You can use NCR to reduce the number of trunks for call interflow. This method provides the best approach for balancing loads across a multisite environment and is more cost effective and accurate than pre-delivery routers. You can use the queue-to best vector step to interflow calls between Communication Manager over the SIP service provider network. You can use SIP to interflow BSR calls, but not BSR polling. You can use BSR polling through other methods such as Polling Over IP without B-Channel.

The queue-to best vector step activates NCR when the BSR feature determines that a particular BSR location is the best location and that location is administered with the Net Redir field set to y on the BSR Application Table screen. Note that the administered Interflow VDN field on the Best Service Routing Application screen must be a SIP service provider or VPN endpoint number without a trunk/ARS/AAR access codes included. For some SIP service provider switch dialing plans, you must prefix the long-distance access code, for example, 1 in the United States, to the SIP service provider number for the call to be successfully routed by the SIP service provider switch.

As shown in the following example, the Best Service Routing Application Plan screen must include locations that have the Net Redir field set to y.

An appropriate vector is then used to identify a BSR best location and NCR is activated by the queue-to-best vector step.