Problem Description

OSN3500 and OSN7500 pairs are open for EPL service, configured with cross connects for VC4 and bound VC3 channel granules. Query overhead and find that the C2 overhead byte of the first VC3 in VC4 is unloaded, and the next two time slots are normal. When setting the C2 byte, the network administrator reports that the cross connection of the network element does not exist, with error code 38720. the same fault phenomenon exists at both ends of setting the C2 byte. the OSN3500 version is 5.21.12.42, and the OSN7500 version is 5.21.13.47.

Warning message

Network element cross-connection does not exist, error code 38720

Processing

1. circumvention solution: ensure that the cross routing and data veneer binding timeslot levels are consistent. For example, if EFS0 VCTRUNK1 binds VC3 time slots 1 to 3, then the crossover also establishes a crossover at the VC3 level.

2. Root solution: The host version of the network element is upgraded to R6 and above, and the time slot overhead configuration of the data veneer no longer has a check associated with the crossover configuration.

3, the scene through the circumvention program to successfully solve the problem of C2 and V5 overhead byte settings.

Root cause

1, the C2 and V5 bytes of the data veneer cannot be set in the case of no cross-configuration or inconsistent binding of cross-route and veneer VCTRUNK time slots in the R versions before R6. R6 and later versions no longer check whether the cross-links are configured or matched, and as long as the veneer is bound to the corresponding time slots, the C2 or V5 bytes can be set.

2, the current network EFS0 single board cross-link opened VC4 level, but the single board binding VCTRUNK is VC3 or VC12 time slot, so the single board binding time slot C2 and V5 bytes can not be set.

Recommendations and Summary

None