In lab we created a Network Mesh between 4 ASON NEs naming NE1, NE2, NE3 and NE4. All connectivites were of STM-16 level. Diamond 1+1 service was created on this network adding on NE1 and dropping on NE2. Working path for that diamond service was from NE1-NE2. And protection path was from NE1-NE3-NE2. After creating that service it was also successfully tested. After that we created MSP 16 ring on NE1, NE2, NE3, NE4 and NE1. After fiber cut between working path and protection path of diamond service, it failed to re-route and get down.
After anlaysing it in lab we found one configuration problem. Actually Diamond services needs Un-Protected VC4s for re-routing. Otherwise services will not re-route successfully. When we created MSP STM-16 ring 16VC4 are now "Working" for MSP. When fiber cut happenes other 16VC4 goes in "Protection" status and there are no more "No-Protection" VC4s left for diamond re-routing. Hence resulted in service failure. It is not suggested to make MSP16 on STM-16 level connectivity when diamond services are involved.
Check the followings:
1) Make sure all the resources are available for re-routing diamond service
2) Make sure the service is created properly end to end.
3) Check the status of all TE links, Control channels, and LSPs
Never create the full utilization of MSP whenever there are diamond services involved. Always reserves no-protected VC4s for diamond services.