Cisco Cisco Unified Customer Voice Portal 10.5(1)
Figure 1: SIP-Based Unified CVP Solution
SIP-Based Call Flow
Calls arrive from a PSTN via a TDM connection into an Ingress Gateway. The Ingress Gateway
sends a new call message to the SIP Proxy Server, which forwards it to the SIP Service. The
SIP Proxy Server, in addition to forwarding SIP messages to appropriate devices, also provides
failover and redundancy support for those devices. The SIP Service consults Unified ICME
(actually, in this particular case, Unified CCE) via the ICM Service (this and all subsequent
interactions between any Unified CVP component and Unified ICME pass through the ICM
Service). This consultation causes Unified ICME to run a routing script. The routing script
requires the call to be transferred to a VRU, so Unified ICME instructs the SIP Service to extend
a second call leg (that is, deliver the call) to a VXML Gateway (which is often identical with
the Ingress Gateway). The VXML Gateway sends a message to the IVR Service, which then
requests scripted instructions from Unified ICME. Unified ICME exchanges VRU instructions
with the VXML Gateway via the IVR Service. Among these VRU instructions can be requests
to the VXML Gateway to invoke more sophisticated applications on the VoiceXML Server.
Such requests will result in multiple exchanges between the VoiceXML Server and the VXML
Gateway, ultimately ending in a reply to Unified ICME via the IVR Service. VoiceXML Server
applications are designed and built using VoiceXML Studio (not shown in the diagram, since
it is essentially an offline tool).
sends a new call message to the SIP Proxy Server, which forwards it to the SIP Service. The
SIP Proxy Server, in addition to forwarding SIP messages to appropriate devices, also provides
failover and redundancy support for those devices. The SIP Service consults Unified ICME
(actually, in this particular case, Unified CCE) via the ICM Service (this and all subsequent
interactions between any Unified CVP component and Unified ICME pass through the ICM
Service). This consultation causes Unified ICME to run a routing script. The routing script
requires the call to be transferred to a VRU, so Unified ICME instructs the SIP Service to extend
a second call leg (that is, deliver the call) to a VXML Gateway (which is often identical with
the Ingress Gateway). The VXML Gateway sends a message to the IVR Service, which then
requests scripted instructions from Unified ICME. Unified ICME exchanges VRU instructions
with the VXML Gateway via the IVR Service. Among these VRU instructions can be requests
to the VXML Gateway to invoke more sophisticated applications on the VoiceXML Server.
Such requests will result in multiple exchanges between the VoiceXML Server and the VXML
Gateway, ultimately ending in a reply to Unified ICME via the IVR Service. VoiceXML Server
applications are designed and built using VoiceXML Studio (not shown in the diagram, since
it is essentially an offline tool).
Once the self service portion of the call is completed, the Unified ICME routing script places
the caller into queue. This call is already at a VRU, and it waits there for the agent to become
available. Meanwhile, further VRU instructions are exchanged between Unified ICME and the
VXML Gateway via the IVR Service to play messages and recorded music. When the agent
becomes available, Unified ICME sends a message to the SIP Service, which forwards a message
via the SIP Proxy Server to the Ingress Gateway and to Unified CallManager to transfer the
call away from the VXML Gateway and deliver it to the Unified CallManager phone.
the caller into queue. This call is already at a VRU, and it waits there for the agent to become
available. Meanwhile, further VRU instructions are exchanged between Unified ICME and the
VXML Gateway via the IVR Service to play messages and recorded music. When the agent
becomes available, Unified ICME sends a message to the SIP Service, which forwards a message
via the SIP Proxy Server to the Ingress Gateway and to Unified CallManager to transfer the
call away from the VXML Gateway and deliver it to the Unified CallManager phone.
During the VRU exchanges, the VXML Gateway interacts with an ASR/TTS Server to have
text played as speech or speech recognized as data, and with a Media Server (not shown in the
diagram, but connected to the VXML Gateway) to fetch audio files and prompts. These two
devices, as well as the VoiceXML Server, can be located behind a Content Services Switch
(CSS), which offers them sophisticated failover and redundancy capability. (CSSs are optional,
though recommended, and are not displayed in the diagram.)
text played as speech or speech recognized as data, and with a Media Server (not shown in the
diagram, but connected to the VXML Gateway) to fetch audio files and prompts. These two
devices, as well as the VoiceXML Server, can be located behind a Content Services Switch
(CSS), which offers them sophisticated failover and redundancy capability. (CSSs are optional,
though recommended, and are not displayed in the diagram.)
Planning Guide for Cisco Unified Customer Voice Portal 4.0(1)
15
Chapter 1: Product Overview
Unified CVP Solution Components