A ring consists of four OptiX OSN 6800s, namely, sites A, B, C, and D. The service boards are the NS2 and TDG, and the ODU1_SNCP protection is configured. When an operator removes the optical fiber between sites A and B to perform a switching test, the operator finds that the two GE services in two directions between sites A and B are interrupted and that the switching fails.
1. Query the status of the protection group of the service on NE A. The working and protection channels of the protection group are in the SF status.
2. Query the current alarms on NE A. It is found that alarms ODU2_PM_LCK and ODU1_PM_SSF are generated on the NS2 in the protection direction on the NE.
3. Query the overhead setting on the NS2. It is found that LCK insertion is enabled on the NS2 in the protection direction on NE A.
4. An LCK byte maintenance signal is used to lock the signal at the user access point during a test according to the requirement of the service carrier. It can be generated by the adaptation source and sink at the service layer. When LCK insertion is enabled, the value of the STAT byte at the PM layer is 101, and an LCK alarm is reported.
This alarm is a condition of SF. The protection group in the protection direction of NE A is in the SF state. If the optical fiber is broken in the working direction, switching of the protection group fails.
5. After LCK insertion is disabled, alarms ODU2_PM_LCK and ODU1_PM_SSF are cleared. Query the status of the protection group of the service. It is found that the protection group on the protection channel is normal. Remove the optical fiber again. The switching is successful. The problem is solved.
1. The protection channel is unavailable.
2. The service configuration is incorrect.
3. The logical fiber connection is incorrect.
4. Other problems.
An LCK byte maintenance signal is used to lock the signal at the user access point during a test according to the requirement of the service carrier. Enabling LCK insertion affects the services and the status of the protection group in the existing network. Do not enable this function unless it is necessary.