Dslam Ma5600 Fault

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Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved.

DSLAM MA5600/MA5603/MA5616 Troubleshooting ADSL Service

Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Page2

Objectives

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

Analyze and locating the ADSL service Fault.

Eliminate the ADSL service fault.


Contents

1. Fault Analysis and Locating

2. Fault Categorized Troubleshooting

3. Case Study


Contents



3. Case Study


ADSL Fault Analysis

Let’s have a try to analyze the ADSL system fault by layered

and segmentation method

User side

Internet

Line

PPPoE

IP layerLAN

Port

Network side

IP layer, DNS, FTP, HTTP

PC Modem/CPEDSLAM


Website Internet BAS DSLAM Subscriber line Modem PC

Narrowband fault Attenuation Noise Line bridge Poor longitudinal balance

Port can not be activated Hardware fault Connection rate is low Data configuration

User account Protocol PC fault Application software fault

Fails and cannot be activated Powered off Unconnected Splitter fault

ADSL Fault Analysis (Cont.)

What’s the possible fault in each segment?


ADSL Fault Analysis

What’s the possible fault in each layer?

Physical

Data Link

Network

Transport

Session

Presentation

Application

Cable defected, board failure, cable disconnected…

PVC, VLAN, PPP link fail…

Destination unreachable, …


ADSL Fault Check

DSLAM BASModemPC MDF

30％ 10％60％

The probability and location of the xDSL service faults

MDF


ADSL Fault Check

Check CPE

Check PC and Modem

Check line

Check line quality through MODEM,DSLAM or test system

Check line connection

Check DSLAM

Check board/port/interface status

Check alarm/logs/debug information

Check configuration /version


Check Modem

Mode

Bridge

Routed

PPP

PVC

0 VPI/VCI

1 VPI/VCI

2 …

LED

POWER

ADSL LINK ACT

LAN LINK ACT

The mode should match the configuration in MA5600 or BRAS

The PVC VPI/VCI value should match the Configuration in MA5600

The Link LED should be on and ACT LED should always flicker


Check Modem

the physical line rate


Check Line Operation Parameter

MA5600(config-if-adsl-0/11)# display line operation 0– -------------------------------------------------------

– Channel mode : Interleaved

– Downstream channel bit swap : Enable

– Upstream channel bit swap : Enable

– Trellis mode : Enable

– Standard in port training : G.DMT

– Downstream channel rate(Kbps) : 6144

– Downstream max. attainable rate(Kbps) : 7264

– Downstream channel SNR margin(dB) : 18

– Downstream interleaved channel delay(ms): 4


Check MA5600

Class State Object

Board

Active –Normal / Standby-Normal SCUB

Auto_find / Config / Normal /

Failed / ProhibitService boards

PortActivating / Activated / Deactivated xDSL ports

Online / Offline Ethernet ports

Interface Up / Down Vlan-interface

Configuration Line-profile / Traffic table / VLAN / Service-port / PVC


Check Board

Query board status

Whether some board is fault. If yes, please record the board

type and the version.

MA5600#display board 0– ------------------------------------------------

– SlotID BoardName Status SubType0 SubType1

– ……

– 5 H601ADEE Failed

– 6 H601ADEE Normal – ……


Check Logs and Alarms

Query system logs

Obtain the information on operations performed by different

users

MA5600(config)# display log all

Query system generated alarms

Acquire the alarm information

MA5600(config)#display alarm history { alarmsn<K>|all<K>|

alarmid<K>|alarmlevel<K>|alarmtype<K> |alarmclass<K>|

alarmtime<K> }:


Contents



3. Case Study


Categorized Common Fault

Internet Service Failure with Abnormal Voice Service.

Internet Service Failure with Normal Voice Service.

Very Slow Access.

Unstable Access Rate or Frequent Interruption.


Categorized Fault Troubleshooting

Internet Service Failure with Abnormal Voice Service

Analysis:

You should ensure normal phone call and then analyze the internet

service fault ,the possible faulty concerned with this phenomena

should be:

– Bad line conditions

– Engineering mistake connection

Solution:

Report to line test center

– Test by line test system

– Check the line by segmentation manually



Internet Service Failure with Normal Voice Service

Analysis:

The broadband access server

The ADSL/ADSL2+ port

The ADSL/ADSL2+ MODEM

The user terminal

The physical line

Data configuration in MA5600

……



Internet Service Failure with Normal Voice Service (cont.)

Solution:

Check status and indicators on MODEM

– LAN problem

– Is Modem is SYNC with DSLAM?

Check PPPoE phase

– Configure Modem into BRIDGE Mode

– Perform PPPoE dialling through Windows Dial Up Connection

– Check the Error after PPPoE dialling ends



Internet Service Failure (cont.)

Solution: (Cont.)

If PPPoE dialling failed due to Error “678”

Check Status of Line Board (ADEE/ADGE/ADLE): i. If LED “RUN” & it is periodically ON & OFF during Period of “1s” then Board is normal. Then

problem could be due to one of below issue:

– Service Port is not created on DSLAM

– Wrong VLAN or PVC:VPI/VCI configuration on DSLAM

– Wrong PVC:VPI/VCI Configuration on MODEM

– Wrong Configuration of H.S.I VLAN on Transmission OR on BRAS

ii. If LED “RUN” is ON & OFF during period “0.5 s” then replace Line Board

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Internet Service Failure (cont.)

If PPPoE dialling failed due to Error

“691”

The error is caused by the wrong ID or password of the subscriber.

Initialize the information about the subscriber or set a new password to

solve this problem.

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Categorized Fault TroubleshootingUnstable Access Rate or Frequent Interruption

Analysis:

This fault is generally caused by bad line conditions, relatively long

line, or loop.

IP dialer

Splitter

Telephone extension

PC

AudioModem

xDSL Modem

Telephone set

Telephone line

Fax

PhoneModem

Line


Unstable Access Rate or Frequent Interruption

• Unstable Access rates or Frequent interruption of Internet is mostly due

to the outer loop lines fault.

• The issue of Access Rates or Frequent Interruption can be resolved by

to improving following most important Line Stats/Parameters:

i. SNR Margin

ii. Attenuation

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SNR MARGIN (dB)• SNR Margin could be thought of as a "buffer zone" which is there to protect your connection

against normal SNR fluctuations that can and do occur on a daily basis.

• If your SNR Margin is two Low, this may lead to slower throughput or frequent disconnections.

6dB or below is bad and will experience no synch or intermittent synch problems

7dB-10dB is fair but does not leave much room for variances in conditions

11dB-20dB is good with little or no synch problems* (but see note below)

20dB-28dB is excellent

29dB or above is outstanding

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ATTENUATION:

• Line attention is in relation to the "loop loss" on line.

• it means loss of signal as distance increase.

• The further you are away from the exchange the higher your attenuation figure will be

as the signal loss increases.

20dB and below is outstanding

20dB-30dB is excellent

30dB-40dB is very good

40dB-50dB is good

• 50dB-60dB is poor and may experience connectivity issues

60dB or above is bad and will experience connectivity issues

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Section Wise Testing for Localizing Slow Browsing Issue

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Bypass the Transmission & BRAS

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Bypass the DSLAM

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Dial up connection









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Dslam Ma5600 Fault