During configuration of client-side 1+1 protection on the OptiX OSN 6800, Working Channel Hold-Off Time (100ms) is set to 100. In this case, the protection hold-off time is too long and services are interrupted, the system reports the R_LOS alarm.
Symptom
After the fiber cable on the main optical path of the OptiX OSN 6800 in a network is broken, certain services in the IP bearer network are interrupted for 40 seconds.
Query the alarms of the OptiX OSN 6800 on the T2000. According to the query result, an R_LOS alarm is reported and a protection switching alarm is reported 10s after the R_LOS is reported.
Cause Analysis
The possible causes of the preceding problem are as follows:
- Protection switching on the DCP board is abnormal.
- There are excessive bit errors and therefore the performance of the optical path is degraded. In addition, the SD bit errors are not enabled as a trigger condition of switching.
- The protection hold-off time is inappropriate.
Procedure
- Query alarms on the NE by using the T2000. It is found that the R_LOS and CLIENT_PORT_PS alarms are reported.
- Query the attributes of client-side 1+1 protection on the NE. It is found that the protection hold-off time is set at the transmit and receive optical interfaces in the east direction between the NEs where the services are interrupted. Protection switching at the transmit and receive optical interfaces in the west direction is normal.
- Query the value of Working Channel Hold-Off Time (100ms) on the T2000. The value is 100. It is confirmed that the unit for setting the protection hold-off time is 100 ms. In this case, the value 100 indicates that the actual protection hold-off time is 10s. That is, protection switching is performed 10s after a switching-triggering alarm, such as the R_LOS alarm, is received. As a result, services are interrupted.
- Set Working Channel Hold-Off Time (100ms) to 1. Then the protection switching is normal.
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