Sizing the system
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PBX integration
device sizing As described in “PBX integration” on page 3-10, PBX integrations are
accomplished by different methods depending on the PBX type and the
capabilities of the PBX. Although all PBX Integration Devices (PIDs)
perform the same basic functions, they all accomplish it in a slightly
different manner. Therefore, the number of PIDs required to support a
given number of ports varies based on:
nThe number of integrated ports.
nThe type of PID used.
nThe incoming call volume during the busy hour.
Sizing outgoing call
features: Intercom
Paging and OctelNet
Outgoing call features include intercom paging and OctelNet message
delivery. These features require the user of a port by the voice server to
place an outgoing call.
The traffic generated by these features can significantly affect the GOS if
this traffic is not included in the estimate of busy hour offered traffic. If
outcall delivery traffic is managed so tha t the majorit y o f it o ccurs o uts ide
of the busy hour, the impact on busy hour GOS is minimized. For
instance, network delivery schedules can be defined to allow only urgent
messages from priority subscribers to be delivered during th e bu sy per iod.
If a large amount of outcall traffic is e xpected during th e bu sy hour, it may
be preferable to size a separate group of outgoing ports and dedica te th em
to outcalling applications only.
For a conservative estimate of the number of ports required for outgoing
OctelNet messages, use this calculation:
Number of ports = 1 + (average message length * estimated daily
number of messages) / total daily duration of the window during
which OctelNet is free to outcall.
Note: When using this calculation, the following is assumed:
nThe ports are not taken up by other outgoing calls.
nThe schedule is the same for all priority messages.