When is the IVR leg established in a CCE Call Flow?

In a Cisco CCE call flow, the call has two primary legs—the PSTN/SIP leg (call signaling) and the IVR leg (self-service treatment). These are established as separate connections at different stages of the call flow.

Why the Correct Answer is Right: C is correct. The IVR leg is established when CVP sends an HTTP request to the VVB (or IOS VXML Gateway) to deliver a VXML application for caller interaction. The VVB connects to the caller's audio path, and this HTTP connection constitutes the IVR leg. This is documented precisely in the Cisco CVP Solution Reference Network Design (SRND).

Why Each Incorrect Answer is Wrong: A is wrong because the VXML Server is hosted on CVP—CVP connects to itself internally; this does not define the IVR leg. B is wrong because CVP connects to the Media Server for audio prompts, but this HTTP link is for media retrieval, not IVR leg establishment. D is wrong because the SIP INVITE from the Ingress Gateway to CVP establishes the SIP call leg, not the IVR leg.

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