Symptoms
A media time-out occurs on the Microsoft Office Communications Server 2007 R2, Mediation Server if no Real-Time Transport Protocol (RTP) packets or Real-Time Control Protocol (RTCP) packets are received for 30 seconds. When Office Communications Server 2007 R2, Mediation Server interacts directly with Cisco Call Manager (CCM) through Session Initiation Protocol (SIP), the following scenarios occur.
Note In these scenarios, no RTP packets or RTCP packets are received for a call.
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For a call that is on hold, the direction attribute is inactive from the perspective of both the Mediation Server and CCM. In this case, CCM does not send any RTP packets or RTCP packets. Existing Mediation Server code ignored the media time-out. Therefore, the call is not dropped.
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A CCM user joins in an Office Communications Server 2007 R2 conference and then mutes the telephone. Additionally, the direction attribute for the Mediation Server for the interaction with CCM is sendonly. Also, the direction attribute for the telephone is recvonly. In this case, CCM does not send any RTP packets or RTCP packets when the telephone is muted. Therefore, the call is dropped after 30 seconds.
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An Office Communicator user calls a CCM user who is configured to use Cisco Unity voice mail. When the call is connected to Cisco Unity, the call obtains the original media packets from Cisco Unity. The Office Communicator user is then prompted to leave a voice mail message. However, Cisco Unity does not send any RTP packets or RTCP packets when the Office Communicator user leaves a message. Therefore, a media time-out occurs after 30 seconds and the call is disconnected. After this occurs, the Office Communicator user cannot leave voice mail.
Resolution
To resolve this problem, install the following update:
977937 Description of the cumulative update for Office Communications Server 2007 R2, Mediation Server: April 2010
After you apply this update, the Mediation Server is configured to ignore media time-outs when the server interacts with gateway peers that do not support RTCP.
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
More Information
To make sure that the Mediation Server operates as expected together with gateway peers that do not support RTCP, this fix adds a new configuration file setting to the Mediation Server. This configuration file setting is called GatewayIgnoreMediaTimeout. This setting contains one of two values: True or False. The configuration file is the MediationServerSvc.exe.config file. You should put this file into the directory in which the Mediation Server is installed. To find this directory, search for the Microsoft.RTC.MediationServerCore.dll file.
Note By default, the Mediation Server is installed in the following location on drive C:
C:\Program Files\Microsoft Office Communications Server 2007\Mediation ServerIf this file is set to ignore media time-outs for the gateway side of the Mediation Server, its contents are displayed as follows.
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="GatewayIgnoreMediaTimeout" value="True" />
</appSettings>
</configuration>
If the file does not exist, the default value for GatewayIgnoreMediaTimeout is set to False. If the Mediation Server is set to ignore media time-outs for its gateway side, it will automatically enable session timers for its interactions with its gateway side peer. If the session timers expire, the call is automatically cleared. If the Mediation Server has to ignore media timeouts for its gateway-side interactions, but the session timers do not have to be enabled, a configuration file setting is used. This configuration file setting is called GatewaySessionTimer. This setting contains one of two values: True or False. A False value disables session timers for gateway side interactions.
