IP-PBX Vendor

Tested Product

Supported Configuration

Software Versions Tested

OCS 2007 R2

OCS 2007


Cisco Unified Communications Manager

Direct SIP


























Check out the UC Open Interoperability Program for more information.

Known Limitations:

  • The PRACK message sent by CUCM 4.2(3) is malformed by missing the MAXFORWARDS header.  As a result, this configuration requires PRACK to be disabled.  By default, PRACK is disabled in CUCM 4.2(3)
  • For Office Communications Server 2007, this support requires update package for Communications Server 2007 Mediation Server: August 2008 .
  • OCS 2007 may not appropriately normalize the PAI in the 200 OK or UPDATE, resulting in OC displaying a non RFC3966 formatted global number and in failed RNL on OC. When calling from OC 2007 to a Cisco phone number, after the caller gets connected, the name of the person on the Cisco phone may not be shown on Communicator, and instead OC may display the E.164 number (without a "+") for the person on the Cisco phone. This is resolved in OCS 2007 R2
  • When calling from OC 2007 to a Cisco phone number, where the Cisco extension is disconnected or out of service, the Cisco IP-PBX may not notify OC 2007 in a timely manner. This has been remediated in OCS 2007 R2.