Yes, you can connect the telephone to the Tel 1 (RJ11) connection of the Technicolor CGA2121-TCH modem, as it has a standard DECT and analogue compatible connection and works with common routers and modems such as Speedport or Homebox. CLIP works, including phone number display and name display from the phone book (up to 400 contacts with Picture CLIP), provided the modem supports and transmits CLIP/CNIP. Make sure that the CLIP function is activated in the modem, then the phone will display the name and picture for matching entries.