The logical process behind a call

In the following figure we have a synthesis of the concepts we have explained about VOICE POLICIES, PSTN USAGE RECORDS, and VOICE ROUTES. The process is to verify if a user is enabled to use a voice feature and to make the call, to define which type of call we are making, and then to route it to the PSTN, the PBX, or the gateway.

We can develop the preceding concept a little more, examining the different mechanisms that Lync uses for outgoing calls.

Note

Every time we perform a reverse-number lookup on the phone number of the caller, (we check it to verify, if it matches one of the phone numbers on the caller's contact list, or in the Global Address List (GAL)). If the number is an internal one, the call will be forwarded to the number of our company that matches the call.

When the user initiates a call, the first evaluation is related to emergency numbers. If the call is an E9-1-1 call, it is immediately delivered to a Location Policy (a Lync Location Policy...