|Source:||MSExchange Unified Messaging|
|Message:||The Microsoft Exchange Unified Messaging service was not able to redirect the call with ID “%1” to an available Unified Messaging Worker Process.|
This Error event indicates that the Unified Messaging Service was not able to redirect incoming messages received from the IP/VoIP gateway to the Unified Messaging (UM) worker process. The call with Call-ID specified in the event description was disconnected. The Unified Messaging Service first accepts the incoming Session Initiation Protocol (SIP) INVITE message over TCP sent by the IP/VoIP gateway. The service then tries to locate an available UM worker process (UMWorkerProcess.exe). If the UM worker process is ready to accept calls, the Unified Messaging Service will reply to the SIP INVITE message by using a 302 Moved Temporarily SIP response message. In this scenario, calls will be redirected and handled by the UM worker process. If the UM worker process becomes unresponsive or exceeds the lifespan, the Unified Messaging Service will retire the existing UM worker process, together with the resources it uses, and create a new UM worker process to handle any new requests. By creating a new process and redirecting calls to it, you can make the Unified Messaging Service more efficient and reliable, even when the original worker process that serves the requests has problems.
This event may occur if the UM worker process is started or shut down when the Unified Messaging Service tries to redirect a call. On rare occasions, this may occur after all UM worker processes stop unexpectedly.
To resolve this error, do the following:
If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.