C&C08 Huawei

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Copyright © 2006 Huawei Technologies Co., Ltd. All rights reserved.

Trouble Shooting


Objectives

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

Understand the normal flow and methods to deal with

trouble

Master how to orientate Hardware system’s and User

system’s trouble

Master the universal trouble shooting methods


Contents

1. Normal Flow & Method

2. User System & Hardware System’s Trouble

3. The Common Trouble Shooting Orientation Method


Basic Requirement For Operator Familiar with system and network

Master the instrument and meter equipment

Familiar with operation

Professional technique and skill


Normal Flow Collecting message

Obtain the original information as soon as possible

Judging trouble

Make sure the range and category

Finding out the trouble point

Find out the reason of the trouble

Eliminating the trouble

Eliminate the trouble and repair system according to the

suitable processing


Normal method

Analyzing original information

Alarm messages

Indicating light status

Dialing test

Instrument and meter equipment

Traffic statistics


Normal method

Dynamic & Signaling tracing

Test / Loop

Contrast / Interchange

Switchover / Reset

Contact with Huawei Support Technology


Normal method Analyzing original information

Example 1:

U (User): My phone has some problem, please help me to check it.

E (Engineer): When did you face this problem? Calling out or calling in.

U: Oh, calling in. I could hear ring-back tone when I used mobile to call my

phone set. But the phone didn’t ringing. What’s the problem?

E: Ok, Did you try to pick up the phone when you make a call? Could you

hear anything?

U: Yes, I tried it before. I just heard “Du…Du…”, and couldn’t talk with

each other.

E: You may have “Call forwarding unconditional” service. Could you dial

#57# to cancel it ?

Solve the problem


Normal method

Alarm messages

Example 2:We can observe the alarm messages by

Alarm Box and Alarm Station.


Normal method

Indicating light status Example 3:DTF card alarm indicating lights

If “LOS1” turn on, it means the first E1 Loss of

Signal. It may be disconnect or one-way audio.

If “SLP2” turn on, it means the second E1 slip frame.

It may be low clock synchronization performance or

high transmission attenuation.

Suggestion:

Operator should pay attention to accumulate

indicator’s status. It will help to improve the ability

of fleetly solving problem.DTF

CAS

LLB1

RLB1

RRA1

RMA1

SLP1

LOS1

RCL1

RUN

LLB2

RLB2

RRA2

RMA2

SLP2

LOS2

RCL2

DSP


Normal method Dialing test

Example 4: It is a new SS7 trunk group between Office A and opposite office. The trunk circuits and links status are normal. But they can’t use new trunk to make inter-office call.

Using a local office user to dial the opposite office number and tracing this user, observing the result is “No route available”. And don’t send “IAM” to opposite office.

Orientating: The route selection data has some problem and the system can’t choose suitable circuit.

Hint: Dialing test is used popular. It’s usually used with dynamic tracing.


Normal method

Instrument and meter equipment

Example 5: Most user’s CLIP service are abnormal in a certain

frame.

To judge the influence for CLIP of PWX card. Using oscillograph to

analyzing output ringing current wave shape. It’s contain many

“harmonic voltage”. First judging burr interference “FSK” sending

and make CLIP abnormal.

Suggestion:

If condition permission, can choose instrument and meter

equipment for trouble analysis. The key point is the correct using

for instrument.


Normal method

Traffic statistics Example 6: The office A create TG Incoming Office statistics. It cont

ains “Lost Calls Of Int Congest Times” 10 times in 500 call attempts an hour.

It has several reasons for “Lost Calls Of Int Congest Times ” . Creating the Fail reason traffic in total office traffic task, The “No Ipath times” and “No Available Circuit Times” amounts are the same.

Which module is congesting? To tracing SS7 link and observing the SEC message, the operator finds the problem in X module.

Check the iDT trunk circuit between X module and Central module, they find that some PCM system are self-looped.


