Hello, everyone!
Today, I'd like to share a case with you!
Problem Description
A diamond ASON trail reported CPW_OCH_SER_SLADEG alarm.
Problem Analysis
WE check the OLP switching status on the A and B sites, the OLP port can normally receive optical power.
B site switching status is normal; A site switching status is abnormal.
We continue to analyze the NE logs of A, we found it has a RACK_CONFLICT_SCREEN alarm. (subrack ID conflict isolation alarm).
When the system detected it has a conflict subrack ID, the system will isolate all board on A_2, and report the RACK_CONFLICT_SCREEN alarm. (0x1 indicate that the conflict happened on 21-EFI board-Eth1 port)
For this network configuration, OLP bi-directional switching was configured on the 8-LTX and 14-OLP boards.
The bi-directional switching relies on APS protocol, the SCC board responsible to forwards the packets to the involved service boards.
After the A_2 sub-rack is isolated due to a conflict, the communication between the SCC board and the LTX&OLP board is abnormal.
As a result, the OLP board does not receive correct APS bytes from the peer end. Therefore, the OLP switching status of A_2 is abnormal.
Root Cause
The subrack ID conflict isolation alarm was not handled and the board in the subrack was not warm reset. As a result, the communication between the SCC board and other boards at site A_2 was interrupted, and the OLP switching status was abnormal.
Solution
1. Disable the 21-EFI -port. (refer to the screenshot below to disable the port.)
2. Warm reset all boards on the NE: A_2.
Welcome to leave a message!
Thank you!
