A call originated by the Cisco Unified Communications Manager (Unified CM) first enters the Unified Intelligent Contact Management (ICM) system when someone dials a Unified CM route point that is associated with the JTAPI interface into Unified ICM. These calls initiate a Unified ICM routing script that can be used to place the caller into queue or into a self-service application, select an available agent, or invoke Application Gateway. A call invoked through the JTAPI interface to the Unified ICM is a typical post-route request, This call provides a dialed number, ANI, variables, and returns a label. The Unified CM then delivers the call to the destination specified by the returned label. As with other ACD post-route requests, the exchange ends at the destination. Unified ICM cannot send a subsequent label to that Unified CM unless Unified CM issues another post-route request.
This limitation creates one difference between calls originated by Unified CM and calls originated through a Ingress Voice Gateway. Unified CVP can continue to route and reroute the call as many times as necessary. When calls are originated from Unified CM, routing client responsibilities should be handed off to Unified CVP as soon as possible.
Another difference is when a calls are transferred to a VRU. The ACD routing clients such as Unified CM can be transferred only by using a TranslationRouteToVRU label. When Unified CVP is the routing client, it can handle Translation Route labels as well as the Correlation ID labels that are generated by SendToVRU nodes.
The next sections provide more details on these differences.