Fault Description:

Initially an R_LOF alarm was reported on the Rx port of LWF board within STM-64 MSP ring, and then iterations are observed in R_LOF alarm, and BEFFEC warnings, thereby triggering protection alarms/APS_INDI on OSN 3500 integrated with BWS 1600G, at Site A and Site B.

Alarm Information: None.

Causes:

The probable causes are as follows:

· Optical power degradation.
· Faulty patch cords/Dirty Patch cords.
· Faulty Attenuator (s).
· Faulty LWF board.
· Faulty SL64/Line board.


Procedure:

2. Check whether Optical power degradation observed at Rx/IN port of the LWF board.
3. Use OSA to check whether configured wavelength is being received from the Far end.
4. Replace existing attenuators (if any), to check if they are faulty or dusty.
5. Replace patch cords connecting IN/OUT port towards Mux/Demux boards.
6. Apply self-loop to the LWF board, by connecting IN port to the Out port (adding 7db attenuator is recommended), and apply another loop to IN port/Out port of the corresponding SL64/Line board (again adding 7db attenuator is recommended), and check if the R_LOF alarm and BEFFEC warnings are cleared.
7. If alarm persists even after applying self-loop at LWF board end, then replace the LWF board.
8. If alarm persists even after applying self-loop at SL64/SLD64 end, then replace the SL64/Line board.

Conclusion:

After executing all the troubleshooting steps, it was diagnosed, that corresponding LWF board or SL64 is faulty, and was replaced to clear all the alarms, and link became normal.

Suggestions:

All necessary troubleshooting tools and spares.

Hi Folks, i have updated my previous case, kindly review and comment.

Previous thread: http://support.huawei.com/huaweiconnect/thread-353673.html

Hope it helps resolve your queries. Let me for any further support.

Thanks for sharing

Thanks for writing in.

Thanks for the case, nicely written.

Thank You all for valuable comments, much appreciated!

it is greatly explained. thanks

Thank for sharing, but maybe i am not expert in this