Any single process instance failure does not affect service, with the possible exception of the call (context) being processed at the time of the failure. Each call context of a particular type is accessible by all process instances of that same type. If the last accessible process instance of a type fails on a node, the backup instances on the backup node take over. However, if the last accessible process instance of a type fails on the last active node, service is affected.
|Last Failing Process||Consequence|
|Universal Call Engine||All calls dropped with a loss of the last 30 minutes of CDRs.|
|CSTA Signaling Manager||All CSTA calls dropped and new call attempts denied.|
|SIP SM Manager||No more call processing.|
|CDR Handler||CDRs accumulate until process is restarted.|
|XDM||SIP calls blocked.|
For example, all Universal Context Engine (UCE) contexts are accessible by all UCE instances. If the last UCE instance on the last redundant node fails UCE contexts will be lost. But if a UCE fails during initial processing of a call this call may be affected as well.
Parent topic: Cluster Redundancy