The Connect Box from UPC has two analogue ports (https://www.upc.ch/de...) for digital fixed network telephony and the Gigaset can also be used with analogue connections (https://www.gigaset.com/ch_de...).

The "Gigaset Comfort 550 HX" telephone is only the "mobile" part. It communicates wirelessly with a corresponding DECT base station from Gigaset (e.g.: Gigaset Box 100; Gigaset Comfort IP Box) or a DECT router.

The device is plugged directly into the Connect Box of your provider using a cable (which is probably supplied). Wingo works for me without any problems.

The telephone is placed in the charging cradle to charge the battery. For telephony we use a base station from Siemens (Gigaset Comfort 550 A IP (CH version)) with the same handsets. ATTENTION: needs a SIP address (can be obtained from your provider).
Good device, recommendable.