Calls Directed to Exchange Unified Messaging Subscriber Access or Auto-attendant Do Not Connect
Microsoft Office Communications Server 2007 and Microsoft Office Communications Server 2007 R2 will reach end of support on January 9, 2018. To stay supported, you will need to upgrade. For more information, see Resources to help you upgrade your Office 2007 servers and clients.
If calls directed to Exchange Unified Messaging Subscriber Access or Auto-attendant do not connect, you can troubleshoot the issue as follows:
Verify that a subscriber access number has been defined on the SIP URI dial plan that is used with Office Communications Server, or that you have configured the auto-attendant that is associated with the SIP dial plan with a valid telephone number and enabled auto-attendant.
Verify that the Exchange administrator has installed a certificate from a CA that is trusted by both the Exchange Server 2007 servers and the Office Communications Server 2007 R2 servers.
Use the Exchange UM Integration Utility (that is, Ocsumutil.exe) to verify that contact objects are created for the Unified Messaging subscriber access and auto-attendant.
If the call passes through a PSTN gateway interface, verify that the gateway is configured to route the corresponding phone number to Exchange Unified Messaging.