Huawei HG8245T Router Manual PDF (Setup & Configuration Guide)

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Procedure

Step 1

When the "ONU frequently goes online and offline" alarm is generated, check whether the OLT

generates the following alarms. If such alarms are generated, clear them and check whether the

fault is rectified. If the fault persists, proceed to

Step 2

.

The following alarms may be generated:

l

0x2e11a001 The feed fiber is broken or OLT can not receive any expected optical signals

(LOS)

l

0x2e112007 The distribute fiber is broken or OLT can not receive expected optical

signals from GPON ONT(LOSi)

l

0x2e314021 There are illegal incursionary rogue ONTs under the port

l

0x2e314022 The ONT is rogue ONT

l

0x2e112002 The loss of GEM channel delineation (LCDGi) occurs

l

0x2e112003 The signal degrade of ONTi (SDi) occurs

l

0x2e112004 The signal fail of ONTi (SFi) occurs

l

0x2e112006 The loss of frame of ONTi (LOFi) occurs

Step 2

Check for the possible causes on the OLT and troubleshoot the faults accordingly. If the ONU

still fails to function properly after that, proceed to

Step 3

.

Possible Cause

Judgment Criterion

Troubleshooting Method

The PON port is faulty.

If either of the following two

situations occurs, the PON port

is faulty.

l

Run the

display port state

command to query the

status of the PON port. It is

found that abnormal items

exist in the query result. For

example, the laser status

(

Laser state

) is abnormal

and the transmit optical

power (

TX power

) exceeds

the normal range (1.5-5.0

dBm).

l

Migrate the service to

another port. It is found that

the ONU functions

properly.

Replace the optical module of

the PON port or replace the

board.

The board or the slot is

faulty.

All the ONUs connected to a

board frequently go online and

offline.

Change the board to another

slot. If the fault persist, replace

the board.

Step 3

Check for the possible causes on the ODN and troubleshoot the faults accordingly. If the ONU

still fails to function properly after that, proceed to

Step 4

.

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

Huawei Proprietary and Confidential

373

Page 382 / 429

Possible Cause

Judgment Criterion

Troubleshooting Method

The optical fiber

connector is not clean.

NOTE

An unclean optical fiber

connector will cause

excessive attenuation and

abnormal reflection.

1.

Test the backbone fiber and

branch fiber by using the

OTDR. It is found that the

reflection and return loss

are abnormal.

2.

Check the optical fiber

connector on site by using

the optical fiber endface

detector. It is found that the

optical fiber connector is

not clean.

Clean the optical fiber

connector. For details about

how to clean the connector, see

Cleaning the Connector of an

Optical Fiber.

The optical fiber is bent

excessively.

NOTE

Optical signals attenuate

seriously on an optical

fiber with an excessively

small bending radius.

1.

Test the backbone fiber and

branch fiber by using the

OTDR. It is found that

abnormal return loss points

exist on the optical fiber.

2.

Check the optical fiber on

site. It is found that the

optical fiber is bent

excessively.

Route and bundle the optical

fiber in a proper manner.

The optical fiber is not

firmly connected or

different types of optical

fiber connectors are

interconnected.

NOTE

If the optical fiber is not

firmly connected or

different types of optical

fiber connectors are

interconnected, the

attenuation and reflection

will be excessively large.

1.

Test the backbone fiber and

branch fiber by using the

OTDR. It is found that

abnormal return loss points

exist on the optical fiber.

2.

Check the optical fiber

connectors on site. It is

found that the optical fiber

is not firmly connected or

PC connector (blue) and

APC connector (green) are

interconnected.

l

If the optical fiber is not

firmly connected, reconnect

the optical fiber firmly.

l

If different types of optical

fiber connectors are

interconnected, replace the

incompatible connector

with a compatible one or

replace relevant devices,

such as the optical splitter.

NOTE

In the scenario of the CATV

service, it is recommended that

you use APC connectors (green)

only.

The multi-mode optical

fiber is used as the

backbone or branch

optical fiber.

NOTE

If the multi-mode optical

fiber is used as the

backbone or branch optical

fiber, the optical signal

attenuates quickly and the

return loss increases.

1.

Check the backbone fiber

and branch fiber by using

the OTDR. It is found that

optical signals attenuate

seriously.

2.

Check the optical path on

site. It is found that the

multi-mode optical fiber is

used. The multi-mode

optical fiber can be

recognized by its physical

features such as its color.

Replace the multi-mode optical

fiber with the single-mode

optical fiber.

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

Huawei Proprietary and Confidential

374

Page 383 / 429

Possible Cause

Judgment Criterion

Troubleshooting Method

The optical splitter is

faulty or the connectors

on the optical splitter are

not clean.

Measure the input and output

optical power of the optical

splitter by using the optical

power meter. It is found that the

actual attenuation exceeds the

theoretical attenuation.

NOTE

The faults in the optical splitter

cannot be located by the OTDR

because the OTDR cannot

penetrate the optical splitter.