Normal method

Dynamic & Signaling tracing Example 7: Office A connect to Tandem X. There are some CGC me

ssage between them. It has the influence for call completion rate. The link and circuits status are normal. Data setting is correct. The result of link tracing as below:

Tandem IAI IAI…. CLF CLF……

Local IAI IAI… (total:22 IAI) CGC RLG CGC RLG…… There are 22 IAI messages which contents are the same. The reason is L

ocal office A and Tandem setting the same prefix and make cyclic between each other.


Normal method

Test / Loop Example 8: Local office A connects to office B. It appears many E1 s

lip alarms that has serious influence between them. The Network structure of office B as bellow:

We can choose point ① 、②、③、④ for loop testing. According to compare with the result, we can orientate the fault which is belong to switch system of transmission system.

This method is used widely for transmission fault.

OFFICE AC&C08

DDF DDFOFFICE B

11 22 33 44

Transmission Transmission


Normal method Contrast / Interchange

Example 9: When make the test for rise digits in office X, some incoming call are rejected by system. The system send SST and the data setting is correct. The network structure as below:

According to dialing test: C can connect to B, but can’t connect to A. A & B call forwarding unconditional to D.

Compare with SS7 signaling, the “Redirected call indicator ” in IAI is 1 when C call A, since C call B is 0.

Change soft parameter. The system no need judge “Redirected call indicator ”, and solve this problem.

TandemTandem

USER A USER B USER C USER D

CC08CC08OFFICE XOFFICE X

TUPTUP


Questions

How many kinds of method we have learned for

trouble shooting?

Which kind of method did you use before?


Contents



3. The Common Trouble Shooting Orientation Method


Category of Hardware System Trouble Central Module

……CPMCPM

CCMCCM

CNETCNET

SPMSPM

SRMSRM

LIMLIM

LIMLIM

LIM-MHILIM-MHI

AAMMPP

CCDDPP

BBCCPP

FFSSNN

BBAACC

FFSSNN

……

SSPPCC

BBCCCC

CCPPCC

……

SSPPDD

SSRRCC

……

QQSSII

MMHHII

MMHHII

……

QQSSII

OOBBCC

EETT1166

……SSTTUU

QQSSII

OOBBCC

EETT1166

SSTTUU

……CCNNUU

BBDDRR

SSNNUU

SSNNUU

NNCCCC

SSNNUU

……

……

BAMBAMLANSWITCHLANSWITCH

TCP/IPTCP/IP TCP/IPTCP/IP

HDLCHDLC

HDLCHDLC

HDLCHDLC

HDLCHDLC

HDLCHDLC

393M393M

393M393M

393M393M

MHIHW-2M

MHIHW-8M

SM40.96M40.96M

E1E1 OPPOSITE OPPOSITE OFFICE OFFICE

The Fault of CardThe Fault of CardAnd internal connectionAnd internal connection

The fault of TCP/IP The fault of TCP/IP connectionconnection

HDLCHDLC

The fault of CCMHW The fault of CCMHW connectionconnection

The fault of MHIHWThe fault of MHIHW connectionconnectionThe fault of OFL The fault of OFL connectionconnection


Category of Hardware System Trouble Central Module

The fault of Card

The fault of Internal connection

The fault of TCP/IP connection

The fault of CCMHW connection

The fault of MHIHW connection

The fault of OFL connection

The fault of Clock Line connection

The fault of DIP switch

The different version of hardware and software


Category of Hardware System Trouble Switching Module

The fault of card

The fault of internal connection (NOD, HW)

The fault of OFL connection between Central Module

The fault of switches setting


Typical trouble case

Example 1:

Phenomenon Description: The 4# LIM can’t load in 128M.

Cause Analysis:

First to check the DIP switch (00000100), since the Frame ID

must keep the same as DIP switch.

Handling Process:

The 4# LIM DIP switch setting is incorrect when the operator

check it in the office. The 4# LIM begin to load after change

DIP switch.


Typical trouble case

Example 2:

Phenomenon Description: The SPM version can’t report after

loading.

