Topic Last Modified: 2011-02-25

Follow the steps in this topic to use Topology Builder to define a peer with which you can associate a Mediation Server in order to provide connectivity to the PSTN for users enabled for Enterprise Voice. A peer to the Mediation Server can be a PSTN gateway, an IP-PBX, or a Session Border Controller (SBC) for an Internet Telephony Service Provider (ITSP) to which you connect by configuring a SIP trunk.

It is not necessary to define a Mediation Server before you define its peer, but the procedures in this section describe how to define a stand-alone Mediation Server pool when there is at least one peer in the topology.

This topic assumes that you have set up at least one internal Front End pool or Standard Edition server in at least one central site as described in Define and Configure a Front End Pool and Publish the Topology in the Deploying Lync Server 2010 section of the Deployment documentation. This topic also assumes that you have verified that your infrastructure meets the prerequisites described in Software Prerequisites for Enterprise Voice and Security and Configuration Prerequisites for Enterprise Voice.

To define a peer for the Mediation Server

  1. Start Topology Builder: Click Start, click All Programs, click Microsoft Lync Server 2010, and then click Lync Server Topology Builder.

  2. Right-click the PSTN Gateways node, and then click New PSTN Gateway.

  3. In the Define New IP/PSTN Gateway dialog box, type the FQDN or IP address of the peer.

    If you specify TLS as the transport type, you must specify the FQDN instead of the IP address of the peer of the Mediation Server.
  4. Under Listening Port for IP/PSTN Gateway, type the listening port that the gateway, PBX, or SBC will use for SIP messages from the Mediation Server. (By default, the ports are 5066 for TCP and 5067 for TLS on a PSTN gateway, PBX or SBC. On a Survivable Branch Appliance at a branch site, the default ports are 5081 for TCP and 5082 for TLS.)

  5. Under SIP Transport Protocol, click the transport type that the peer uses, and then click OK.

    For security reasons, we strongly recommend that you deploy a peer to the Mediation Server that can use TLS.
Before you proceed to the next step, ensure that the peer that you defined is running and using the FQDN or IP address that you specified.

Next, to add the peer to the topology, follow the procedures in Publish the Topology in the Finalizing and Implementing the Topology Design section of the Deployment documentation. You must publish your topology each time you use Topology Builder to build or modify your topology so that the data can be used to install the files for servers that are running Lync Server.