshold 10-3, B2-OVER alarm will be reported. In multiplex section protection mode, the B2-SD and B2-OVER alarms will give rise to the multiplex section protection switching. When B2 byte detects SES consecutively for 10 seconds (errored block reaches 30% in one second), it is considered as an MSUATEVENT (multiplex section unavailable time event).

3. Pointer processor and higher order path overhead processor.

This part processes higher order pointer justification and higher order path overhead. Bytes related to pointer justification are H1, H2 and H3, and those related to alarm and error are path trace byte (J1), signal label byte (C2), path BIP-8 (B3), path status byte (G1), position indicator byte (H4). Their alarm flows are as follows: (1) The pointer processor interprets and justifies the pointer on the basis of H1,

H2 bytes of each AU-4, completes frequency and phase calibration and tolerates phase jitter and wander in the network. At the same time, it locates each VC-4 and sends it to corresponding higher order path overhead processor. If H1 and H2 bytes of AU pointer are detected to be all "1"s, AU-AIS (administrative unit-alarm indication signal) alarm will be reported and all "1"s signal will be inserted. If the indicator values of H1 and H2 are illegal (not in the normal range of 0~782) and receives illegal pointers consecutively in eight frames, then it will report AU-LOP (administrative unit-loss of pointer) alarm and insert all "1"s signal.

In case AU pointer positive justification occurs, the number of the PJCHIGH of the MSA increases by 1. In case AU pointer negative justification occurs, the number of the PJCLOW of MSA increases by 1. (2) Higher order path overhead processor processes higher order path

overhead (HPOH) bytes received in N VC-4s. The processing mode for each byte is as follows.

If J1 byte value detected is not the same as the preset, HP-TIM alarm will be reported and all "1"s signal will be inserted. If C2 byte is detected as 00, Higher Order Path- Unequipped (HP-UNEQ) alarm will be reported and all "1"s signal will be inserted. When C2 byte detected is different


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from the preset, Higher Order path - Signal Label Mismatch (HP-SLM ) alarm will be reported and all "1"s signal will be inserted. If B3 byte recovered from HPOH is not in compliance with BIP-8 computing result of VC-4 signal of the preceding frame, B3 bit error will be reported. In OptiX STM-1 (N


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H4 byte will not be processed in the uplink direction. (3) Pointer processor generates N AU-4 pointers, adapts VC-4 into AU-4,

among which AU-4 pointer is represented by H1 and H2 bytes, then N AU-4s are multiplexed into STM-1 signal by multiplexing processor and sent to multiplex section overhead processor.

2. Multiplex section overhead processor

Multiplex section overhead processor sets MSOH bytes (including K1, K2, D4-D12, S1, M1, E2 and B2) for the received STM-1 signal. If R-LOS, R-LOF or MS-AIS alarms are detected in the downlink signal flow, the b6-b8 of K2 byte will be set to 110 and MS-RDI will be returned to the remote. If B2 bit errors are tested in the downlink signal flow, MS-REI alarm will be returned to the remote via the M1 byte..

3. Frame synchronizer and regenerator section overhead processor

(1) Regenerator section overhead processor sets overhead bytes in regenerator section (including A1, A2, J0, E1, F1, D1-D3 and B1), and send a complete STM-1 electrical signal to frame synchronizer and scrambler.

(2) Frame synchronizer and scrambler scrambles STM-1 electrical signals (except for A1, A2, J0), then STM-1 electrical signal is converted into STM-1 optical signal by the E/O module and sent out of the optical interface.


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3.3 Generation of Alarm and

Performance in Signal Flow of

Lower Order Part

The following will describe the processing of the signal flow between PDH interface and the cross-connect unit, and the generation of alarms by taking 2Mbit/s service as an example. The alarm signal flow is as shown in Figure 3-3.