Cause Analysis:

The data and program are loaded in SPC by TCP/IP. The SPC

communicate with other cards though CCMHW. If CCMHW setting is

incorrect, the SPC can’t communicate with other card and can’t

report the version.

Handling Process:

The SPC and BCC CCMHW should be 16,17,18, but the data setting

are 17,18,16. The SPM version can report after changing data setting.


Common reason and handling procedure in User System Trouble Typical case analysis and discussing

The common trouble phenomenon in User System

The common reason for User system trouble


Typical trouble case analysis

Example 1: no feedback

Phenomenon Description: The user can’t hear dial tone

after hook off. And the “work indicator” on telephone

turn off.

指示灯不亮Indicator

Turn off


Typical trouble case analysis Cause Analysis:

The external user line is short circuit or break.

The port which provided by ASL card is fault.

The external user line or analogue circuit is broken.

swinging cross.

The user’s phone set is broken

Suggestion and summary: The most trouble occur in

external user line or ASL card fault. It is necessary to test

external user line and ASL card regularly for preventing

trouble.

µ ½µ ×Ê ÇÊ ²Ã Ô Ò òÄ Ø£ ¿

What’s the

reason?



Example 2: CLIP service is abnormal

Phenomenon Description:

The phone set which apply the CLIP service can’t display

the caller number as called 。 The caller number display is fault. For example : the

number uncompleted, loss number or number error.

Why caller number disappeared?



Case analysis:

“can’t display the caller number” analysis:

– Check the FSK signal starting or not

– Check ASL card port is fault or not

– Check user’s phone set is fault or not

– Check user’s supplementary contains CLIP or not

– Check BNET(SM) or SRC(SPM) is fault or not



Case analysis:

“the caller number error” analysis:

– Check external user line

– Check ASL card port is fault or not

– Check BNET(SM) or SRC(SPM) is fault or not

– Check clock signal is normal or not

– Contact with “Huawei Technology Support”


Typical trouble case discussing Example for discussing 1: Ringing abnormal

Phenomenon Description :

No ringing. When make a call, caller can hear ring back tone, but

called don’t ringing. They can make conversation if called hook off.

Self-ringing. The phone will ringing itself even there isn’t incoming

call. When the called pick up, find is no incoming call here. The

ringing mode could be normal, long and so on.

Can’t cut off the ringing. Caller hear ring back tone, called ringing

then called off-hook. The called keep ringing and they can’t make

conversation.

What’s the possible reason?


No Ringing Analysis

No. Reason Remark

1 PWX is fault. No ringing

current.

There are no ringing current in User

Frame. It’s usually whole frame user

no ringing.

2 The supplementary

service is used

unsuitable.

The called set “CFU” and doesn't

cancel in time. It brings on all of the

call transfer to other user.

3 The circuit for ringing is

fault.

The corresponding user can’t

ringing.


Self-ringing Analysis

No. Reason Remark

1 The user ling in ASL is fault.

Ring relay start-up

unconventionally or can’t

release after startup.

The user will be self-ringing or

ringing for long time.

2 The power supply is unstable.

It contains harmonic wave.

It makes ASL ring relay start-up

error and the user self-ringing.

3 The software running

procedure is abnormal.

It makes ASL ring relay start-up

abnormal and the user self-

ringing.


Can’t cut off the ringing Analysis

Reason: The loop resistance is larger than switching

system monitor range.

Criterion: The loop resistance in free status ≤1800Ω; The loop resistance in

off-hook status≤300Ω. If switching system can’t detect the off-

hook, the called party will be considered free and the system will

send ringing current continually.

Summary: This kind of trouble occurs in village almost. It can solved by

change external user line or augment external user line’s core

area. And can use the better remote feeding ASL card to solve

this problem also.


Typical trouble case discussing

Example for discussing 2: The half of frame or whole

frame users are fault

Phenomenon Description :

The phone set is no feedback, and can’t call in

No dial tone

Noise is great in conversation

What’s the possible reason?


