Lancom LC-1823 Manuals page 21

LANCOM VoIP Routers: PBX Functionalities
Chapter 3: Configuring the VoIP functions
20
For each ISDN terminal device that is connected, you can define the
corresponding internal telephone number and the associated external
MSN or DDI. At the same time you select the ISDN interface that the
terminal device is connected to.
If your model has analog interfaces for connecting analog terminal
equipment, you can select which of these interfaces are to be used for
connecting internal terminal devices.
For each analog terminal device that is connected you can define the
corresponding internal telephone number. At the same time you select the
analog interface that the terminal device is connected to. Please ensure
that you also select the device type: 'Phone', 'Fax' or 'Phone and/or fax'
(in case you have a combination device or if phone and fax are connected
to an analog adapter).