Nortel Networks NN43001-563 User Manual
Page 98
98
ITG engineering guidelines
CCS/user = 4*150/100 = 6 CCS
Tv = 120*6 = 720 CCS
2
Calculate fax on IP traffic during busy hour.
CCS/fax sent = 3*48/100 = 1.44 CCS
CCS/fax received = 5*48/100 = 2.4 CCS
Total fax CCS (Tx + Rx) = 1.44*25 + 2.4*20 = 36+ 48= 84 CCS
3
Calculate IP Trunk 3.01 (and later) traffic during busy hour.
Total traffic (T) = Tv + Tx = 720 + 84 = 804 CCS
4
Refer to the Poisson P.01 table (
Table 10 "Trunk traffic – Poisson 1%
blocking Grade of Service" (page 99)
) to find the number of IP Trunk
3.01 (and later) ports required for 1% blocking Grade of Service.
For P.10 blocking Grade of Service, refer to
Poisson 10% blocking Grade of Service" (page 100)
.
804 CCS can be served by 35 IP Trunk 3.01 (and later) ports
with P.01 blocking Grade of Service. Two ITG-Pentium 24-port
trunk cards are needed to serve this customer.
5
Calculate average bandwidth use on the TLAN subnet.
For voice:
720/36*30.7 = 614 kbit/s
For fax:
84/36*46.1 =108 kbit/s
Total bandwidth = 614 + 108 = 722 kbit/s
6
Adjust requirement for traffic peaking
Peak hour bandwidth requirement = 722*1.3 = 939 kbit/s
This is the spare bandwidth a TLAN subnet requires to transmit
the VoIP and fax traffic. Nortel recommends that the TLAN
subnet handle IP Trunk 3.01 (and later) traffic exclusively.
—End—
This example is based on the G.729AB codec with 30 ms payload size and
Silence Suppression enabled. For relations of user-selectable parameters
such as payload size, codec type, packet size and QoS, refer to
Nortel Communication Server 1000
IP Trunk Fundamentals
NN43001-563
01.01
Standard
Release 5.0
30 May 2007
Copyright © 2007, Nortel Networks
.