Cisco Cisco IP Contact Center Release 4.6.1 Leaflet

Central to designing a Cisco Unified Contact Center (or any call center) is the proper sizing of its 
resources. This chapter discusses the tools and methodologies needed to determine the required number 
of call center agents (based on customer requirements such as call volume and service level desired), the 
number of Unified IP IVR ports required for various call scenarios (such as call treatment, prompt and 
collect, queuing, and self-service applications), and the number of voice gateway ports required to carry 
the traffic volume coming from the PSTN or other TDM source such as PBXs and TDM IVRs.

The methodologies and tools presented in this chapter are based on traffic engineering principles using 
the Erlang-B and Erlang-C models applied to the various resources in a Unified CCE deployment. 
Examples are provided to illustrate how resources can be impacted under various call scenarios such as 
call treatment (prompt and collect) in the Unified IP IVR and agent wrap-up time. These tools and 
methodologies are intended as building blocks for sizing call center resources and for any telephony 
applications in general.

 lists the topics that are new in this chapter or that have changed significantly from previous 

releases of this document.

It is important to be familiar with, and to be consistent in the use of, common call center terminology. 
Improper use of these terms in the tools used to size call center resources can lead to inaccurate sizing 
results.

The terms listed in this section are the most common terms used in the industry for sizing call center 
resources. There are also other resources available on the internet for defining call center terms.

This chapter contains no major updates for this release.