ptn product troubleshooting overview 30p

8/12/2019 PTN Product Troubleshooting Overview 30P

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Troubleshooting Overview

V1.0


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Course Objectives

To learn about precautions and requirements oftroubleshooting

To learn about methods of troubleshooting

To learn about tools and meters of troubleshooting


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Contents

Troubleshooting Overview Fault Location and Troubleshooting Principles

Fault Location and Troubleshooting Methods

Common Troubleshooting Tools and Meters

Troubleshooting Precautions and Requirements

Contacting Technical Support


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Troubleshooting ProcedureStart

Maintenance personnel find

device faults and alarms

To inform concerned

personnel to perform

troubleshooting

Fault solved?

To inform ZTE

technical personnel

Remote assistance

over phone

Fault solved?ZTE personnel

solve faults on site.

Device runs properly.

Faults are solved.

End

No

Yes

No

Yes


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Troubleshooting Flow

Analyze the failure and find out the failure type

Collect failure information

Determine the failure conditions

Record the troubleshooting process

Remove the failure

Locate the cause of the failure


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Fault Location Principles

Principles of fault location

Get rid of the external possible factors

such as broken fiber, switching fault or power problem

and then consider the transmission device problem.

Try as much as possible to locate the faulty station

precisely and locate the faulty cards.

In alarm analysis:

Firstly, analyze the high-level alarms and then the lower-level

alarms.

Usually, the higher-level alarms suppress the lower-levelalarms.


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Troubleshooting Principles

When processing device faults, abide by the principle of

Check, Inquire, Think, and Operate. Check:

Firstly check the device fault symbols carefully, such as fault position,alarm causes, severity, and harmful degree.

Inquire: After the fault symbols are observed, inquire the on-site personnel

whether anything directly causes the fault, such as data modification,file deletion, circuit board replacement, power failure, or lightning strike.

Think: According to the fault symbols and inquiry and associated with

experiences, make analysis and perform fault location, judge the faultposition and fault causes.

Operate: After finding the fault position through the previous steps, adopt

appropriate operations to solve the fault, such as modifyingconfiguration data, and replacing cards.


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Contents







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Collecting Failure Information Methods

In the case of a failure, the first thing we need to do is

collecting all information related to the failure.

The following summarizes basic methods of how to collect

required information related to a failure:

Check operation logs of related modules.

Use a packet catcher to collect packets.

Perform basic network tests

such as ping, telnet, and trace route.

Check operation logs including the operation logs of related service, the operating system, and dual

servers.

Check and analyze related alarms.

Perform tests on the actual service.


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Analysis by Observation Observing the alarm indicator status on the device

Analyze the various types of alarm events and performance datainformation on the device and NM

And make sure that the current running time setting of each NE in thenetwork must be consistent with the time on NM. Otherwise, it mayresult that the NE alarms, performance information collection is wrongand not in time.

Analysis Failure Code Diagnose software and service failures

Plug in/out Method When the fault is located on some card, the faults, such as bad

contact or abnormal card status, can be solved by plugging out andplugging in the cards and external interface connectors.

Note: strictly conform to regulations when plugging in/out cardslest that cards are damaged due to improper operations.


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Fault Location and Troubleshooting (Continue)

NM Test

When the networking , services and fault information are rathercomplicated, or special faults with no obvious alarms and performanceinformation reports, do not appear on the device, use the maintenancefunctions provided by NM to perform test, judge fault positions and faulttypes.

Loopback that requires no profound analysis on alarms and performanceis a common and most effective way to locate fault positions. However, it

affects services. Before loopback operation, first determine the NE, card, channel, and direction

because channels that get faulty at the same time have a certain relativity.When selecting loopback channels, select an NE from several faulty NEs andselect a service channel from several faulty service channels. Perform theloopback operation on the selected service channel direction by direction andmake analysis

In loopback operation, first divide the service procedure of the faulty service

channel, draw a service routing diagram, list the service source, destination,traversed NE, occupied channels and timeslot numbers, and then loop segmentby segment to locate faults. After faults are located on an NE, locate thepossibly fault cards by looping at the side of line and tributary. Finally,combining other processing methods, confirm the faulty cards and replace them.


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Replacement Replacement means to use a normal part to replace the suspected

abnormal part to perform fault location and fault troubleshooting.

Here the part can be a cable, a card or a device. Solve the fault on the external transmission device, such as optical

fiber, trunk cable, switch, and power supply device. If faults occur on the switch or trunk cable, exchange with other normal

channels. If the alarm position changes after exchanging, it indicates thatthe external trunk cable or switch is faulty. If the fault remains afterexchanging, the transmission may be faulty.

After the fault is located on a single station, perform troubleshooting onthe cards in this single station.

For example, if an alarm appear on an optical line card in some station, itis suspected that the sending and receiving optical fiber are inverselyconnected. Exchange the two optical fibers. After exchanging, if the alarm

disappears, it indicates that the optical fibers are connected inversely. Power and grounding troubleshooting

For example, the input power and grounding on some device aresuspected to be faulty, replace a channel of input power and groundingterminal to solve the fault.


