You can use SIP to interflow BSR calls, but not BSR polling. The polling must be done using either H.323 or ISDN trunks. Once polling determines the best site, the incoming call can be routed to another location by the queue-to-best step. The redirected call can be routed over a SIP trunk.

To use BSR local treatment for calls queued remotely, the queued call must be answered before expiration of the Session Establishment Timer for the SIP trunk signaling group. You must increase the Session Establishment Timer to an appropriate value. For an approach to handling exceeding the timer, see the local treatment Take back example in the Example vector for the local Communication Manager topic.