trouble shooting fault analysis

7/30/2019 Trouble Shooting Fault Analysis

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OptiX BWS 1600G

System Troubleshooting


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Objectives

Upon completion of this coures,you will be able to:

Compare the different use of Common Methods ofFault Locating.

Illustrate Regular Operation for Troubleshooting.Describe the Basic Thoughts and Methods of FaultLocating.

Know the Fault Handling Flow.

Analyze and Eliminate the common faults.Improve the ability of eliminating faults through

case analysis


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References

Optix BWS 1600G Maintenance

Manual(Troubleshooting)

Optix Metro6100 Maintenance

Manual(Troubleshooting)

Optix Metro 6040 User Manual


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Contents

Chapter 1 Operations for troubleshooting

Chapter 2 Basic Thoughts and Methods of

Fault Locatiting

Chapter 3 Fault Handling Flow

Chapter 4 Fault classification and location


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Review Point

Left is defined as

west and right aseast in a chain

network.

The ring network takes

counter-clockwise

direction as the primary

ring direction.

WEST EAST

EAST WEST

WEST

WEST EAST

EAST

EAST

WEST


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Key Operation

Software Loopback (Use-T2000)

Cross Loopback (Trans & Receive)

Hardware Loopback (Use Physical Fiber)

Reset Board

Clean Optical Interface

Optical Power Test Replacement of Board


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Software Loopback: Outloop

* Loop a received signal directly backto its

corresponding output port(WDM orclient

side).

* It can be used to test the fiber line

andconnectors.

Outloop OTU

OUT Outloop

Client side WDM side

Client side WDM side


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Software Loopback: Inloop

OUT inloop

Inloop OTU

WDM side

WDM side

Client side

Client side

Inloop at client side of OTU

Inloop at WDM side of OTU


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Cross Loopback

Note: LWM and LWX boards support cross loopback.Client side OTU WDM side

A 2 c

1 2

1

B D

Optical

Receiving

module

Optical

Receivingmodule

Optical

Transmitting

module

Optical

Transmitting

module

Broadcast receiving signal at client sideTo optical transmitting modules at both

Client side and WDM side

Broadcast receiving at WDM side to optical

Transmitting modules at both WDM side

And client side.


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Hardware Loopback

Client side

Transmitting module

Hardware

Software loopback

Loopback

Receiving module

Rx

Tx

WDM side

IN

OUT

Rx

Tx

IN

OUT

Fixed

Attenuation


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Reset Board

Reset SCC Board

Reset by NM.

Reset by Pressing the reset button on SCCboard.

Reset by removing and inserting SCC board

Reset Other Boards

Reset by NM

Reset by unplugging/plugging the board.


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Clean Optical Interface

Make sure the fiber to be cleaned is disconnected

with any active component.

Hold the fiber connector,clean the surface with lens

tissue, Do this once or twice more using differentparts of the tissue.

After the surface dries,use special compressed gas

to blow the surface

Check the connector surface


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Optical Power Test

OTM OTM

IN IN IN ININININ IN

ODF ODF

OTU OTUMUX/

DEMUX

OA FIUMUX/

DEMUXOAFIU

Optical power

meter

Optical power

meter

OUT

IN

Fiber

jumperTesting

port

Optical board

Testing

port

Optical board

Fiber

jumper

Optical power

meter

MON

Optical

Power test


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Replacement of Board

Before replacement

During replacement

After replacement

Check board version

(Especially for OUT)

Detailed information

Can be obtained from

Bar code.

Detailed information

Can be obtained from

Bar code.

Wear an ESD wrist

strap. Correctly

swap the board.

Avoid short-circuit of

the board.

Skilled at the operation methods in

General precautions.

The setting of board jumpers and

DIP switches.

Input optical power range of optical

Interface board;

Remove the optical fiber from the

front panel;Width of the front panel.

Prevent eyes from being hurt

by the laser.

Check whether the

board is working

normally, and upload

configuration on the

NM again.

If you replace the SCC board, you

shall upload the original SCC

configuration data to the NM, and

then download them from the NM to

the new SCC. Pay attention to NE

user configuration


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Classification of Board Replacement

Classification of

boardsBoard name Remarks

Optical transponder

unit

OTU For new OTU;a.The type is identical with the original one.

b.The wavelength, optical module is identical with that of the original

one

Optical amplifierunit

OA a. Prevent the over-high input optical power from damaging optical components.b. Keep the operating band of the new optical amplifier unitidentical with that of original one.

c. Do not stare into the output optical interface, since the output optical

power of HBA, PRA/RPC/RPL is very high.