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Configuration Data Analysis

Caused by device configuration changes or maintenance personnelsmistaken operations.

After locating faults on the NE in a single station, we can analyze faults byquerying the current configuration data and NM security logs on the device

The most commonly used method is Data Comparison Compare the difference between the faulty configuration data (or faulty device)

and the correct configuration data (or normal device)

Configuration Modification To solve the faults caused by configuration errors after faults are located

on a single station. Includes card slot configuration, card parameter configuration.

System Simplification Method Observe the simplest system after removing all the other irrelevant hardware

Notes: Because modifying configuration is rather complicated, it has a highrequirement for maintenance personnel. Therefore, it is applied only torestore services temporarily when the backup cards are not available, orapplied to locate the pointer adjustment. It is not recommended generally.


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Test by Meter

Test by meter refers to using tools and meters to test the work parameters of thedevice quantitatively, which is generally applied to solve the external faults of thetransmission device and the inter-connection fault of other devices.

If the power voltage is too high or too low, use a multi-meter to test the voltage.

If other devices fail to be connected, the device grounding is suspected to be faulty. Use amulti-meter to test the voltage value between the sending signal ground and the receivingsignal ground of the channel.

If other devices fail to be connected, it is suspected that the interface signal is notcompatible. Observe whether the signal is normal, or whether any exceptional alarms occur

by the signal analysis meter, and then judge the fault causes.

Processing by Experiences In some special cases, the device card works in an exceptional status, its services

are suspended, and NE communication is faulty due to transient abnormal powersupply, and strong external electro-magnetic interference.

Yet, the configuration data are completely correct. Proved by experiences, in this

case, the faults can be solved and services are restored timely and effectively byresetting cards, powering on the device again, and re-distributing configuration data.

Summarise Flexible combination of different methods is recommended when it is hard to

determine whether a failure is a software failure or a hardware failure.


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Contents







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Common Tools and Meters

Tape Screwdrivers

Diagonalpliers

Sharp

nose pliers

Antistatic

wrist strap Wire

stripper

40 W electrical iron

Crimping

Pliers

IC extractor

fiber-pigtail

jumper

Clamping

pincersPliers

Fiber

extractor

Adjustable

wrench


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Common Tools and Meters (continue)

Digital

multimeter

Optical powermeter

Other

Instruments

Meters

for

Environment

MonitoringOptical

attenuator


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Usage of Common Meters

Digital Multi-meter Usually we use a digital multi-meter to test the voltage, so we here

introduce how to measure voltage with a digital multi-meter.

To measure the DC voltage

1. Turn on the multi-meter.

2. Insert the black pen into the COM hole and the red pen into the V/ hole.

3. Set the functional switch to DC voltage position V- Measurement rangeand connect the pens to the power (to measure the open-circuit voltage)or load (to measure load voltage). The polarity of the red-pen-connectedterminal is displayed on the display.

To measure the AC voltage

1. Turn on the multi-meter.

2. Insert the black pen into the COM hole and the red pen into the V/ hole.3. Set the functional switch to AC voltage position V- Measurement range

and connect the pens to the power or load. When the AC voltage ismeasured, the polarity is not displayed.


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PMS-1A-Type Optical PowerMeter PMS-1A-type optical power meter

is used to measure theconsecutive optical signal power,displayed by LED.

It has the functions of auto-measurement range shift, auto-shutdown, auto-clearing, multi-

wavelength measurement, andrelative power measurement.

The work wavelength of the PMS-1A-type optical power is 1300 nm,1310 nm, 1480 nm, 1550 nm foroptions.

The measurement ranges from -40 dBm to +20 dBm (0.1 nW~100

mW). Its measurement accuracyis5%.

The probe interface type is FC.

The outline of the PMS-1A-typeoptical power meter is shown onthe right side.

Probe interface

LED display

Power switch

Relative measurement

status shift key

Clear key

External power

interface

Wavelength

selection

Unit selection

dBm

Unit selection WATT


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Select measurementunit

ON/OFF

Selectwavelength

Connect optical source

Select measurement

mode

Relative power measurement

Absolute power measurement

Select measurement

unit

Connect optical source

dBre1; enter into relative

measurement status

dBm key WATT key

dBm key WATT key

Read measurement result

PMS-1A-Type Optical

Power Meter The operation procedure of

the PMS-1A-type optical

power meter is shown on the

right side.


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PMS-1A-Type Optical Power Meter Precautions:

Be sure to charge the battery.

Cover the probes with a probe cover before clearing in casethat the light affects the measurement results.

In measurement, be sure to select appropriate wavelength formeasurement in correspondence to different optical interfaces.Select 1310 nm for I.X, S-X.1, and L-X.1 optical interfaces.Select 1510 nm for S-X.2, and L-X.2 optical interfaces. Xrepresents the level of SDH transmission signal (X=1, 4, 16, 64).

