Using Voip Telephony To Extend The Downstream Isdn Pbx - Lancom 1722 VoIP User Manual

With the altered number, the Call Manager begins to search the call routing
table from top to bottom. If the Call Router cannot find a matching entry
there, the call is forwarded directly to the internal number:
Remote site Call Router
dials receives
0 123 456 789 456 789
0 123 555 555 1 555 555 1
0 123 555 555 2 555 555 2
5.2.2

Using VoIP telephony to extend the downstream ISDN PBX

This example shows how to configure a LANCOM when a downstream ISDN
PBX is enhanced with VoIP telephony capability. Until now, the MSNs '11' to
'13' for the ISDN connection have been used for two ISDN telephones and one
analog fax. The LANCOM will now be switched between the public ISDN con-
nection and the ISDN PBX.
The PBX is configured to allow subscribers to receive immediate

access to an outside line when they pick up the receiver.
This ISDN PBX is operated as a downstream PBX on the ISDN NT interface of
the LANCOM.
LANCOM 1722 VoIP – LANCOM 1724 VoIP
Assigned via number in
use
internal destination 11
number for SIP line
ISDN mapping 11
ISDN mapping 12
Chapter 5: Configuring Voice over IP
correct call
route
none
none
none
Desti-
nation
line
internal
internal
internal
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