Automatic routing starts when a user dials a Feature Access Code (FAC) and then the number that the user wants to call. The system analyzes the dialed digits, selects the route for the call, and deletes and inserts digits, if necessary. The system then routes the call over the trunks that you specify in your routing tables. AAR and ARS can access the same trunk groups, and share the same route patterns and other routing information. ARS calls can be converted to AAR calls, and AAR calls can be converted to ARS calls.

The FAC for AAR is usually the digit 8. The FAC for ARS is usually the digit 9 in the US and 0 outside the US. When your Avaya technician or business partner sets up AAR on your server that is running Communication Manager, he or she usually assigns the FAC for AAR. You can administer your own FAC for ARS. With Communication Manager 2.0, you can also use ARS without a FAC.