Huawei HG8245T Router Manual PDF (Setup & Configuration Guide)

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Alarm Information

l

Loss of GEM cells

l

Recovery of GEM channels

l

Deterioration of ONU signals

Cause Analysis

The ONT is connected to the OLT through optical fibers directly. As a result, the receive optical

power of the ONT is very large, which is beyond the normal range of optical modules. Therefore,

the cycle from the loss of optical signals, to the recovery of optical signals, and then to the

deterioration of optical signals repeats.

Procedure

Step 1

Check the optical fiber connection and it is found that the ONT is directly connected to the OLT

through an optical fiber. Therefore, the optical power for the transmission between the OLT and

the ONT may be excessively high.

Step 2

Add an optical splitter between the ONT and the OLT. After the ONT is registered, the alarm

disappears.

----End

Suggestion and Conclusion

An ONT cannot be connected to an OLT directly. Optical attenuators or optical splitters must

be added between them to ensure that the optical path attenuation ranges from 15 dB to 25 dB.

NOTE

The specifications of the optical path attenuation are as follows:

l

The optical attenuation on the GPON port on the ONT should range from 15 dB to 25 dB.

l

The optical attenuation of an optical fiber is about 0.3 dB per kilometer.

l

After optical signals travel through an optical splitter, the attenuation of the optical signals is as follows:

l

3dB if the splitter is a 1:2 optical splitter.

l

6 dB if the splitter is a 1:4 optical splitter.

l

12 dB if the splitter is a 1:16 optical splitter.

l

15 dB if the splitter is a 1:32 optical splitter.

l

18 dB if the splitter is a 1:64 optical splitter.

TC-C6052 Login to the ONU Through the Maintenance Network Port for

Deployment Upgrade Fails Due to the Mismatch of the ARP Mapping

This topic describes how to troubleshoot the fault when login to the ONU through the

maintenance network port for deployment upgrade fails due to the mismatch of the ARP

mapping.

Fault Type

Host service

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

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Keyword

ARP mapping

Maintenance network port

Fault Description

The ONU (MA5620E) is connected to a PC with the IP address 10.11.104.1/24. Login to the

ONU from the PC through default maintenance network port 0/1/1 fails, and the IP address

10.11.104.2/24 of the ONU cannot be pinged through from the PC. Through the serial port,

however, login to the ONU is successful.

Alarm Information

None

Cause Analysis

l

The board of the ONU is faulty.

l

The maintenance network port of the ONU is incorrectly configured.

l

The network configuration of the PC is incorrect.

Procedure

Step 1

Log in to the ONU through the serial port. It is found that the boards of the ONU are in the

normal state.

Step 2

Query the configuration of the maintenance network port of the ONU. It is found that the

configuration is correct.

Step 3

Query the status of the maintenance network port. It is found that the maintenance network port

is in the normal state.

Step 4

Query the ARP table on the PC. It is found that the MAC address corresponding to 10.11.104.2

is 00-18-82-77-1c-c0, which is different from the MAC address 0018-8277-1d02 of the ONU.

This is the cause of the fault. The MAC address corresponding to 10.11.104.2 is the MAC address

of the previous ONU rather than the current ONU.

C:\Documents and Settings\Administrator>

arp -a

Interface: 10.11.104.1 --- 0x2

Internet Address

Physical Address

Type

10.11.104.2

00-18-82-77-1c-c0

dynamic

Step 5

Run the

arp -d

command to delete the previous ARP mapping. Login to the current ONU is

successful, and the fault is rectified.

----End

Suggestion and Summary

Generally, a mapping in the ARP table is automatically invalid five or ten minutes after the

mapping is not used. Before the previous mapping is invalid, login to the current ONU from the

PC fails.

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

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TC-C6054 Data Cannot Be Saved on the MxU Because the H.248 Interface Is Not

Registered

This topic describes how to troubleshoot the fault when data cannot be saved on the MxU because

the H.248 interface is not registered.

Fault Type

VoIP service

Keyword

H.248 interface

Data saving

Fault Description

During the data saving on a new deployed ONU (MA5620E), it is found that the system prompts

a saving failure when the saving process reaches 90%.

Alarm Information

None

Cause Analysis

l

The CPU usage is high when the system executes certain tasks, which results in the saving

failure.

l

The H.248 interface is abnormal.

