OptiX OSN 1500

OptiX OSN 1500

Failure Category

• Device Interfacing Failure
• Service Interruption
• LP_RDI

Phenomenon Description

During network expansion and remodeling, the SLQ1 single board of OptiX OSN 1500 equipment is directly docked with the router optical card of Company C. The network is protected by 1+1 linear multiplexing segments, with 2M services at one end and 155M optical port services at the other end. The network is protected by 1+1 linear multiplexing segments, with 2M services at one end and 155M optical port services docked at the other end, in which 2M services report LP_RDI alarms.

Cause analysis

Check the optical transmission path, time slot docking, router hardware, and SDH single board overhead mode one by one to troubleshoot the problem.

Steps

1. After the physical connection is normal, the SLQ1 board and the optical port of Company C receive normal optical power, and there is no optical power alarm at the receiving end, but the link status of Company C's router shows down.
2. Query the alarm and find that there is no abnormal alarm on the SLQ1 board, but the 2M service at the other end reports the LP_RDI alarm.
3. Loop back internally to the docking optical port of the SLQ1 single board, and the LP_RDI alarm of the 2M service disappears, indicating that the optical transmission path is normal.
4. In the outer loop back to the docking optical port of the SLQ1 single board, the link status of Company C's router is displayed as up, and it is suspected that the time slot is incorrectly docked.
5. Check the first VC-12 bearer service in VC-4 of SLQ1 board, which corresponds to the first VC-12 bearer service of Company C. The link status of Company C's router shows up, and it is suspected that the time slot is incorrectly connected. Corresponding to the 2nd VC-12 of Company C, add a 2M service on the 22nd VC-12, and the remote 2M service still reports LP_RDI alarm, suspecting that the local end fails to receive optical signals.
6. Reset the router, and the fault remains after reboot.
7. Check the SDH service configuration. The docking optical port of the SLQ1 board at the local end was originally a VC-4 service, and after deleting the VC-4 service, a new VC-12 service was added, and the overhead mode should be "Termination". Query the corresponding overhead mode, and it is still "pass-through". After setting it to "Termination", the LP_RDI alarm disappears and the service is normal.

Reference Information

When configuring low-order services, the high-order overhead of the circuit board must be set to "Termination", otherwise the services will be interrupted.