This article describes an update to the-10 second timer in the Lync Server 2010 Outbound Routing (OBR) component. After you apply this update, the timer no longer applies to non-E911 Public Switched Telephone Network (PSTN) calls.
The 10-second timer was added to Lync Server 2010 OBR components by the update that is described in Knowledge Base (KB) article 2565378. After update 2565378 is applied, the OBR component routes calls to other PSTN gateways if a PSTN gateway does not send a provisional or final response within 10 seconds. For example, the OBR component reroutes the call if the PSTN gateway does not send a 183 session progress message. However, in certain network environments, the gateway takes longer than 10 seconds to send a response. Therefore, calls are canceled before they can be completed.
To resolve this issue, install the following cumulative update:
2701585 Description of the cumulative update for Lync Server 2010: June 2012
For more information about update 2565378, click the following article number to view the article in the Microsoft Knowledge Base:
2565378 An update is available that improves the efficiency of PSTN call routing in Lync Server 2010