Cisco Cisco Unified Contact Center Enterprise 9.0(2) Design Guide

Grade of Service, or the percentage of calls that are blocked because not enough ports are available

Ports (lines), or the number of Unified IP IVR or gateway ports 

Cisco is continually enhancing the Cisco Unified Communications Resource Calculators, which 
currently include the following calculators:

Standard Unified CCE Resource Calculator — Designed to provide outputs for a single call center 
with a single trunk group. It allows the user to vary the number of agents.

Advanced Unified CCE Resource Calculator — Includes all the calculations of the Standard 
calculator and adds the ability to allocate traffic between multiple trunk groups to include calls 
going to a self-service IVR. It also has inputs for confidence and growth factors.

Unified IP IVR Self-Service Calculator — A standard Erlang B calculator for determining the 
number of ports required on a self-service IVR. It has inputs for up to five port groups or separate 
IVRs.

The latest versions of these calculators and their associated user guides are available at 

The Cisco Unified CCE Resource Calculators are accessible to Cisco internal employees and Cisco 
partners. These tools are based on industry Erlang traffic models. Other Erlang traffic calculators 
available on the Web can also be used for sizing various contact center resources.

 is a snapshot of the current Standard Unified CCE Resource Calculator, followed by a 

definition of each of the input and output fields, how to use them, and how to interpret them.