The possible reason-1

No

.

Reason Remark

1 The mother

board fuse is

burned

If fuse F1,F2 are burned, it will no feedback in whole

frame.

2 The mother

board is fault

Can’t call in and the noise is heavy in conversation.

3 DRV card is

fault

The DRV can used for receive DTMF, transfer user

line signal and drive HW signal. It usually used for a

pair. If one is broken and another card can’t start-up

help function, the half or whole frame’s users will

can’t hear dial tone, can’t call in or can’t work

normal.


The possible reason-2

No

.

Reason Remark

4 NOD card is

fault

NOD likes communication bridge between MPU and

other cards. If NOD is broken, the whole frame user

can’t hear dial tone and can’t call in. If half of NOD is

broken, the call loss will be higher in user frame.

5 HW connection There are 2 HWs in each user frame. If one of them is broken, since help function can’t start-up, It occurs no dial tone, heavy noise and one-way audio in half of frame. It will affect whole frame if serious.

6 NOD connection If NOD line disconnect, it will bring on calling loss,

increasing no dial tone times and so on.


The summary of user system phenomenon-1Range Category Phenomenon

Single user No feedback No dial tone

Ringing abnormal No ringing, self-ringing, can’t cut off ringing

Call in abnormal Can’t call in, can’t conversation, just ring one

time

Call out abnormal No dial tone, can’t cut off dial tone, hear busy

tone when pick up the phone

Connect

abnormal

Intra-module, Inter-module, Inter-office connect

abnormal

Conversation

abnormal

Noise is loud, the voice is small or loud, cross-

talking

CLIP abnormal No display, display error, display incomplete

Different

range user

Half frame of

whole frame

No feedback, can’t call in, no dial tone, heavy

noise, CLIP service abnormal and so on.


The summary of user system phenomenon-2Range Category Phenomenon

Different

range

user

Whole office

congestion

All of the trunks disconnect, the system can’t

process any incoming and outgoing call. Or all of

the modules can’t call each other.

Inter-module

congestion

The user in SM, RSM, SPM can’t make

conversation between other modules.

Intra-module

congestion

The user in SM, RSM, SPM can’t make

conversation in the same module.

Intra-module

connection abnormal

one-way audio, can’t make conversation, disconnect when make conversation.

Inter-module or inter-

office connection

abnormal

Connection cost long time, one-way audio, can’t

make conversation, disconnect when make

conversation.


The summary of user system trouble reason-1

Categor

y

Reason Remark

External

user line

disconnect/

short circuit

No feedback, no ringing, can’t call in, no dial tone

Grounding Loud noise, dial wrong number, ringing abnormal

Swinging

cross

No feedback, no ringing, self-ringing, no dial tone, can’t cut

off dial tone, display caller number error, the voice is small

Hardware ASL card fault No feedback, ringing abnormal, noise in conversation, the

voice is small, display caller number abnormal

DRV card

fault

No dial tone, can’t cut off dial tone, hear busy tone when

pick up the phone, usually affect a half of frame

PWX card

fault

No ringing, loud noise, display caller number abnormal,

usually affect a half of frame

NOD card

fault

No dial tone, can’t call in, usually affect a half of frame or

whole frame


The summary of user system trouble reason-2

Categor

y

Reason Remark

Hardware SIG card fault No dial tone, usually affect one module

BNET card fault Intra-module connection abnormal, If clock phase

abnormal, it will appear noise in conversation,

disconnect when surf in network, display caller

number abnormal

HW line fault No dial tone, no ring back tone, one-way audio

NOD line fault No dial tone, can’t call in, usually affect a half of frame

Clock line fault noise in conversation, disconnect when surf in network

or in conversation, usually affect a half or whole frame

Other

reasons

Didn’t define user

data

No dial tone, can’t call in

Phone set fault No feedback, dial wrong number, ringing abnormal, noise in conversation, the voice is small, one-way audio

CIC no matching Outgoing call one-way audio,


Summary

What did we learn in this chapter?

