Fault Type:

Service Interruption
MUT_LOS
Optical Power Management

Symptom:

At the ROADM station consisting of the OptiX OSN 6800 V1R2, the signal flow in the
wavelength add direction is as follows: L4G->M40V->WSM9->OAU->FIU. After the internal
logical fiber connections are complete at the NE, create the single-station optical crossconnections
and select the automatic optical power adjustment function. Then, the T2000
prompts that the creation is successful. The OAU board, however, reports the MUT_LOS alarm.
No alarm is generated on other boards.

Cause ***ysis:


The OPA supports only the WSD9, WSM9, RMU9, and ROAM boards. In the case of other
boards supporting the setting of attenuation (VA1/M40V/D40V), the OPA does not set the
attenuation. Thus, you need to set the attenuation. During the calculation, OPA regards the
attenuation as zero (0) and the changes in the attenuation of the boards does not trigger the readjustment
by the OPA.
By default, the VA1, M40V, and D40V take the maximum attenuation for each channel. Hence,
when the OPA function is started, the light from the L4G does not enter the OAU after passing
the M40V because the attenuator of the M40V is not adjusted.


Procedure:

Step 1: Adjust the M40V on the T2000 and set the attenuation value of the corresponding channel to 0
dB. Then, the MUT_LOS alarm is cleared.


Reference Information:

In certain scenarios, the attenuation of certain channels of the M40V, D40V, VA1, and VA4
boards needs to be set manually. At the station that is configured with the M40V, D40V, VA1,
or VA4, set the attenuation value of the optical channel of the board manually to ensure the
availability of the optical channel. This is very important for the ASON feature to trigger
rerouting in the WDM network.

Guys, have it checked the case related to MUT_LOS alarm, its on transmit side.

Useful information!
Thanks for sharing.