Procedure 53, Calculating branch office traffic, and lan/wan – Nortel Networks NN43001-314 User Manual
Page 381
Calculations
381
covers only simple
CallPilot voice messaging traffic for a LAN/WAN bandwidth calculation.
The engineering requirement for Multimedia Processing Units (MPU),
such as CallPilot, depends on traffic type (for example, voice, fax, and
speech-recognition) and service type (for example, enterprise networking,
network message service). The MPU requirement calculations, which
require several traffic tables to cover various Grade of Service practices,
do not impact LAN/WAN calculation directly and are not presented here.
Refer to the CallPilot Planning and Engineering Guide (555-7101-101)for
more information.
To leave a voice message for a user in a Branch Office, route the incoming
call to the main office. Similarly, when a user retrieves the voicemail
message, the connection takes place over the LAN/WAN to the main
office. To leave or retrieve a message, the connection requires LAN/WAN
bandwidth.
Procedure 53
Calculating Branch Office traffic, and LAN/WAN
bandwidth without local messaging
(CallPilot) capability
Step
Action
The following are default values of parameters to estimate CallPilot traffic.
Specific traffic information about a site should be used if known.
1
Calculate Messaging traffic:
Average holding time of a voice message: 40 seconds (default
recommended by the CallPilot NTP)
Voice Messaging Traffic (VMT) = Voice Messaging Calls x 40/100
CCS = Voice Messaging Calls x 40/3600 erlangs
If you have no information about messaging calls (leaving or
retrieving a message), use the following approximation:
VMT = 10% x Total MG 1000B traffic in CCS = 10% x
Total MG 1000B CCS traffic/36 (Erlangs)
2
Calculate LAN/WAN bandwidth:
For a G.729A/30 ms codec:
LAN/WAN kbps = VMT (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
.