We have described hardware system and user system

trouble shooting in detail.

We have learned the trouble phenomenon, cause

analysis and handling process in hardware system and

user system.


Contents



3. The Common Trouble Shooting Orientation

Method


The Common Trouble Shooting Method The category of common trouble

Trunk/Link system common trouble

Charging/Bill management common trouble


Trunk/Link system

Trunk/Link system data setting ADD CALLSRC

SET OFI (ADD OFI)

ADD N7DSP

ADD N7LKS

ADD N7RT

ADD SPMN7LNK

ADD OFC

ADD SRT

ADD RT ADD N7TG

ADD SPME1

ADD RTANA

ADD CNACLD

ADD CPCCFG

ADD SPMN7TKC

Pay attention:Pay attention:OPCOPCDPCDPCCICCICSLCSLC

TKC selection mode…TKC selection mode…



Case 1: No.7 link status abnormal

Trouble phenomenon:

Disconnect. Viz. the link can’t locate.

The link is unsteady. Namely the link always Initial

alignment and can’t transfer MSU.

The link interdiction, viz. remote processor outage.

The link is congestion. Namely the link works overload.

What’s possible reason?



The possible reason:

Transmission fault

STP fault

ET16/STU/DTF card is fault

Remote processor outage

Data setting incorrect (DPC/SLC/Link selection code)



Case 2: SS7 Trunk circuit status abnormal

Circuit status Remark

Fault If trunk circuits are not blocked when DPC unreachable

or PCM system fault, the trunk circuit status is fault.

Available blocked That indicates blocked opposite circuits already. It can

make outgoing call but can’t accept incoming call in

these status.

Unavailable blocked That indicates blocked local circuits already. It can

accept incoming call but can’t make outgoing call in

these status.

Unknown When office sends RSC/GRS message for this circuit

and doesn’t receive RLC, it will change to this status.

Uninstall That indicates didn’t configure trunk data yet. What’s possible reason?



The possible reason-1:

No. Reason Remark

1 Transmission

disconnect/error code

Circuit status “fault”

2 ET16, STU, DTF card

fault

3 Data configuration

incorrect or didn’t do

it

If didn’t configure trunk data, the circuit

status is “uninstall”. If didn’t configure DPC

or make mistake, the status is “fault”.

4 CPU overload and

start-up congestion

control

“Available block”



No

.

Reason Remark

5 BLOCK

6 CIC no matching “Unknown”

7 Link fault If DPC unreachable, the circuit status is

“fault”. If link congests or has high error

rate, the circuit status is “unknown”.

8 Local side hardware

fault

“Unavailable block”




Case 3: The SS7 signal cooperation abnormal

Trouble phenomenon:

The SS7 signal cooperation abnormal usually means

inter-office connection abnormal. Like can’t make

conversation.

The caller number send abnormal. The incoming office

can’t obtain caller number or can’t obtain the real caller

number.

What’s possible reason?




CIC no matching

The corresponding data for caller number is incorrect

Like “can request caller number”, “request caller

number”, “connect without or with invalid caller

number”, “default number”, “CLI provision mode”.

The call barring data is incorrect

The barring group number, the caller discrimination

number and so on.




The supplementary signaling setting unsuitable

Like “send caller number”, “translate caller number”,

“send original called” setting unsuitable, then can’t

carry out some supplementary, such as CLIP, CLIR, call

forward and so on.

The soft parameter setting unsuitable


Real case analysis

Example 1: When user in Fix Network Office A call

mobile user, the caller number can’t carry area code.

