Definitely suitable only for Fritzbox

similar to the manufacturer AVM Telekom is building phones that meet only on their own brand. That would not still bad, but in the prospectus is advertised with DECT functionality and "ideal with Fritzbox or Speedport" noted only in the small print on such. Whoever rashly accesses and its telephony does not unwind eg via a Fritzbox must accept losses in comfort. A bit more honesty on the part of the manufacturer's annoyance would save. Here the customer is just asked in advance!

Log in and start with the Fritzbox succeed right away. There then also all the features available, as already described, the previous speaker.
Call quality does not get beyond a Satisfactory: croaking and cracking. The loud speaker was disappointing: too low and also knarzend. What am I doing wrong?

When I registered the C4 to a "normal" DECT system, but could not make calls: no call list, no phone book, contacts can not be transferred. Too bad that the technical possibilities for this constellation no longer give. My old "bones" of Siemens or Telekom there were more playful.

For the price, I find the performance a bit thin and also with the design I'm not entirely happy: longer calls keep their hands ever clench. Why can not you handy phones build as 10 or 20 years ago?