[This is pre-release documentation and subject to change in future releases. This topic's current status is: Milestone-Ready]

Topic Last Modified: 2010-07-18

Microsoft Communications Server 2010 works with Microsoft Unified Communications Managed API (UCMA) 3.0 Core SDK. If you have external applications built on UCMA 2.0 (which shipped with Office Communications Server 2007 R2), you can run these applications in an environment that includes servers running Communications Server 2010.

If you run a UCMA 2.0 application, homed to an Office Communications Server 2007 R2 pool, you can enable users homed on a Communications Server 2010 pool to call into the application.

To do so, be sure to follow the steps for migrating trusted service entries in “Run Migration Cmdlets” in "Migration from Office Communications Server 2007 R2 to Communications Server 2010." After you follow these steps, the trusted service entries will exist on both the Office Communications Server 2007 R2 pool and the Communications Server 2010 pool, and no further steps are needed for coexistence. Be sure to note that this copies only the trusted service entries and route-related settings.