An administrator can enable the trunk defined to route calls to “Site 1 Gateway” for Location-Based Routing and associate the “Site 1 Gateway” to site 1. Once enabled, calls that are routed through “Site 1 Gateway“ will only be routed to users that are located in site 1. All calls routed through the “Site 1 Gateway” trunk destined to users in a different site, such as site 2 will be blocked to prevent PSTN toll bypass.

All incoming PSTN calls through “Site 1 Gateway” will only be allowed to route to endpoints located in site 1. For example, when “Lync user 1” travels to site 2, all incoming PSTN calls through “Site 1 Gateway” will not be routed to “Lync user 1” endpoints located in site 2. The same routing rule applies if “Lync user 1” travels to an unknown network site where the user’s location can’t be determined.

The following table outlines the user experience of “Lync user 1” in this context.

Voice routes are referenced in both Voice Policies assigned directly to users, and Voice Routing Policies assigned to network sites. Both policies contain references to routes, which can be used to route a call differently. For example, an administrator can define a Voice Routing Policy for all users located in network site 1 to route all outbound calls through the “Site 1 Gateway” while the Voice Policy of some users define a route for all outbound calls through the “Site 2 Gateway”. While these users are located in network site 1, their outbound calls will be routed through the “Site 1 Gateway”.

When a user is located in a network site configured for Location-Based Routing, the network site’s Voice Routing Policy route overrides the user’s Voice Policy route. This rule is particularly useful for users that temporarily move to a different site. In this particular case a user will always use a gateway that is local to his location; if “Lync user 3” is located at “Site 2”, all his outbound calls will be routed via “Site 2 Gateway”, but if he travels to site 1, all his outbound calls placed while he’s at site 1 will be routed through “Site 1 Gateway”.

The following table illustrates the user experience of Lync user 1 placing an outbound call from the following network sites.

When calls are transferred or forwarded, the routing of calls is affected by Location-Based Routing.

The following table depicts Lync user 1 transferring or forwarding a PSTN call to another Lync user.

The following table illustrates how Location-Based Routing affects how the call is routed based on the location of the Lync user being transferred (Lync user 2, Lync user 4, etc) to a PSTN endpoint

Once location-based routing is configured in the sample topology, the following interactions are enforced.

The following table illustrates whether Location-Based Routing allows simultaneous ringing for different Lync users (i.e. Lync user 2, Lync user 4, etc).

The following table illustrates whether Location-Based Routing allows simultaneous ringing to a PSTN endpoint from different Lync users (i.e. Lync user 2, Lync user 4, etc).