PSTN Usages

The PSTN usage object in Lync Server often seems confusing because it has no settings or configuration options other than a name. There are no user options or policies configured on a usage and it cannot even be created by itself. Instead, PSTN usages can be created only through a voice policy. Usages are also not even associated directly with users. They are associated with routes and voice policies so that they can be considered the glue that ties a route to a voice policy associated with a user.

From a planning perspective it’s best to strive for a 1:1 ratio between PSTN usages and routes. This will allow for the most flexibility in voice policies and the routing configuration later. Naming the PSTN usages and associated routes identically not only simplifies the deployment, but provides future administrators a clear understanding of how the policies have been configured.