Problem Description

A bureau OSN1500B composed of A-B-C chain type networking, A for the network management network elements, are configured with the master cross line unity board CXLLN, B network element optical module for the 622M rate, reported R_LOF, C network elements can not be online.

Alarm information

R_LOF

Processing

1, the upper-end B network element to C network element direction optical module is 622M, reported R_LOF, after checking the line attenuation is normal;

2、Suspect that the optical port of the lower-end C network element is configured as STM-1, but there is no STM-1 optical port in the upper-end network element.

3, the upper-end B network element to C network element direction 622M optical port deleted and added to STM-1 (no replacement of optical modules), R_LOF alarm disappears, the lower end of the C network element ECC normal;

4、After modifying the C network element optical module to STM-4, the C network element is de-regulated, and the B network element reports R_LOF again.

5, the B network element STM-1 optical port is deleted and added to STM-4, the R_LOF alarm disappears, and the C network element ECC is normal.

Root cause

This manufacturer's optical module is compatible with STM-1 and STM-4, which can remotely modify the optical port rate of the upper-end network element and dock with the lower-end without affecting the monitoring of the network element, and then modify the optical port rate of the lower-end network element to the required rate after docking, and then change the upper-end network element back to the required rate, which is suitable for the case of inconvenient to go to the site for debugging.

The manufacturer is: WTD

Solution

If there is no other STM-1 optical port at the upper end, modify the rate of the CXLLN port at the upper end (make sure that it will not be disconnected after modification), and then change the optical port at the lower end to the required rate after successful docking. (Only for STM-1 and STM-4 compatible optical modules)

Suggestion and Summary

This method is suitable for the case that it is inconvenient to go to the site for adjustment, and two conditions are needed: 1 ) there is no corresponding rate optical port at the upper end; 2 ) the optical module configured by CXLLN is compatible with STM-1 and STM-4; otherwise, only on-site adjustment can be made.