Article ID: 971844
When a Private Branch Exchange (PBX) telephone user calls a Microsoft Office Communications Server (OCS) 2007 R2 user, the calling party name that exists in PBX is stripped at the OCS 2007 R2 Mediation Server stage. Because the PBX telephone user does not exist in Active Directory directory service, no name appears in Microsoft Office Communicator 2007 R2.
This problem occurs because OCS 2007 R2 Mediation Server does not forward the display name information from the Unified Communications (UC) side to the gateway side. Therefore, the Communicator 2007 R2 client does not receive the display name information.
To resolve this issue, apply the following updates: