DETEWE OpenCom 130 Mounting And Commissioning Manual page 84

Network
operator
Example of a PBX network with trunk
groups
In the above example, the following
trunk groups are configured for
PBX 1:
Two S
■
configuration to the network
operator which are assigned to
the "A" trunk group.
Three S
■
configuration to the network
operator which are assigned to
the "B" trunk group.
Two S
■
tions to PBX 2 which are as-
signed to the "C" trunk group.
One S
■
tion to PBX 3 which is assigned
to the "E" trunk group.
Note: A line or a trunk group can-
not be seized directly. It is always per-
formed indirectly via a route.
Routes
A route is a group of trunk groups
enabling a connection in one direc-
tion. If the first trunk group of a
route is fully utilized, the next trunk
group is seized ("trunk group over-
82
PBX Networking
PBX 1 PBX 3
A E
C
B D
PBX 2
Point-to-point
connection
lines in a multi-terminal
0
lines in a system line
0
point-to-point connec-
0
point-to-point connec-
0
flow"). One trunk group can also be
used for different routes.
In the above example, a route set up
Bundle
Trunk line for PBX 1 allows a connection 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:
PBX 1 first searches for a free
■
channel in the "C" trunk group.
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 connec-
tion through, provided it is ap-
propriately configured (refer to
Numbering starting on page 83).
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.
The user does not get a busy sig-
■
nal until the attempt to set up
an indirect connection via the
network operator has also failed.
Note: If an internal connection is
switched via a network operator, the
call is signalled using the external
number of the calling PBX.
For each route you can define a ran-
domly selectable code digit for seiz-
PBX Networking