Mitel SX-200 Documentation page 493

SECTION MITL91 OS/91 1 O-09%180-4UA
Page A-2
DTMF Generator Provisioning
Al.03 Based on the assumptions shown in paragraph 12.09, the prob-
ability of a DTMF generator being available for use is calculated
as under:
Average holding time of DTMF generator per call = 11 X (0.075 + 0.075)
= 1.65 s.
The generator traffic (in Erlangs) is equivalent to the product of the
number of call initiations and the average holding time(s) divided by
3600; i.e.,
Traffic = outgoing traffic X average holding time
average call length
= 140 X 5.55 X 100 X 0.38 X 1.65
180
= 0.075 Erl
Traffic/Generator = 0.038
m a x i m u m d e l a y = 1
H average holding time
From tables for dimensioning of waiting systems for experimental
Holding times, the probability P of being served within 1 s is 0.996.
3600
= 0.61
1.65