Consider the following scenario:
- You have a Microsoft Lync Server 2010 environment that contains a Public Switched Telephone Network (PSTN) gateway, and a virtual PSTN gateway that has the same IP address as the PSTN Gateway.
- The virtual PSTN gateway is associated to a Media Termination Point (MTP) resource that has a different IP address from the PSTN gateway signaling IP address. Additionally, the MTP resource is located in a different site.
- You enable media bypass on the trunk connection for all the sites in the Lync Server 2010 environment.
- A PSTN user makes a call that uses MTP in a remote site to a Lync 2010 user.
Note The call is routed to the Lync 2010 user through the virtual PSTN gateway.
This issue occurs because the INVITE request arrives from the same signaling IP address. Therefore Mediation Server cannot determine reliably whether the call comes from the PSTN gateway, or the virtual PSTN gateway.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
Article ID: 2517687 - Last Review: Apr 20, 2011 - Revision: 1