Traffic engineering
182 Avaya Application Solutions IP Telephony Deployment Guide
Additional design criteria
● Each site is to have a suitable number of PSTN trunks (which terminate on PNs in Atlanta
and Boston, and on the G350 Media Gateways in Cleveland).
● This is a general business application (for example, no Call Center agents), where the
average usage per station is assumed to be 0.11 Erlangs, and the average call duration is
assumed to be 200 seconds.
● Each site consists of a single Network Region, and all three Network Regions are
interconnected in the sense of the IRCM matrix.
● One-third of all calls are intercom calls (that is, calls between two stations), one-third are
inbound PSTN trunk calls, and one-third are outbound PSTN trunk calls.
Preliminary calculations
Based on the assumption of 0.11 Erlangs per station, Table 24: Example 1 station usage by
endpoint type on page 182 shows the total station usage for each station category in the
system.
Table 24: Example 1 station usage by endpoint type
Endpoints Atlanta
(Erlangs)
Boston
(Erlangs)
Cleveland
(Erlangs)
DCP Telephones 60 20
IP Telephones 120 50 30
Analog stations 12 2
Road Warriors 3
Analog stations administered
to G350 Media Gateways
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