Symptom
An OptiX OSN 6800 network is configured with ODUk SNCP protection. One day, the customer reported that the network is not reverted back to the working channel after the network is restored from a protection switching. The optical fibers are normal. An ODU_SNCP_PS alarm is reported at the optical interface on the ND2 board. The NE software version is 5.51.4.24.
Cause analysis
The possible causes for reporting of the ODU_SNCP_PS alarm at the optical interface on the ND2 board are as follows:
l The optical fibers are faulty.
l The service configuration is abnormal.
l The ND2 board is faulty.
l An LCK signal is inserted, and therefore a protection switching is triggered by mistake.
Procedure
1. Check the receive optical power on the working and protection optical paths in the ring network. The result indicates that the optical fibers are normal.
2. Re-configure the services in the network and enable the services to pass through each station along the signal flow. The alarm persists.
3. Replace the ND2 board where the ODU_SNCP_PS alarm is reported. The alarm persists.
4. Collect and ***yze the fault data. It is found that the ND2 board also reports an ODU1_PM_LCK alarm, which is a minor alarm. In addition, the ODU1_PM_LCK alarm is also a trigger condition of an ODUk SNCP protection switching.
5. Set LCK Insertion of the board on the opposite site to Disabled for the board. That is, the ND2 board does not insert the LCK signal to the board on the opposite site. Then, the ODU_SNCP_PS alarm is cleared and the problem is resolved.
Result
The problem is resolved.
