Description of the problem

The fiber between the customer's existing network, ABIDA CITY, and MAAN BSC network elements was dug up due to road construction, and the 200-station service was interrupted after the reversal of the multiplexed segment.

Processing

1、Beijing time 18th around 19:10, 19:45 customer repair fiber, all services are fully restored.

2、According to the analysis of the returned data, it was found that the 9-59 network element should have been in the pass-through state during the fiber break reversal between ABIDA CITY and MAAN BSC, but the actual 9-59 network element was in the IDLE state, which led to the interruption of the service.

3. When the site restarted the multiplexing segment protocol, it was found that the east-west direction of the 9-59 network element was SF, and the network element was in the isolated state, and further inquired about the MSP enable state of the line veneer, which was not enabled, which would cause the line not to report the K bytes, and the multiplexing segment protocol thought that the east-west direction was in the SF, and so it went into the isolated state.

:optp:8,0,9b,1,08,b1,1,0

@@@@@@@@@@@@@@@@@ Message from 0x0009003b (9.0.59 589883) @@@@@@@@@@@@@@@@@@

Optp cmd : 08b1

01 00 00 //8 board line multiplexing segment not enabled

Total records :1

#9-59:test123 [9-59 Swaimah ][][2012-01-18 20:46:14+02:00]>

:optp:b,0,9b,1,08,b1,1,0

Optp cmd : 08b1

01 00 00 //11 board line multiplexing segment not enabled

Total records :1

#9-59:test123 [9-59 Swaimah ][][2012-01-18 20:46:21+02:00]>

4. By analyzing the line black box, the reason that the line veneer MSP enable state is the abnormal state of not enabled is that when the master control database was abnormal before, the host gave the line veneer an abnormal multiplexing segment configuration.

8-SLOT-n4sl64 single board:

TIME:2012-1-14 4:47:50 0xA9 08 EE 01 00 00 //The master set the single-board optical port attribute to non-MSP.

7-SLOT-n4sl64 Single Board:

TIME:2012-1-14 4:47:50 0xA9 08 EE 01 00 00 00 //Master set single board optical port attribute to non-MSP

5, by restoring the normal master control board database, soft reset cross single board and line single board, the master control board will re-distribute the correct configuration to the single board, and then carry out the reversal test of the multiplexing segment of each ring, the reversal state is normal, and there is no interruption of business.

To summarize, the abnormal business interruption of multiplexed segment inversion is due to the abnormal configuration data on the veneer side, while the abnormal configuration data on the veneer side is due to the abnormal sending of incorrect configuration data from the database of the main control board.

Root cause

The cause of the service interruption is the abnormal state of the 9-59 network element multiplexing segment during the fiber break MSP reversal, which is caused by the abnormal configuration of the multiplexing segment on the line board. The configuration abnormality on the line board can be traced back to the database abnormality caused by the warning problem during the upgrade of the network element last Saturday. When repairing the database anomaly, the database was not cleared and downloaded, and only the database recovery operation was performed on the main control board, which only repaired the main control database anomaly and did not repair the multiplexing segment configuration anomaly on the line board, resulting in an abnormal state of the multiplexing segment when it was inverted, and the protection did not take effect, which led to the interruption of the service.

Solution

Fundamental solution: When the database is abnormal, clear the database and download it.

Emergency Recovery Measure: Soft reset the circuit board and cross board when the database repair of the main control board has been completed.

This chapter of related technical information and SDH equipment troubleshooting process by the Shenzhen Optical Transmission Network Technology Limited collection (www.opticaltrans.com), reproduced please retain! Our company specializes in Huawei SDH optical transmission equipment, SDH transmission equipment sales.