Description of the problem

An ASON network reports CP_TEL_PATH_MIS (Channel Status Inconsistency at both ends of the TE link) alarms on a certain day at sites B and C. The service associated with the alarm is a silver-level intelligent service layer tunnel from point A to point D with a complete path. The device version is 5.21.18.55, and the supporting intelligent version is V1R5C01B022. The networking diagram of the device is as follows:

Alarm Information

CP_TEL-PATH_MIS

The B-site alarm parameters are as follows:

Path=5,Board=7,Port=1,Local path state=10, and remote path state=0;

Site C alarm parameters are as follows:

Path=5,Board=12,Port=1,Local path state=10,and remote path state=0;

Processing

I. According to the alarm parameters you can get the following information:

1. Port 7-1 of site B is docked with port 11-1 of site A. Local path state=10 (i.e., static occupancy) for port 7-1 VC4:5 at the local end of site B, and remote path state=0 (i.e., idle) for port VC4:5 at the opposite end, site A, port 11-1.

2. Site C port 12-1 is docked with site D port 8-1. The local port 12-1 VC4:5 time slot state of site C is Local path state=10 (i.e., static occupancy), and the opposite end site D port 8-1 VC4:5 time slot state is remote path state=0 (i.e., idle).

Second, through the network management again to view the service layer in the customer side of the business, found that the silver-level service layer tunnel without any VC12 services, consulting the customer learned that the path of the business for the temporary scheduling services, channel use is completed above the VC12 service has been deleted in its entirety.

Since the customer first establishes a silver-level service layer tunnel from A to D when establishing the VC12 service from site A to site D, and deletes all the lower-order services in the tunnel after the service scheduling is completed but does not delete the corresponding service layer tunnels, the VC4-level bidirectional crossover is automatically generated at sites B and C when establishing the service layer tunnels from site A to site D. Therefore, the customer deletes only the VC12-level services after the VC4-level crossover remains at sites B and C, which causes sites B and C to generate the CP_TEL_PATH_MIS (Channel Status Inconsistency at Both Ends of the TE Link) alarm.

After the intelligent service layer tunnels corresponding to the alarms are removed, the CP_TEL_PATH_MIS alarms at sites B and C disappear, and the problem is solved.

Root Cause

The channel states at both ends of the TE link are inconsistent, and the possible causes are as follows:

1. Incomplete operation of reserved resources, one end is reserved and the other end is idle;

2. incomplete resource allocation or release operation, one end is occupied and the other end is reserved or idle;

3. an inadequate service conversion process, with static services at one end and intelligent services at the other;

Recommendations and Summary

Be sure to pay attention to the completeness of releasing resources when deleting tunnel services in the intelligent domain, otherwise it is extremely easy to generate alarms of inconsistent TE link timeslots at both ends due to cross residuals.

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