Avaya 11-300244 사용자 설명서

Port Sizing

November 2004

Avaya Modular Messaging Concepts and 

Planning Guide

12-21

Planners that have sufficient prior experience in planning and 
implementing messaging systems may prefer to carry out the port sizing 
exercise without referring to the Modular Messaging offers.

This section provides guidelines and calculations that planners can use to 
make estimations such as traffic generated during the busy hour, port 
usage, storage capacity, additional text-to-speech resources, and so on.

Before a planner estimates port requirements, a planner must be familiar 
with the following concepts:

Busy hour is the one-hour period of the day when traffic intensity is the 
highest. 

Suppose that during the busiest day of a business week, a total of 3,500 
calls are received. The hour between 9:00 a.m. and 10:00 a.m experiences 
the heaviest traffic, with 490 incoming calls. This makes 9:00 a.m. to 
10:00 a.m. the busy hour.

Another way of expressing busy hour traffic is as a percentage of total 
daily traffic. In the example above, 490 busy hour calls is 14% of the 
3,500 calls received for the day. 

Most switches can generate traffic reports that provide statistics on a 
weekly, daily, or hourly basis. Usually these reports break up the traffic 
statistics by type of call, for example, incoming calls, outgoing calls, and 
calls to specific hunt groups. These reports can be used to determine what 
the specific traffic patterns are and when the busy hour occurs. If traffic 
statistics are not available, an educated guess at busy hour traffic is 
required. The default planning assumption is 14%.

When calculating the busy hour, planners must realize that the busy hour 
for different divisions or user groups may vary. For example, in an 
organization that has 1,000 employees in the sales division and 2,000 
employees in the technical support division, the busy hour for the sales 
division may be different from that of the technical support division. It is 
important to calculate the busy hour for the entire organization.

Busy hour traffic is normally expressed in minutes, Erlangs, or Centum 
Call Seconds (CCS), using the formula:

Busy hour traffic in Erlangs = [Calls during busy hour x Average duration 
of each call] /3600

For example: