This document describes the flow of an incoming call to CVP which is routed to an Agent when the Agent Greeting feature is enabled. The call messages are tracked in CVP, CUCM ccm and CUCM cti logs.
Contributed by Kristof Van Coillie, Cisco TAC Engineer.
Cisco recommends that you have knowledge of these topics:
Voice Extensible Markup Language (VXML)
Session Internet Protocol (SIP)
The information in this document is not based on any software or hardware versions.
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Step 1. CVP receives the incoming invite from the ingress Gateway.
Step 3. The ICM script is configured with a Send to VRU node and returns an ICM_TEMPORARY_CONNECT message to CVP. This informs CVP to establish a connection with the bootstrap script on the VXML gateway.
Step 9. This is no different than normal call flow, CVP establishes a connection with the ringback script (to provide ringback to the caller) and sends a SIP INVITE to CUCM with the agent label which is shown in the CUCM ccm logs.
01027218.005 |09:52:57.254 |AppInfo |SIPTcp - wait_SdlReadRsp: Incoming SIP TCP message from 10.48.54.196 on port 25138 index 11 with 1182 bytes:
INVITE sip:firstname.lastname@example.org;transport=tcp SIP/2.0
Via: SIP/2.0/TCP 10.48.54.196:5060;branch=z9hG4bKipFCSahbAXU9YZu9ysNQOQ~~240
From: 6611112 <sip:email@example.com:5060>;tag=ds9afb32e2
Step 10. CUCM routes the call to the agent. The agent answers using the Agent Desktop.
Step 11. Media is established between the Ingress Gateway and the agent phone now (in CVP the ringback leg is being disconnected). CTI Manager informs the application Peripheral Gateway (PG) that the call is connected.
Step 12. Next the application requests CUCM to allocate the build-in-bridge (BiB) on the phone and provide the number to dial, this is the bootstrap label with the Correlation Identification (ID) added to it.