NEC NEAX NDA-24349 - Manual (Page 62)

Chapter 3 System Highlights
Page 3- 10 NEAX2000 IPS Request For Proposal (RFP) Reference Guide
NDA-24349 Issue 4
Traffic Capacity per Line (For TDM Circuits)
Traffic capacity per line (erl/L) can be calculated in accordance with the calculation procedure in
Section 3.4. The traffic capacity per line at various line/truck configurations as the calculation result is
shown in the following table. Though the following table does not cover all NEAX2000 IPS line/trunk
configurations, it covers the typical TDM line/trunk configurations likely to be required in the actual
system. Grade of service is considered as 0.01. Use the Erlang B Table to find the required number of
DTMF register ports for a specific NEAX2000 IPS.
Unit = erl per line
Number of Trunks
Use Erlang B table to determine the number of trunks at a particular grade of service after using the
following formulas:
Incoming: incoming ccs traffic
----------------------- = Erlang B
36 ccs
Outgoing: outgoing ccs traffic
----------------------- = Erlang B
36 ccs
Note : Traffic loads are measured in hundred call seconds, or CCS. Since there are 3,600 seconds in an hour, a
line that's tied up for one hour measures 36 CCS traffic.