Description of the problem

A customer is experiencing business interruption during self-replacement of an OSN3500 device, slot 11 N2SL16 single board, host version 5.21.18.50P01

Processing

1, collect data and find that the network element id of the operation is 1677, and its 11-slot SL16 single board is in the 3-point multiplexed segment ring (1677---4005---1682).

2, by analyzing the K bytes, the actual multiplexing segment node number on the cross side of the 1682 network element is 2, so the multiplexing segment node numbers of the 1682 and 4005 network elements are the same, so the multiplexing segment inversion fails and the service is interrupted. However, the query on the network management as well as the command line query on the host side of the 1682's multiplexed segment node parameter is 1, how can this situation arise?

1682 network element K bytes, this network element sends 0x0120, so the 1682 network element cross-side node number is 2. The westbound node number is 1, and the eastbound node number is 0.

1 889 K_SENDS 0x0120 2014-07-16 01:56:08 0x035a3df1

1 890 K_DIR 0x0000 2014-07-16 01:56:08 0x035a3dfa

1 891 K_SENDS 0x0020 2014-07-16 01:56:08 0x035a3e60

1 892 k_dir 0x0002 2014-07-16 01:56:08 0x035a3e68

4005 network element K bytes, this element sends 0x0120, so the 4005 network element cross side node number is also 2. The westbound node number is 1 and the eastbound node number is 0.

6 55 K_SENDS 0x0120 2014-07-16 01:56:07 0x01f5519a

6 56 K_DIR 0x0000 2014-07-16 01:56:07 0x01f551a1

6 57 K_SENDS 0x0020 2014-07-16 01:56:07 0x01f55239

6 58 k_dir 0x0002 2014-07-16 01:56:07 0x01f55240

The node number on the host side of the 1682 network element is set to 1. The host command query is as follows:

#0x90692:cfg-get-rmsattrib:1;.

MSSPR-PG-ATTRIBUTE

PG-ID LOCAL-NODEID WEST-NODEID EAST-NODEID WTR-TIME

1 1 0 2 600

Total records :1

3, analyze 1682 network element master 18 single board BB1 has the following records. It indicates that the modification of the node number was made on 2011-09-28 17:08:03 (GMT time), and the old node number is consistent with the cross-side node number.

2011-09-28 [17:08:03] 0x0001 UserId:2;PgId:1;OldNode:2(L),1(W),0(E);NewNode:1(L),0(W),2(E)

4, it can be seen that the multiplexing segment node id of 1682 has indeed been modified, and it should be judged that the communication abnormality of the network element during the modification of the multiplexing segment node id of 1682 network element has resulted in the node number information not being sent down to the cross-side.

5, further localization found that a number of single boards have reported comfail alarms, we suggest that the user replace the AUX single board and reset the multiplexing segment node id of the 1682 network element, and then do the multiplexing segment inversion test is normal, and the problem is solved.

Root Cause

A network element communication anomaly while modifying the 1682 network element multiplexing segment node id resulted in the node number information not being sent down to the crossover side, which led to conflicting node ids on the multiplexing segment ring, and the multiplexing segment ring-to-swap failed.

Solution

1, replace the 1682 network element AUX single board, to solve the network element board communication problems.

2, modify the node number of the multiplexing segment of the 1682 network element, and correctly configure the parameter information of the multiplexing segment.

3, do the multiplexing segment inversion test is normal, replace the 1677 network element 11 slot SL16 single board successfully.

This chapter of related technical information and SDH equipment troubleshooting process by Shenzhen Optical Transmission Network Technology Co. Huawei SDH Optical Transmission Equipment,SDH Transmission Equipment Sales