PBX Networking Configuration
9.3.3 Numbering
A user can seize a particular route by pre-dialling a specific code digit. With this
“open numbering”, a user must always dial this code digit and then the telephone number in order to reach a party in another PBX.
If none of the telephone numbers in your PBX network occur twice, you can also configure “closed numbering”, allowing the same telephone number to be used for reaching each user within the PBX network.
With closed numbering, the OpenCom 107 determines which route to seize from the telephone number dialled. The information needed for routing a call can be configured in a numbering table containing up to 100 entries. You use this table to assign telephone numbers and/or ranges of telephone numbers to a particular route.
A default entry in the numbering table makes it possible to seize a “default route” for all remaining unassigned numbers. In particular, this simplifies configuration of the OpenCom 107 as a subsidiary system: the only entry you assign to the default entry is the route to the host system
PBX
100-199 c d a b
PBX
400-499
4: b
D: c
D: a
PBX
200-299 e g h
3: e
5: h
D: d f
PBX
300-399 k
5: k
D: f
PBX
500-599 i
3: i
D: g
D:Default
Route
Example of closed numbering tables
The automatic switching of call requests (i.e. routing) by means of trunk group overflow or default numbering can lead to “circular switching”.
To avoid this, a “transit” counter is incremented whenever a connection is switched through on Q.SIG lines. When the configured maximum value is reached, further switching stops.
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