Cisco Cisco IPCC Web Option Design Guide

grouped into a cluster to provide for scalability and fault tolerance. Unified CM communicates with the 
gateways using standard protocols such as H.323, Media Gateway Control Protocol (MGCP), and 
Session Initiation Protocol (SIP). Unified CM communicates with the IP phones using SIP or Skinny 
Call Control Protocol (SCCP). For details on Unified CM call processing capabilities and clustering 
options, refer to the latest version of the Cisco Unified Communications Solution Reference Network 
Design (SRND) guide, available at:

A single Unified CM subscriber server is capable of supporting hundreds of agents. In a fault-tolerant 
design, a Unified CM cluster is capable of supporting thousands of agents. However, the number of 
agents and the number of busy hour call attempts (BHCA) supported within a cluster varies and must be 
sized according to guidelines defined in the chapter on 

.

Typically, when designing a Unified CCE solution, you first define the deployment scenario, including 
arrival point(s) for voice traffic and the location(s) of the contact center agents. After defining the 
deployment scenario, you can determine the sizing of the individual components within the Unified CCE 
design for such things as how many Unified CM servers are needed within a Unified CM cluster, how 
many voice gateways are needed for each site and for the entire enterprise, how many servers and what 
types of servers are required for the Unified ICM software, how many Unified IP IVR or Unified CVP 
servers are needed, and so forth.

When you select voice gateways for a Unified CCE deployment, it is important to select voice gateways 
that satisfy not only the number of required PSTN trunks but also the busy hour call completion rate on 
those trunks. Busy hour call completion rates per PSTN trunk are typically higher in a contact center 
than in a normal office environment.   For Cisco Catalyst Communications Media Module (CMM) voice 
gateways being used in pure contact center deployments, Cisco recommends provisioning a maximum 
of four T1/E1 interfaces to ensure that the call processing capacity of the voice gateway is satisfactory.

The Unified CVP provides prompting, collecting, queuing, and call control services using standard 
web-based technologies. The Unified CVP architecture is distributed, fault tolerant, and highly scalable. 
With the Unified CVP system, voice is terminated on Cisco IOS gateways that interact with the Unified 
CVP application server (Microsoft Windows Server) using VoiceXML (speech) and H.323 (call control).

The Unified CVP software is tightly integrated with the Cisco Unified ICM software for application 
control. The Unified ICM scripting environment controls the execution of building-block functions such 
as play media, play data, menu, and collect information. The Unified ICM script can also invoke external 
VoiceXML applications to be executed by the Unified CVP VoiceXML Server, an Eclipse and J2EE- 
based scripting and web server environment. VoiceXML Server is well suited for sophisticated and 
high-volume IVR applications, and it can interact with custom or third-party J2EE-based services. These 
applications can return results and control to the Unified ICM script when complete. Advanced load 
balancing across all Unified CVP solution components can be achieved by Cisco Content Services 
Switch (CSS) and Cisco IOS Gatekeepers.

Unified CVP can support multiple grammars for prerecorded announcements in several languages. 
Unified CVP can optionally provide automatic speech recognition and text-to-speech capability. Unified 
CVP can also access customer databases and applications via the Cisco Unified ICM software.