Optical multiplexing/

Demultiplexing &

Add/drop multiplexingunit

MUX /

DEMUX

a. Prevent the over-high input optical power from damaging optical components.

b. Keep the operating band of the new optical amplifier unit identical with that

of original one.c. Keep the type of the substitute board identical with that of original one.

Optical supervisory

Channel unit

SC1, SC2

TC1, TC2a. The type of the substitute board identical with that of original one and whether

it supports LHP system application.

b. The input optical power


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Contents



Fault Locatiting




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Requirements for Maintenance Personnel

Be familiar with DWDM system and troubleshooting of common

alarms

Professional in Basic Operations

Familiarity with Common Test Instruments

Awareness of Network Layout

Collection and Saving of On-site Data


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Basic Principles of Fault Locating

Note: The key step is to locate the fault to a certain

cable or a station or an exact board accurately.

External First, then Internal

High-severity Alarms First,

then Low-severity Alarms

Network First, then NE

Why Trouble?


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Common Methods of Fault Locating

Alarm and performance analysis

Test with instruments

Replacement

Loopback

Handling based

On experience


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Alarm and performance analysis

Querying current or history alarms and performance data

through transmission network management (NM) system.

Querying current running status of the equipment through

Cabinet & board indicators

Features

From NMS

ComprehensiveThe fault information about the equipment in the

whole network can be obtained.

AccurateCurrent alarms, history alarms, occurrence time,And performance event data can be gotten.

Note:

If no obvious alarm or performance event is

reported, alarm and performance analysis is

useless.

From cabinet and board

Easy for operation on site

Faulty information is not detailed

How to obtain

alarms and

performance


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Test with instruments

Used to remove external problems of the transmission equipmentor interconnection problems

Test meters: optical power meter, optical spectrum analyzer, SDH

tester and signal analyzer.

1. Test MON port and measure optical

power, wavelength, OSNR directly, analyze

the gain flatness of the optical amplifierboard.

2. Compare with original data.

1.Compare with performance data from

NMS.

2.Avoid service interruption. MON port is

Recommended for measurement


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Replacement

SDH LWF

A

R_LOS

B

LWF reports R_LOS

Features

An abnormal article is replaced with a normal one. If the

problem still exists, it means that this particular article isnot faulty and there may be some other problems.

The article might be a section of fiber, a board, a flange

or an attenuator.


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Loopback

Tx1

Tx2

Txn

Rx1

Rx2

Rxn

Rx1

Rx2

Rxn

Tx1

Tx2

Txn

SDH

Analyzer

Attenuator

Attenuator

OM/OA OA/OD

OA/OD

OM/OA

Attenuator

s

Loopback by segments

or section

R_LOS


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Handling based on experience

Reset board

Plugging/unplugging board

Restarting a single station after power failure

Re-send configuration (SCC replacement)

It is recommended to use this method as less as possible, since

it is unsuitable for finding fault reason thoroughly.


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Troubleshooting Procedure

Troubleshooting for External Faults

Clearing the fault of accessed client equipment (SDH, Ethernet etc.)

Clearing the optical fiber fault

Clearing the fault of power supply

Clearing grounding fault

Locating fault to a single station

Locating the fault to a board Common methodReplacement, meter

test, and loopback

Loopback

Replacement


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Contents



Fault Locatiting Chapter 3 Fault Handling Flow



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Fault Handling Flow

General fault handling flow

Emergency handling flow

Collection and recording

information

Technical support

G l F l H dli


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General Fault Handling

FlowStart

Record fault symptom

External

Causes

Other handling

process

Analyze & locate fault

Fault

removed?

Feed back to Huawei

Work out solutions together

Try to solve

Service

recovery?

Running & observe

Fault

removed?

Yes

Yes

Yes

No

No

No

Fault

removed?

Summary and

Fitt out report

END

Yes

No

Yes


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Emergency Handling flowHandle service

interruption

Is standby channel

available?

Is loopback set?

Is there any abnormal

alarms?

Is optical powerabnormal?

Are there bit error

Do alarms below occur;

R_LOS/MUT_LOS

IN_PWR_LOW /

IN_PWR_HIGH

Switch the service to

the standby channel

Cancel loopback

Reset the board;

Remove/insert the board;

Replace the board

Optical powertroubleshooting

Bit error

troubleshooting

Contact Huawei for

help

Is the fault

Removed?

End

Transmission NM

2

1

4

5

3

NO

NO

NO

NO

NO

YES

YES

YES

YES

YES

YES

NO

NO YES

For service interruption

Caused by externalfactors

Such as power failure,

fiber Cut, improper operation

or software

And hardware faults


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Common Alarms and Causes

Board type

Optical

Amplifier Unit

MUT_LOS

Alarm Handling

Power related alarm, mainly relevant to the received signal. Check

whether the optical power of upstream optical path and station is normal.

