374 Appendix B Branch Office engineering example
2Calculate the IP Phone traffic to analog (500/2500-type) telephones:
Number of ATsx CCS for each AT x % of calls to ITs = IT traffic to
analog (500/2500-type) telephones
36 x 5 x 0.6 = 108 CCS (this traffic is part of MC traffic)
3Calculate the IP Phone traffic to main office resources (MOR):
Total ITs x IT CCS - Intra-IT traffic - IT traffic to analog
(500/2500-type) telephones = IT traffic to MOR
120 x 6 - 360 - 108 = 252 CCS
4Calculate the analog (500/2500-type) telephone traffic to Virtual
Trunks(IPPT):
Number of ATsx CCS for each AT x % of calls to Virtual Trunks =
Analog (500/2500-type) traffic to IPPT
36 x 5 x 0.4 = 72 CCS (this traffic is part of MC traffic)
This is the total IPPT traffic.
5Calculate total IP traffic to the LAN:
a. TotalITs x IT CCS + analog traffic to IPPT = Total CCS
120 x 6 + 72 = 792 CCS
b. TotalCCS ÷ 36 = Erlangs
792 ÷ 36 = 22 Erlangs
6Calculate the MC traffic from analog (500/2500-type) telephones to
IP Phones and Virtual Trunks:
IT traffic to analog (500/2500-type) telephones + Analog traffic to
IPPT = MC traffic
108 + 72 = 180 CCS
—End—
Nortel Communication Server 1000
Branch Office Installation and Commissioning
NN43001-314 01.02 Standard
Release 5.0 20 June 2007
Copyright© 2007, Nor tel Networks
.