LANCOM 1722 VoIP – LANCOM 1724 VoIP
Chapter 5: Configuring Voice over IP
86
EN
Enable the external ISDN outside line and the internal ISDN bus in order
to use the VoIP functionality. Enter all external MSNs for the ISDN outside
line in the ISDN mapping table with their assignment to the internal num-
bers in the VoIP range.
Enter all connected ISDN terminal devices as ISDN users with the follow-
ing values:
Telephone number / SIP name: This number will be assigned to the
ISDN terminal device as an "internal number". The telephone struc-
ture will remain clear if you use the same internal number for a termi-
nal device here as it uses in its own ISDN environment.
MSN/DDI: Here, enter the external MSN of the ISDN outside line
which was formerly entered into the ISDN telephone.
Enable spontaneous outside line access for ISDN and SIP users in order to
keep the subscribers' telephone behavior as consistent as possible.
The continued configuration and changes to the call routing table are car-
ried out just as in the example 'Using VoIP telephony to extend the down-
stream ISDN PBX'.
Configuring the VoIP terminal equipment
The VoIP terminal equipment is configured as described in the preceding
examples with internal VoIP domains and internal numbers for the local site.
Assigning external MSNs to internal telephone numbers
In this example, the external MSNs and the internal telephones will be assigned "crossed
over":
In the ISDN mapping table, the external MSN '555 555 1' is assigned to the internal tele-
phone number '11', for example. An external call to '555 555 1' will be switched by the
LANCOM as a call to '11'.
By assigning the MSN '555 555 1' to the internal telephone number of the ISDN user '11',
the call will be directed over the internal ISDN bus of the LANCOM with the target tele-
phone number '555 555 1'.
Because the ISDN telephone "listens" out for its own MSN, exactly as it used to before imple-
menting the LANCOM VoIP Router, the call is placed to the correct telephone.
Should the LANCOM VoIP Router fail due to a power outage, the life-line support and power
relay over the ISDN bus, if activated, enable the connected telephones to continue to function.
