Nortel Networks NN43001-314 - Manual (Page 379)

Calculations 379
= 333 kbps
Refer to Table 44 "LAN/WAN bandwidth for one channel (one
Erlang)" (page 377) for other codecs or payload sizes.
—End—
Branch Office conference engineering
With no local conference
Two parties at a Branch Office using IP Phones call each other. They
conference-in a third party from the same Branch Office. The conference
calls use a LAN/WAN to reach the Conference Bridge at the main office.
Refer to
Table 44 "LAN/WAN bandwidth for one channel (one Erlang)" (page
377) for bandwidth requirements if the codec or payload or both differ from
what is assumed in the following Branch Office conference scenarios.
The calculated conference LAN/WAN bandwidth is added to the normal
LAN/WAN requirement between the Branch Office and the main office for
ITG trunks or Virtual Trunks.
Procedure 51
Calculating unspecified conference traffic
Step Action
When you lack specific information about conference traffic, use the
following standard ratio of conference traffic to general traffic. In Nortel PBX
engineering, a network group of 32 loops is comprised of 28 traffic loops, 2
Conference loops, and 2 TDS loops. Using the ratio of 2:28, the conference
traffic is about 7% (rounded up from 6.7%) of total traffic. Use the default
value of 7% in place of specific information about conference traffic.
1 Calculate conference traffic:
Branch Office total traffic (TCCS) = # of IP Phones x CCS for each
telephone
Conference traffic (TCON) = TCCS x 0.07 CCS = TCCS x 0.07/36
Erlangs
2 Calculate LAN/WAN bandwidth:
For a G.729A/30 ms codec:
LAN/WAN kbps = TCON (erlangs) x 9 kbps
For a G.711/30 ms codec:
Nortel Communication Server 1000
Branch Office Installation and Commissioning
NN43001-314 01.02 Standard
Release 5.0 20 June 2007
Copyright © 2007, Nortel Networks
.