Within the VX, the call routing table processes and directs calls to the desired destination. Using the Called Number, VX evaluates each Call Route within a Call Route Table to determine all possible matching routes. The call route specifies an input number to match against, as well the corresponding output number. The output number need not necessarily be the same as the input number. The output number is used to place the outgoing call.
Standard VX Call Routing
The figure above shows a call from the PSTN to 555-1213 which is processed by VX Call Routing Table #2. The Called Number, 5551213, is evaluated against the call routing table. In this case, the Input Item #8 uniquely matches the called number. The call is sent to the OCS Trunk Group using the corresponding output number (5551213). In this case the original called number remains unchanged.
Active Directory as a Database
Active Directory provides a repository of data about network users. Some of these numbers would likely be placed into the VX call routing table in order for calls to be completed to those devices.
Rather than populate VX's Call Routing table with numerous discrete entries, there would be a significant advantage in utilizing the data within AD to make call routing decisions.
Below are examples of phones numbers that may be stored in a user's AD entry.
The following sections detail examples of VX's AD Integrated Call Routing functions.