Procedure

Step 1

Query the CPU usage before running the command for saving data. It is found that the CPU

usage is normal. Therefore, the fault is not caused by the high CPU usage.

Step 2

Through multiple tests, it is found that when data saving fails, the H.248 interface is in the down

state; when data saving is successful, the H.248 interface is in the up state.

Step 3

Query the configuration of the H.248 interface. It is found that the transmission mode of the H.

248 interface is

alf/udp

. After the transmission mode is modified to

udp

, data can be saved

regardless of whether the H.248 interface is in the up or down state.

NOTE

When the transmission mode of the H.248 interface is configured as

alf/udp

, the status of H.248 interface is

detected because

alf/udp

has the transaction reliability function. With this function, when the H.248 interface

is not registered, the system regards the H.248 interface as abnormal, and therefore does not allow the data

saving.

----End

Suggestion and Summary

During the deployment, when the MxU is configured, it is recommended that the MG interface

be configured with the

udp

transmission mode. After the MxU runs in the normal state, the

alf/

udp

transmission mode can be selected.

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

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TC-C6120 Many Users Under the Same PON Port Have Dialing Error 678 Because

Optical Power Is Too Strong

This topic describes how to troubleshoot the fault when many users under the same PON port

have dialing error 678.

Fault Type

ONU

Keyword

Too strong optical power

Dialing error 678

Fault Description

Network topology: PC -> ONU (MA5616) -> OLT (MA5600T) -> BRAS

Fault description: Four ONUs (MA5616s) are connected to a PON port. Since deployment, all

users under some ONUs or under all ONUs connected to the PON port have been reporting

dialing error 678. The ONUs with dialing error 678 cannot be logged in remotely. In addition,

the ONUs cannot be pinged from the OLT.

Alarm Information

None

Cause Analysis

l

The ONU is faulty.

l

The optical splitter is faulty.

l

The PON port on the OLT is faulty.

l

The optical path is faulty.

Procedure

Step 1

Because all ONUs under the PON port have this fault intermittently. Therefore, it can be

determined that the fault is not caused by a single ONU.

Step 2

Replace the optical splitter with a new one. It is found that the fault persists. Therefore, it can

be determined that the fault is not caused by the optical splitter.

Step 3

Connect the ONU to the PON port on another board of the OLT. It is found that the fault persists.

Therefore, it can be determined that the fault is not caused by the PON port of the OLT.

Step 4

Check the optical path. The distance from an ONU to the OLT is about 1700 m. The measured

Rx optical power on the primary PON port of the optical splitter is about 2 dB; the measured Rx

optical power on each ONU port is about -6.3 dB. As indicated in documentation, the Rx optical

power of the PON port on the ONU should be from -8 dB to -24 dB. However, the Rx optical

power of any of these ONUs exceeds -8 dB. Therefore, the optical power may be too strong.

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

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Step 5

Add a 5 dB optical attenuator on the primary PON port of the OLT. Then, the measured Rx

optical power of the ONU becomes about -12 dB. Observation for about a week shows that none

user under the PON port reports dialing error 678 again. That is, this fault is rectified.

----End

Suggestion and Summary

If the optical power is very strong, the ONU cannot receive optical signals normally.

TC-C6307 A Large Number of Alarms Are Generated on the OLT Because the

Optical Power for the Transmission Between the OLT and the ONT Is Excessively

High

This topic describes how to troubleshoot the fault when a large number of alarms are generated

on the OLT because the optical power for the transmission between the OLT and the ONT is

excessively high.

Fault Type

GPON service

Keyword

Optical Power Is Excessively High

Fault Description

The ONT (HG850) can be registered but the alarms reported continuously on the OLT side.

Alarm Information

The alarms of GEM cell loss, GEM channel recovery, and ONU signal attenuation are reported

continuously on the OLT side.

Cause Analysis

l

The ONT is faulty.

l

The optical path is faulty.

Procedure

Step 1

Check the optical fiber connection and it is found that the ONT is directly connected to the OLT

through an optical fiber. Therefore, the optical power for the transmission between the OLT and

the ONT may be excessively high.

Step 2

Add an optical splitter between the ONT and the OLT. After the ONT is registered, the alarm

disappears.

----End

EchoLife HG8010/HG8240B/HG8245T/HG8247T GPON

Terminal

Service Manual

5 Maintenance and Troubleshooting

Issue 01 (2011-10-18)

Huawei Proprietary and Confidential

412

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