alternate network (for example, the PSTN). AAR uses the dialed digits to establish the on-cluster
destination of the call and then combines them with the called party's External Phone Number Mask. The
combination of these two elements must yield a fully qualified number that is routable by the alternate
network.
phone B located in New York. If locations-based call admission control denies the call, AAR retrieves
the External Phone Number Mask of the New York phone (212-555-XXXX) and uses it to derive the
fully qualified number (212-555-1234) that is routable on the PSTN.
number. Cisco recommends that you do not include this prefix as part of the External Phone Number
Mask of phones because it would be displayed as part of the Calling Party Identification (CallerID) for
any calls made by the phones to an off-net destination. Instead, Cisco recommends that you add the "1"
as part of the AAR group configuration.
properly by the origination branch's dial plan. Furthermore, if the point of origin is located in a different
Numbering Plan Area (NPA, or area code), a prefix of "1" might be required as part of the dialed string.
configure prefix digits to add to the DNs for calls between the two groups, including prefix digits for
calls originating and terminating within the same AAR group.
America)
characteristics. We could place the DNs for San Francisco and New York into a single AAR group and
configure the group such that AAR calls placed within this same AAR group are prefixed with 91. For
phone A in San Francisco to reach phone B in New York (at 212-555-1212), the AAR group
configuration prefixes 91 to the dialed string, yielding a completed string of 91-212-555-1212.
to the completed dial string be sent through the origination site's dial plan. To ensure that this is the case,
select the appropriate AAR calling search space on the device configuration page in Cisco CallManager