Replace the faulty optical

splitter or clean the connectors

on the optical splitter.

The ODN is not properly

planned.

NOTE

l

The split ratio of the

ODN link is not

determined by the

number of ONTs

connected but by the

split ratio of optical

splitters. When an

optical splitter is

connected to the ODN,

attenuation occurs and

the split ratio of the

optical splitter needs to

be calculated.

l

Protocols specify that

the receive optical

power of the OLT

should not exceed 15

dB. In addition, the

difference between the

maximum optical

power and the

minimum optical

power should not

exceed 15 dB.

The ODN does not meet the

requirements of the ODN link

plan or GPON Class B+.

l

Three-level splitting exists

in the ODN.

l

The network coverage of

the ODN exceeds 20 km by

far.

l

The split ratio exceeds the

maximum split ratio that the

board allows. Assuming

that the maximum split ratio

of a board is 1:64. If the

first-level split ratio is 1:8

and the second-level split

ratio is 1:16, the actual split

ratio is 1:128, which

exceeds the maximum split

ratio of the board.

l

The optical attenuation

difference of two optical

paths exceeds 15 dB.

Optimize the ODN to meet

Huawei's ODN planning

requirements and protocol

requirements.

Step 4

Check for the possible causes on the ONU and troubleshoot the faults accordingly. If the ONU

still fails to function properly after that, proceed to

Step 5

.

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

Huawei Proprietary and Confidential

375

Page 384 / 429

Possible Cause

Judgment Criterion

Troubleshooting Method

A rogue ONU (such as a

continuous-mode ONU)

exists on the network and

affects other ONUs.

NOTE

If a rogue ONU exists, the

ONU that fails to go online

may be a normal one and

the ONU that can go online

may be a rogue one.

If either of the following two

situations occurs, a rogue ONU

exists.

l

The 0x2e314021 There are

illegal incursionary rogue

ONTs under the port alarm

is generated on the OLT.

l

The 0x2e314022 The ONT

is rogue ONT alarm is

generated on the OLT.

l

Connect the optical fiber of

the OLT port to the optical

power meter for

measurement. It is found

that the optical power is

greater than -45 dB. This

indicates that a continuous-

mode ONU or irregular-

mode ONU exists.

Replace the rogue ONU with a

normal one.

The ONU is restarted

repeatedly.

Check whether the ONU is

faulty or whether the power

voltage is unstable.

Replace the ONU or ensure that

the power supply of the ONU is

normal.

Step 5

Record the results of the preceding steps in the form for reporting a fault, fill in the form

completely, and then submit the form to Huawei for technical support.

Step 6

The fault is rectified.

----End

5.7.2 Troubleshooting the FTTH Service (OLT + HG Series ONT)

This chapter describes how to troubleshoot common faults in Internet access, multicast (IPTV),

and voice (VoIP) services in the GPON access mode in FTTH scenarios. Home gateway (HG)

series ONT includes the HG810a.

Troubleshooting the Internet Access Service

This topic describes how to troubleshoot common faults in the Internet access service, including

the following faults: PPPoE dialup failure, DHCP dialup failure, failure to access the Internet

after successful dialup, Internet access service interruption, and low Internet access rate.

Prerequisite

The ONU and the OLT must communicate with each other normally. If a fault occurs in

communication between the ONU and the OLT, all the services of the ONU are interrupted.

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

Huawei Proprietary and Confidential

376

Page 385 / 429

NOTE

The following lists common faults in communication between the ONU and the OLT.

l

ONU Registration Failure

l

Failure to Auto Discover an ONU

l

ONU Frequently Goes Online and Offline

?.1. Troubleshooting the Failure to Access the Internet

This section describes how to troubleshoot failures when users access the Internet on fiber to

the home (FTTH), for example, users fail to open Web pages.

Fault Location

Use the following guidelines to locate the fault.

Fault Location

Location Analysis

Possible Causes

User terminal

A user fails to obtain the IP

address (excludes users

with a static IP address).

For the details about how to troubleshoot

this fault, see the following sections:

l

PPPoE Dialup Failure

l

Failure to Obtain an IP Address in

the DHCP Mode

The user obtains the IP

address successfully

(excludes users with a

static IP address). The user

can access the Internet

after replacing the PC.

l

The user's PC is infected with viruses.

l

Internet Explorer (IE) on the user's

PC is faulty.

l

The network interface card (NIC) in

the user's PC is faulty, or the PC is

slow to respond after running for a

long period.

Web site

Certain Web sites fail to

open.

The Web site sever is faulty.

No Web site can be

opened.

The domain name server (DNS) fails to

resolve the IP address.

DNS

A Web site can be opened

by entering its IP address.

l

The DNS is faulty and fails to resolve

the domain name.

l

The communication between the

user's PC and the DNS is abnormal.

CAUTION

To facilitate fault report, save the results of the following steps.

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

Huawei Proprietary and Confidential

377

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