BELGACOM Forum 500 Specifications download pdf (Page 84)

PBX Networking82

PBX Networking

Example of a PBX network with trunk groups

In the above example, the following trunk groups are configured

for PBX 1:

z Two S

lines in a multi-terminal configuration to the network

operator which are assigned to the “A” trunk group.

z Two S

point-to-point connections to PBX 2 which are assigned

to the “C” trunk group.

z One S

point-to-point connection to PBX 3 which is assigned to

the “E” trunk group.

Note: A line or a trunk group cannot be seized directly. It is

always performed indirectly via a route.

Routes

A route is a group of trunk groups enabling a connection in one

direction. If the first trunk group of a route is fully utilized, the

next trunk group is seized (“trunk group overflow”). One trunk

group can also be used for different routes.

In the above example, a route set up for PBX 1 allows a connec-

tion to PBX 2. Trunk groups “C,” “E” and “A” are assigned to this

route. If a user connected to PBX 1 wants to reach a party in

PBX 2, lines will be seized in the following order:

z PBX 1 first searches for a free channel in the “C” trunk group.

z If all the lines in trunk group “C” are busy, the system tries to

set up a connection via trunk group “E”. PBX 3 switches the

connection through, provided it is appropriately configured

(refer to Numbering starting on page 83).

z If it was not possible to set up an indirect connection via PBX 3,

the system tries again via trunk group “A”. The “prefix” neces-

sary for this can be configured with the route.

Bundle

PBX 1

PBX 2

PBX 3

Network

operator

Trunk line

Point-to-point

connection

1 2 ... 79 80 81 82 83 84 85 86 87 88 89 ... 143 144

No comments

BELGACOM Forum 500 Specifications Page 84