Topic Last Modified: 2011-01-04

In a coexistence scenario, Microsoft Lync Server 2010 communications software clients can interact with clients from earlier versions of Microsoft Office Communications Server. Users homed on different versions of the server and who are using different clients and client versions can interact as follows:

Note:
Users cannot use Lync Server 2010 clients to sign in to previous server versions.

For details about the ability of Lync Server 2010 clients to coexist and interact with clients from earlier versions of Office Communications Server, see Client Interoperability in the Planning documentation.