Mitel SX-200 Documentation page 487

SECTION 91 OS/91 10-096-l 80-NA
Page 48
12.03 The total traffic can thus be expressed as the sum of:
Terminating Traffic
Originating Traffic - Intercom
Originating Traffic
intercom Originating Traffic
This total is T.
12.04 The ccs/line is dependent on the proportion of Intercom Origi-
nating Traffic XT/2 and the number of lines (N). Table 12-l
shows various intercom traffic levels expressed as percentages of
originating traffic for different values of installed lines. Taking an ex-
ample of 30 percent with 80 installed lines and applying these values
the ccs/line is obtained as follows:
2N
= 4.768 + 3.338 + 2.861
= 10.967
Receiver Provisioning
12.05 The number of receivers required to be installed in the PBX is
dependent on various factors, such as the number of lines and
trunks installed and the amount of traffic flow estimated for the sys-
tem.
12.06 In order to arrive at the quantity required for a particular in-
stallation, the following assumptions are made:
Required grade of service:
l
ABSBH: 98.5 % of all receiver requests are serviced within 3
seconds.
Traffic: 6 ccs/line ABSBH
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50 % originating
Average holding time for a DP receiver = 1.5 s/digit.
l
Average holding time for a DTMF receiver = 0.8 s/digit.
l
All receivers except one are used only for originating calls. One
receiver is allotted for all other uses such as diagnostics.
Call originations are Poisson; holding times are exponential;
queue discipline is random.
All lines originating intercom calls are DP.
l
T / 2
X T / 2
2N 2N
. .