PUM_BCM_ALM,

PUM_COOL_ALM

Check whether the running of fan is normal;

Check whether the ambient temperature is over-high or over-low ;

Board faulty. The board needs to be replaced.

Optical

Multiplexer/

DemultiplexerUnit

MUT_LOSPower related alarm, mainly relevant to the received signal. Check


LSR_COOL_ALM



Board faulty. If the service is affected, replace the board in time.

If not, replace it in a proper time.

OTU

R_LOS, IN_PWR_LOW

IN_PWR_HIGHPower related alarm, mainly relevant to the received signal. Check


R_LOF,B1_OVER,

B1_SD,B2_OVER,

B2_SD

Power related alarm, mainly relevant to the received signal. Check


In addition, if the module in the receiving end is faulty, these alarms willalso occur.

TF, OUT_PWR_LOW,

OUT_PWR_HIGH

Mainly relevant to the transmitting part of the board. If the service is affected, replace

the board in time.

OTU LSR_COOL_ALM,

LSR_WILL_DIE



Board faulty. If the service is affected, replace the board in time.

If not, replace it in a proper time.


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Technical Support

Vuppulamritha Magnatic Components Ltd.

Address: Plot No.3A, Road No. 2, Shakti Sai Nagar, IDA Mallapur,

R.R. Distt., Hyderabad, Andhra PradeshPostal Code: 500076

Website:http://www.vmcindia.com

Customer service mailbox: [email protected]
http://www.vmcindia.com/http://www.vmcindia.com/


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Contents



Fault Locatiting




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Fault Classification

Optical Power Abnormity

Bit Errors

Transient Service Interruption

Service Interruption

ECC Faults

Orderwire Faults

Equipment Interconnection Failure

Other Faults


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FAULT CLASSIFICATION



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SDH

SDH

SDH

SDH

OTU

OTU

OTU

OTU

OTU

OTU

OTU

OTU

SDH

SDH

SDH

SDH

MUX

MUX

OSC

DMUX

DMUXOA

OA

OA

OA

OSC

OTM OTM

Optical power checking point

Pay attenuation to

optical power of

OTU and OA

Category

Optical power

is too low

The input optical power is below the

Sensitivity.

Effect

Decrease of the input optical power

Affects optical signal-to-noise ratio.

The input optical power is below ALS

threshold.

Bit errors areGenerated.

Service is interrupted

Optical power

is too high The input optical power is above

Overload power

Bit errors are

Generated and optical

Receiving components

Are damaged.


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Fault type

External causes

Causes

Equipment faults

Fiber attenuation is too high (due to fiber bending, squeezing, binding

and dirty Connector).

Incorrect fiber connection

Line performance deterioration.

OUT board failure or performance deterioration.

Optical amplifying board failure or performance deterioration.

Alarm and performance analysisSection-by-section loopback

Replacement

Meter test

P d f H dli O i l P F l


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Is input optical power ofOBU abnormal ?

Procedure of Handling Optical Power Fault

StartIs input optical power of

OTU at Rx port abnormal ?

Adjust fibers between:- OPU/OAU

& DMUX; DMUX & OTU

11

33

2

13

12

11

10

9

88

77

66

5

44

Is output optical power of

OTU at OUT port abnormal ?


OBU abnormal ?

Is input optical power of FIU at

RC port abnormal ?

Is output optical power of FIU at

OUT port abnormal ?

Is input optical power of FIU at

IN port abnormal ?

Is output optical power of FIU at

TC port abnormal ?

Is input optical power of

OPU/OAU abnormal ?

Is output optical power ofOPU/OAU abnormal ?

Is input optical power of

OTU at IN port abnormal ?


OTU at Tx port abnormal ?

Is the received optical power of

SDH equipment abnormal ?

Remove the fault

At client side

Replace OUT

Adjust VOA placedBefore OBU

Replace OBU

Remove the

Fiber fault

Replace FIU

Remove the

Fiber fault

Replace FIU

Adjust VOA placed

Before OPU/OAU

Replace OPU/OAU

Contact

Replace OTU

Adjust fibers between OUT &

SDH equipmentIs fault

removed

End

NO

NO

NO

NO

NO

NO

NO

NO

NO

NO

YES

NONO

NO

NO

YES

YES

YES

YES

YES

YES

YES

YES

YES

YES

YESYES

YES

Transmitting

end

Receivingend

Transmission

NM

trouble shooting fault analysis

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