While using the meter, be sure to prevent humidity, shock, dust

and heat. Keep the probes and connectors clean. If the meter is long stored or used in a low temperature, be sure

to place it in a high temperature for a while before using lestthat the meter gets damaged due to freezing.


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YGBERT-2M-Type BitError Analyzer The YGBERT-2M-type bit

error analyzer is aportable, handset meter,used to detect bit errorsand alarms in the PCMdigital transmissionsystem, optical fibercommunication system,and digital microwave

communication system. It can detect 2Mbit/s of

rate level. Its codepattern generator inputcomplies with CCITTG.703 recommendation,allowing the lineattenuation between 0 dB- 6 dB.

It can be inserted withsingle-bit errors orperiodical bit errors. Ithas LED indication of thesignal suspension, AIS,asynchronization, and biterrors, and the function ofbuzzing alarm.

No signal

AIS

No sync

Bit Error

Start/Stop

Select

Setup

Tx Bit Error

G.821

BE/BER

Power

AIS

/

/

/

G.821

/

LED

display

Sending

signal

interface

Receiving

signal

interfacePrint

interface

Power

switch

Power-

on/Reset

No input signal alarm

indication

AIS alarm indication

Asynchronization alarm indication

Bit error alarm indication

Incoming/outgoing parameter modification

Meter parameter and status modification

Cursor move

Move/stop meter running

Bit error/bit error rate display

transformation

Display G.821

analysis result

Single-bit error

insertion key

External power

connection interface


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YGBERT-2M-Type Bit Error

Analyzer The operation procedure of

the YGBERT-2M-type bit

error analyzer is shown as

right chart:

Precautions:

Be sure to charge the battery

in time.

The batter run for 4 hours

after being recharged.

If you perform a 24-hour bit

error test, it is necessary to

use the external power

supply.

215-1 PRBS15

Turn on bit error analyzer

and connect to the device

Set the code patter 215-1

PRBS15

Start test

Preset test time

Stop test

Read test result


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Contents







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Precautions

Security warning

symbols

Note

Security Symbol Description

Note

Electric shock

Anti-static symbol

Corrosive symbol

Laser Symbol

Flammable Materials prohibited

No smoking

No touching

Security Symbol Description

Danger

Warning

If warning is ignored, it may cause

personnel death or device damages






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Be familiar with the following precautions and requirements before you

begin a troubleshooting procedure. Follow the safety regulations and precautions specified by the operator in

the equipment room during troubleshooting.

Before troubleshooting, back up service data and operation parameters.

During troubleshooting, collect all failure-related data for analyzing andfinding the failure cause, and record useful information in detail, for

example, failure symptoms, version information, and data changes. After troubleshooting, fill in the troubleshooting log to record all details of

the troubleshooting procedure. Add shift records to the log for thetroubleshooting that can not be completed in a day. Such troubleshootingmay involve different maintenance personnel.

Begin a troubleshooting procedure immediately when a failure occurs. If

you fail to remove a failure, contact your local ZTE office for support. Frequently update the contact information of your local ZTE office and

paste the latest contact information of your local ZTE office on an eye-catching place so that you can contact the local office in time in the case ofemergency.


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Be familiar with the following precautions and requirements when you

start a troubleshooting procedure: Be cautious of grounding and lightning protection and satisfy lightning

specifications for device grounding.

Troubleshooting precautions on optical interfaces

Dust-proof caps for optical interfaces are not available.

Do not stare at optical interfaces directly in case of eyes being harmed.

Troubleshooting precautions on cards Anti-static measures to prevent device damages.

Be careful while inserting cards.

Troubleshooting precautions on devices

Try not to perform power-off operations to guarantee non-breakabletransmission services after devices are put into use in view of the significance

of the transmission devices in network. Never perform installation and disassemble power cables when power is on as

it may cause electric sparks or electric arcs, and even cause fire or harm eyes.Before installation or power cable disassembly, turn off the power.


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Contents







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In the following cases, contact your local ZTE office for technical supportimmediately. Occurrence of a critical failures, for example, interruption of part or all services Occurrence of a failure that cannot be removed according to the instructions provided by this

manual

Occurrence of a failure that cannot be removed according to the handling methods you alreadyknow

Occurrence of a failure that cannot be removed according to your troubleshooting experience onsimilar failures

Before contact technical support, prepare the following information, which maybe required by ZTE support engineers. Failure details, including occurrence time, location, and failure symptoms

Log files on the server and the client

Data collected by a packet catcher

Details of the troubleshooting operations you have done

Remote login method, and the contact phone number

You can contact your local ZTE office for the following support: Field Support

ZTE maintenance engineers go to the field to troubleshoot the failure

Phone Support ZTE maintenance engineers guide the field engineers to troubleshoot the failure by phone.

Remote Support ZTE maintenance engineers log in to the system or equipment remotely to troubleshoot the failure.


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ptn product troubleshooting overview 30p

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