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Knowledge Base

The SDH Board Interconnected with the TOM Board Reports an R_LOS Alarm due to the Optical Module Fault of the TOM Board

Publication Date:  2019-07-05  |   Views:  179  |   Downloads:  0  |   Author:  SU1001580823  |   Document ID:  EKB0000375661


Issue Description

During the deployment of the OSN 6800, the SLQ4 board of the OSN 3500 interconnected with the TOM board reports an R_LOS alarm. The alarm is removed after an optical attenuator is attached to the SLQ4 board, but the self-loop alarm of the TOM board persists. 

Alarm Information


Handling Process

1. Suspect that the optical interface is faulty. Replace the optical interface of the TOM board. The alarm persists.
2. Configure bidirectional services between the Rx/Tx and the client on the TOM board. The alarm is removed.
3. After a consultation with Huawei experts, it is found that the optical module of the TOM board used during deployment is provided by other vendor. If no services are configured, the optical board does not report an R_LOF alarm but reports an R_LOS alarm when it receives an all-0s or all-1s signal. To solve this problem, configure services for the TOM board. 

Root Cause

The optical module of the TOM board is faulty.