Topic Last Modified: 2010-12-13

Enterprise Voice and dial-in conferencing require public switched telephone network (PSTN) connectivity components, which must include at least one Mediation Server. When deploying Enterprise Voice, the Mediation Server requires at least one peer, which can be a PSTN gateway, IP-PBX, or Session Border Controller (SBC) for an Internet Telephony Service Provider to which you connect by configuring a Session Initiation Protocol (SIP) trunk. Dial-in conferencing requires either the deployment of Enterprise Voice or the deployment of a Mediation Server and a PSTN gateway. You must associate the PSTN gateway with the Mediation Server. You can associate one or more previously deployed PSTN gateways with the Mediation Server, if the gateway is not already associated with another Mediation Server, or you can add one or more new PSTN gateways that you plan to set up and want to associate with the Mediation Server.

Note:
If you want to use a PSTN gateway, you can set it up later, but full functionality will be limited until the PSTN gateway is defined and configured.

A green check mark next to a gateway indicates that it is the default gateway. This is the peer to which you want the Mediation Server to route calls from Microsoft Office Communications Server 2007 R2 Enterprise Edition or Standard Edition servers to the PSTN. The first gateway that you specify is automatically designated as the default gateway, but you can make any gateway in the list the default by clicking it and then clicking Make Default.

For details about PSTN gateway features and support, see PSTN Gateway Deployment Options in the Planning documentation. For details about PSTN gateways and other connectivity components, see PSTN Connectivity Components in the Planning documentation. For details about the required PSTN connectivity components, see Components Used for Dial-In Conferencing in the Planning documentation and Dial-in Conferencing Configuration Prerequisites and Permissions in the Deployment documentation. For details about designing the topology for an Enterprise Edition Front End pool, see Define and Configure a Front End Pool in the Deployment documentation. For details about designing the topology for a Standard Edition server, see Define and Configure a Front End Pool in the Deployment documentation. For additional details about designing a Mediation Server topology and specifying gateway information, see Define Mediation Servers for a Site in the Deployment documentation.