The trouble phenomenon:

The network structure is as below. When user who is in

Fix Network call mobile user, the caller number need

carry area code in gateway office. All of users are carry

area code normal, except in office A.Office AOffice A

MobileMobile OfficeOffice

Office BOffice B

A,CA,C

USER AUSER A

USER BUSER B

USER CUSER C

B,CB,C0755B,C0755B,C

A,CA,C

Gateway OfficeGateway Office


Real case analysis Handling Process:

Using signaling tracing in gateway office, compare with A->C IAI and B->C IAI message. The “Nature of address indicator” is “00”(Local number) in B->C IAI message. And the “Nature of address indicator” is “10”(National significant number) in A->C IAI message.

Let office A change parameter “Nature of address indicator” to “00”, the caller number turn to normal.

Cause analysis: The parameter “Nature of address indicator” in signal which is sent by of

fice A is incorrect. Although the caller number doesn’t carry area code, the “Nature of address indicator” is “10”(National significant number). The gateway office considers the toll call and no need append area code.


Charging/Bill management system Charging/Bill management system

Charging operation

Charging analysis

Caller Caller CalledCalled

ADD/MOD STADD/MOD ST ADD/MOD CNACLDADD/MOD CNACLD

ADD CHGIDXADD CHGIDXADD CHGANAADD CHGANAMOD CHGMODEMOD CHGMODE

DETAIL

METER

BAMBAM

RST BILPOLRST BILPOL

STR BILIFSTR BILIFMPU/SPCMPU/SPC


Real case analysis Example 1:

Phenomenon: When use ISP mode to carry out “simultaneous ringing”, the user B regist

ers “simultaneous ringing” to user C. If the user A who comes from opposite office call user B through incoming TG, system charge incoming TG. B and C ring at same time. If B picks up the phone, system generate one incoming TG ticket for A-B. If C picks up the phone to make conversation, there isn’t incoming TG ticket in system. It must generate incoming TG ticket for A-B, ether B picks up or C picks up.

Office COffice C

Office AOffice A

USER AUSER A

USER CUSER CA,BA,B

C&C08C&C08

USER BUSER B

A,BA,B

A,CA,C


Real case analysis

Example 1: Cause analysis:

It must generate incoming TG ticket for A-B, ether B picks

up or C picks up in ISP mode for “simultaneous ringing”.

Pay attention: If C pick up the phone, according to

incoming TG charging source code and the charging

selection code in prefix for virtual PBX indicating number,

system analyze charging case. It may be that the charging

data for prefix of virtual PBX indicating number is incorrect.


Real case analysis Example 1:

Handling Process:

When check charging data, the data setting is no charging

for corresponding incoming TG charging source code and

charging selection code of virtual PBX prefix. After change

the charging case to detail ticket, the charging is normal.

When A dial B, the B and C ring at same time. The system

generates incoming TG ticket successful for A-B, ether B

picks up or C picks up.


Real case analysis

Example 2:

Phenomenon:

The BAM couldn't fetch bill tickets from the exchange

since some day. There were no new *.bil generated

since that moment, and the total amount of bill tickets

in the SPM (there was only one SPM module in this

office, no SM) was more than 20,000.

Creating file in D:/bill/bill is fault

DETAIL

METER

BAMBAMSTR BILIFSTR BILIFMPU/SPCMPU/SPC

RST BILPOLRST BILPOL


Real case analysis

Example 2:

Cause Analysis:

After checking the billprint.txt, operator found the reason

as follows. >2005-11-29 10:45:53 Failed to open or create

ticket file (filename d:\bill\bill\2005112814.BIL) So the

problem was on the BAM. The following needs to be

checked.

1. Disk space on the BAM

2. Disk quality

3. If the attribute of folder bill has been set as read only

mode


Real case analysis

Example 2:

Handling Process:

After contacting the on-site engineer, he said that the

customer did something yesterday afternoon. Finally he

found that the folder Bill was set as read-only mode. The

problem was solved after changing folder Bill to writable

mode.


Summary In these course, we have learned:

Normal flow and method for trouble shooting

The hardware and user system trouble phenomenon,

cause analysis and handling process.

Some common trouble shooting orientation method

Thank youwww.huawei.com

C&C08 Huawei

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