Fiber cut between two nodes resulted in service interruption in an MSP ring, though there was no SF or SD condition in any other section of the ring. APS_INDI alarm appeared along with R_LOS alarm on one node but the second adjacent node didn't show APS alarm. Force switching was done but the problem didn't resolve. When we tried to get MSP status from T2000, attributes of one node (ID:X) couldn't be queried. Corruption of K1 and K2 bytes causes the switching to fail and nodes parameters cannot be queried.
The problem can be handled and resolved doing the below mentioned operation:-
1. Query (cfg-get-rmsstate) and (cfg-get-rmsprotocol) from active EXCS board.
---->If cfg-get-rmsstate returned unsuccessfully , it means the active EXCS board has no correct rms configuration.So we should soft reset the active EXCS board(it will get data from SCC again), then query the rms state
-------->if it can return correctly, then do MSP switch test.,if everything is ok, do the same operation to the standby EXCS board(because only active EXCS board responds the “cfg-get-rmssate”, so remember to switch the EXCS board after soft reset).
-------->if it cannot return correctly,then one has to download the configuration by T2000, then query the rms state again, if return correctly, then do the MSP switch test else change GSCC board and then download configuration.
The reason was:-
---->There was no MSP switching event found on this node.
----> K1 and K2 bytes i.e. switching bytes are corrupted.
It was found that problem occurred due to the 24 bytes memory block overwrite problem. These overwrite the class’s v-ptr which reset the SCC on saving the database and finally cause the configuration database abnormal. After that some of the configurations like enable MSP protocol didn’t send to EXCS Board. The 24 bytes block was based on dynamic allocate memory, then we changed the method to static allocate which could solve this problem.
--->Query the MSP parameters during routine maintainence.
--->Upgrade Network nodes from 188.8.131.52 to V100R003C02B032SP01 version This version has static allocation of memory.