This content describes the phenomenon when SNCP protection inversion fails, the impact on the system, the possible causes, the tools required for troubleshooting the failure, precautions, and processing steps. During normal network operation, the working channel generates conditions that trigger protection inversion, but the service cannot be automatically inverted to the protection channel, resulting in service interruption.SNCP protection inversion failure causes service interruption. Possible causes: incorrect configuration of protection group parameters, incorrect single-board fiber connection, or hardware failure can cause SNCP protection inversion to be unsuccessful.

Problem Description

In the process of XX project factory inspection, according to the customer's business requirements, the SNCP service is configured, and in the process of testing service inversion.

One end is connected to the equipment with SDH analyzer, and one end is looped back in the network management on the PQ1 single board, unplugging the main fiber.

found that the service is interrupted.

1. Networking form, ring networking, in which OSN2500 10 units, OSN3500 three units.

2. Service configuration, SNCP, recovery type.

3.Test instrument SDH analyzer. Rate 2M, coding form HDB3.

Alarm information

Check the site where the inversion is unsuccessful and find the AU-LOP alarm.

Processing

1. Re-view the service and configure it according to the product manual. There is no problem with the service configuration, and the service configuration error fault is ruled out.

2. Re-view the settings of SDH analyzer, according to the guidance of SDH analyzer, the configuration of SDH analyzer is correct, the

SDH analyzer send and receive both ends are configured 2M rate, HDB3 coding form. Rule out the SDH analyzer configuration errors.

3. Use the pigtail fiber to change back to the single board with the alarm, the alarm disappears, to rule out single board failure.

4. Produce to see the version configuration of the whole network, found that the fault site of the two main control boards, the main main control board is the version of V1R10, the main control board.

Standby master board is the version of V1R8, the version of the two master boards are inconsistent, in the V1R10 version of the master board as a

When the V1R10 version of the main control board is used as the main control board, there is an AU-LOP alarm, and it is forced to switch to the V1R8 version of the main control board to be used as the main control board.

The AU-LOP alarm disappears and the SNCP switchover is successful. The AU-LOP alarm disappeared and the SNCP switchover was successful.

The SNCP switchover test is successful. The reversal time is within 50ms.

Root Cause

Analyze the reasons for unsuccessful service reversal tests as follows:

1. SNCP service configuration error.

2.SDH analyzer setting error.

3. Single board failure.

4. Mismatch between the versions of the network element boards, the high-level cross-capacity of the V1R10 is 40G, and the main control board of the V1R8 is 20G.

The crossover capacity is inconsistent. When the main control board of V1R10 is used as the main control board, and the main control board of V1R8 is used as the main control board, the cross-capacity of V1R10 is 40G, and the cross-capacity of V1R8 is 20G.

As the V1R8 version of the main control board has a lower cross-capacity than the V1R10 version, the cross-capacity of the V1R10 version is not the same as the V1R8 version of the main control board.

When the cross-over capacity is large, the phenomenon of unsuccessful SNCP reversal will occur, and the V1R8 master board is used as the primary master board.

When the V1R8 motherboard is used as the main control board, this situation will not occur.

Suggestion and Summary

1. In the process of opening the board, always make sure that the version shipped should match, and check the version of the whole network before testing it

whether the information is consistent. Before testing, make sure that the information on the whole network is consistent, so as to ensure the smooth running of the test.

The technical information related to this chapter and the SDH equipment troubleshooting process are provided by Shenzhen Optical Transmission Network Technology Co.( www.opticaltrans.com), please retain! Huawei SDH Optical Transmission Equipment,SDH Transmission Equipment Sales