Hi,
When a cucm server loses connectivity with the other server in the server the following alert is seen
Error Message
CCM_CALLMANAGER-CALLMANAGER-1-SDLLinkOOS : SDL link to remote application is out of service Remote Application IP Address [String] Unique Link ID [String] Local Node ID [UInt] Local Application ID [Enum]Remote Node ID [UInt] Remote Application ID [Enum]
Explanation This alarm indicates that the local Unified CM has lost communication with the remote Unified CM. This alarm usually indicates that a node has gone out of service (whether intentionally for maintenance or to install a new load for example; or unintentionally due to a service failure or connectivity failure).
Recommended Action In the Cisco Unified Reporting tool, run a CM Cluster Overview report and check to see if all servers can communicate with the Publisher. Also check for any alarms that might have indicated a CallManager failure and take appropriate action for the indicated failure. If the node was taken out of service intentionally, bring the node back into service.
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/err_msgs/8_x/ccmalarms801.html
If you have anything specific going on in your network please share the details about the same.
Manish
