Symptoms
Assume that you have a client in a Microsoft Lync Server 2010 environment. The client accepts a call by using a third-party voice mail device or forwards a call to a third-party voice mail device. In this situation, you receive the following error message from Lync Server 2010 Mediation Server:
488 Not Acceptable Here
Note This error message indicates that media negotiation on the gateway side of third-party voice mail system failed because a Session Description Protocol (SDP) response contained a bandwidth field that the SDP did not expect.
Cause
This issue occurs because the SDP cannot handle multiple bandwidth values.
Resolution
To resolve this issue, install the following cumulative update:
2847888 Description of the cumulative update for Lync Server 2010, Unified Communications Managed API 3.0 Runtime: July 2013