Design inputs
Issue 3.4.1 June 2005
145
The most commonly used default value for a general business system is 0.11 Erlangs per
station. The most common way to determine trunk usage rates is to divide the total traffic load
that is carried by each trunk group by the number of trunks in the group. It is difficult to assign a
typical default value for usage per trunk. Such usage can vary greatly from system to system,
and even from trunk group to trunk group within a particular system.
Traffic usage has two components:
●
Average call duration (also known as call hold time)
●
Average number of calls per hour
Systems are usually engineered to accommodate the busiest hour of a normal business day.
The number of calls that are completed during that busiest hour is denoted by Busy Hour Calls
Completed (BHCC). BHCC is not be confused with Busy Hour Calls Attempted (BHCA), which
represents the total number of calls attempted during the busiest hour, regardless of how many
of those calls are actually successfully completed. The general expression for the relationship
between BHCC, average call duration, and usage is:
A commonly used default value for average call duration in a general business system is 200
seconds per call.
Example 1
shows how to calculate the station usages using the data given.
Example 1
Assume that the customer has sites in Atlanta, Boston, and Cleveland that the customer wants
to populate with the following endpoints (
Table 19: Example 1 configuration data
).
Usage (Erlangs)
BHCC
seconds per call
×
3600
-------------------------------------------------------------
=
Table 19: Example 1 configuration data
Endpoints
Atlanta
Boston
Cleveland
DCP
Telephones
540
180
IP Telephones
1,080
450
270
Analog
stations
108
18
Road Warriors
27
Other
Two G350 Media Gateways, each of
which supports 18 analog stations,
and a suitable number of
circuit-switched PSTN trunks
Summary of Contents for Application Solutions
Page 1: ...Avaya Application Solutions IP Telephony Deployment Guide 555 245 600 Issue 3 4 1 June 2005 ...
Page 20: ...About This Book 20 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 21: ...Issue 3 4 1 June 2005 21 Section 1 Avaya Application Solutions product guide ...
Page 22: ...22 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 106: ...Call processing 106 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 124: ...Avaya LAN switching products 124 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 139: ...Issue 3 4 1 June 2005 139 Section 2 Deploying IP Telephony ...
Page 140: ...140 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 186: ...Traffic engineering 186 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 204: ...Security 204 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 228: ...Avaya Integrated Management 228 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 274: ...Reliability and Recovery 274 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 275: ...Issue 3 4 1 June 2005 275 Section 3 Getting the IP network ready for telephony ...
Page 276: ...276 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 356: ...Network recovery 356 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 366: ...Network assessment offer 366 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 367: ...Issue 3 4 1 June 2005 367 Appendixes ...
Page 368: ...Appendixes 368 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 394: ...Access list 394 Avaya Application Solutions IP Telephony Deployment Guide ...
Page 414: ...DHCP TFTP 414 Avaya Application Solutions IP Telephony Deployment Guide ...