HPA , LPT

Signal flow

Signal transfer point Alarm termination point

(Report to the SCC unit)(Insert down all "1"s signal)

V5V5 LP-UNEQ

J2

V1, V2

V1, V2

H4

LP-TIM

TU-LOP

TU-AIS

HP-LOM

LP-RDIV5

BIP-2

LP-REI

T-ALOS

All "1''s

LPA PPI

V5

V5

LP-TFIFO

LP-RFIFO

Alarm report or return

E1-AIS

E1-AIS

E1 interface

LP-SLM

Cross-connect board

All "1''s

Figure 3-3 Flow chart of the generation of alarm signals between the 2M PDH interface and the cross-connect unit

In view of different characteristics of processing the overhead bytes in each part, the lower order part is divided into several functional modules in the above diagram. They are higher order path adapter (HPA), lower order path terminal (LPT), lower order path adapter (LPA) and asynchronous physical interface in sequence. In the following, we will take these functional modules as index to introduce alarm signal flow.


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3.3.1 Downlink Signal Flow

1. Higher order path adaptation (HPA) and lower order path terminal (LPT)

This part is the core of lower order part, because most of the lower order overhead bytes are processed here, including lower order path pointer indicator bytes (V1, V2, V3), V5 byte, and path trace byte (J2). (1) VC-4 signal from the cross-connect unit is sent to HPA. (2) HPA demaps the VC-4 into VC-12. Pointers of all VC-12s are decoded, so

as to provide, between the VC-4 and the VC-12, the frame offset information in byte.

When node clock at TU-12 assembler is different from local reference clock, this process needs continuous pointer justification. Positive TU pointer justification (LPPPJE) and negative TU pointer justification (LPNPJE) will be tested in downlink signal flow. The TU pointer justification count threshold-crossing (The threshold is adjustable) is expressed in a group of alarms HPADCROSSTR. HPADCROSSTR includes HPADPJCHIGHCX15 (TU pointer positive justification count threshold-crossing for 15 minutes), HPADPJCHIGHCX24 (TU pointer positive justification count threshold-crossing for 24 hours), HPADPJCLOWCX15 (TU pointer negative justification count threshold-crossing for 15 minutes) and HPADPJCLOWCX24 (TU pointer negative justification count threshold-crossing for 24 hours). If incorrect H4 multiframe byte sequence is detected in the downlink, then the HP-LOM alarm is reported. If V1 and V2 are detected to be all 1s, TU-AIS alarm will be reported. If the values of V1 and V2 are tested illegal, TU-LOP alarm will be reported. If either of these two alarms occur, all "1"s signal will be inserted down to the next function block. In addition, if TU-AIS alarm is received, AIS signal will be inserted in the downward data, and LP-RDI will be returned. To return LP-RDI is to set the b8 of V5 byte to "1". (3) The VC-12 signal flow is sent to the LPT unit for the V5 byte processing. Composition of timeslot structure of V5 byte is as shown in Figure 3-4.

b1 b2 b3 b4 b5 b6 b7 b8

BIP-2 error check

V5 byte

Inconsistent:LPBBE 1:LP-REI UnusedSignal label

000:LP-UNEQ 1:LP-RDI Figure 3-4 The structure of V5 byte

Detect the b5-b7 of V5 byte in the downlink signal flow, and report them as signal labels. If they are 000, it means that lower order paths are not equipped (LP-UNEQ),


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and insert AIS signal into the lower level circuit. If signal labels mismatch, LP-SLM will be reported and AIS signal will be inserted to the lower level circuit. Path RDI information in the b8 of V5 byte will be terminated, and REI will be reported. Detect error monitoring bits of the b1 and b2 of V5 byte and calculate BIP-2 for VC-12. BIP-2 value calculated for the current frame will be compared with the b1 and b2 of V5 byte recovered from the next frame. LPBBE will be reported if they are inconsistent. Meanwhile the b3 of V5 byte is recovered, and if it is "1", it means that the remote has BIP-2 bit error and will report it as LPFEBBE. The b4 of V5 byte is not used. When BIP-2 finds ten consecutive SESs (errored block reaches 30% in one second) appears continuously during the test, it is considered as an LVCUATEVENT (lower order virtual container unavailable time event). (4) At the same time, the lower order path trace identifier J2

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