Assume that you deploy a Mobility server in a Microsoft Lync Server 2010 environment. In this situation, a user who is homed on a server pool that has Mobility service installed cannot join the meeting by using a mobile device.
This issue occurs because the meeting request is forwarded to the server pool that the meeting organizer is homed on. However, the server pool does not have the Mobility service installed.
To resolve this issue, install the following cumulative update:
2514979 Description of the cumulative update package for Lync Server 2010, Web Components Server: November 2011
Note After you apply the update, the join request is only forwarded to the server pool that has the ports for the Mobility service. The ports for the Mobility service are defined in the Topology Builder file. If the server pool does not have a port for the Mobility service, the director handles the join request.