Core Issue
The user receives a fast busy signal when calling from an IP phone registered to one Cisco CallManager to a Computer Telephony Integration (CTI) port registered to another Cisco CallManager within the same cluster. Both the IP phone and the CTI port are configured for Alternate Automatic Routing (AAR).
The user, however, is able to call other AAR-enabled IP phones from this IP phone.
This is working as designed.
Resolution
This is working as designed. There is no AAR support for any call that originates from or terminates to Cisco CTI Route Point.
These scenarios are supported by AAR:
- A call originates from a line or Dialed Number (DN) of a IP phone within one location and terminates to a line or DN of another IP phone within another location. This includes a call terminated at the shared line with terminating IP phone devices residing in multiple locations, and Cisco voice mail port.
- An incoming call through a gateway device within one location and terminating to a line or DN of another IP phone within another location. This includes a call terminated at the shared line with terminating IP phone devices residing in multiple locations, and Cisco voice mail port.
These scenarios are not supported by AAR:
- Any call that originates from any device within one location and terminates to non-IP phone device, and a non-Cisco voice mail port within another location.
- Any call that originates from Cisco CTI Route Point.
- At initial release, this feature does not fully support any call where the originating or terminating IP phone is used by the Extension Mobility feature user. It is also unsupported if the originating IP phone is in a separate location from the user's normal IP phone. The AAR group is on the line and the AAR Calling Search Space (CSS) is on the device. The call uses the phone CSS to route out a local gateway, but the prefixed digits are according to the lines of the AAR group.
- At initial release, this feature does not support any call terminating to a voice mail system connected to the Cisco CallManager through a gateway (using route pattern to terminate to the voice mail system).
For more information on AAR, refer to these documents:
