If missed calls are not connecting to Exchange Unified Messaging, you can troubleshoot the issue as follows:

  1. Verify that Exchange users are enabled for Unified Messaging and are assigned to a SIP Uniform Resource Identifier (URI) dial plan that is configured for use with Office Communications Server. For details, see How to Enable a User for Unified Messagingat Microsoft TechNet at http://go.microsoft.com/fwlink/?LinkId=143015 .

  2. Verify that the Exchange administrator has installed a certificate from a certification authority (CA) that is trusted by both the Exchange Server 2007 servers and the Office Communications Server 2007 R2 servers.

  3. Verify that the Exchange administrator has run the ExchUCutil.ps1utility on Exchange to grant Office Communications Server permission to read the Exchange directory attributes in every forest where Exchange Unified Messaging is installed.

See Also

Other Resources

Step 1. Configure Unified Messaging on Microsoft Exchange to Work with Office Communications Server
Step 3. Configure Communications Server to Work with Unified Messaging on Microsoft Exchange Server