This is the list of all the telephone lines (PSTN and VoIP) currently configured for use.
They should include all voice modems or professional telephony devices as well as all of the VoIP lines that you wish to use.

Add a new telephony line device or VoIP (SIP) line. See Telephony ~ Add Device.

Removes the selected line device from the configuration.

Change the properties of the selected line device. See VoIP Help - Account and Hardware Help - Line Properties for more.

See also:
Settings