Cisco Cisco IPCC Web Option Design Guide

Unified CVP ports and servers — Refer to the Cisco Unified Customer Voice Portal Solution 
Reference Network Design (SRND), available at:

Gateway ports

Size the following components to support the number of gateway ports needed for your Unified CCE 
system:

Unified CCE servers — See 

Cisco Unified Communications Manager (Unified CM) clusters — Use the Cisco Unified 
Communications Manager Capacity Tool, available only to Cisco employees and partners at:

Unified CVP ports and servers — Refer to the Cisco Unified Customer Voice Portal Solution 
Reference Network Design (SRND), available at:

Gateways — Refer to the Cisco Unified Customer Voice Portal Solution Reference Network 
Design (SRND), available at:

Many traffic models are available for sizing telephony systems and resources. Choosing the right model 
depends on three main factors:

Traffic source characteristics (finite or infinite)

How lost calls are handled (cleared, held, delayed)

Call arrival patterns (random, smooth, peaked)

For purposes of this document, there are mainly two traffic models that are commonly used in sizing call 
center resources, Erlang-B and Erlang-C. There are many other resources on the internet that give 
detailed explanations of the various models (search using traffic engineering).

Erlang calculators are designed to help answer the following questions: 

How many PSTN trunks do I need?

How many agents do I need? 

How many IVR ports do I need? 

Before you can answer these basic questions, you must have the following minimum set of information 
that is used as input to these calculators:

The busy hour call attempts (BHCA)

Average handle time (AHT) for each of the resources

http://www.cisco.com/cgi-bin/CT/PGWCT/ct.cgi  

http://www.cisco.com/cgi-bin/CT/PGWCT/ct.cgi