Previously had a Speedport 921 and 2 500 Speedphone Telekom. This ensured a very good call quality. Due to the change: I could not access it from outside on my QNAP with the Speedport. Were acquired Fritz! Box 7490 and 2 Fritz! Fon C4 The Fritz! Box 7490 met my expectation. The Fritz! Fon C4 was good in your hand, is lightweight, has a large display and a long battery life. But that was before. The transfer from my old phone book has worked wonderfully. For me incomprehensible: no separation between surname and first name. Also company name does not know the thing. Are they at the company. AVM only engineers in the development, the register of their interlocutors only first name or a nickname in the phone book and know no company? That could be changed and implemented with security without great expense. But AVM still sets it to the extreme. Making calls is only possible in the immediate vicinity of the Fritz! Box. Moving or walking around is not synonymous. Immediately a cracking start with the interlocutor, calls with me is almost unbearable for them. On your own telephone (C4) one does not notice. Conclusion: friends call me on my mobile phone number. The C4 is actually there and just looks good. Unfortunately, I will be too late become aware of all this. After each update of AVM and there's already been so few, I hope to improve. That's the state of affairs on 01 May 2015, the Fritz! Fon C4 Version No. .003. NOT BUY recommendation