The Vigor2100V/VG; 2200V/VG; Vigor2700V/VG and Vigor2820Vn routers have a Line socket to connect a PSTN phone line.
The FXS ports allow you to connect to your analogue telephone handset to the Vigor router. This enables the phone connected to your Vigor router to not only make and receive VoIP calls, but also make and receive calls using the PSTN phone line.
An incoming call on your PSTN line will automatically switch to the attached phone and you can answer the call. To make an outgoing call using the PSTN line, dial #0 then dial the number.
The phone LED indicates the current mode – Green for VoIP and Amber for PSTN.
If the Vigor router loses power, its failover mode will automatically switch your phone over to the PSTN line.