BEagle
Look no further! Siemens do a Gigaset 675IP which is the dog's b0!!0x.
The base station plugs into your telephone line
and your modem/router.
You can then set up the system to make VOIP calls (I use
VOIPdiscount - free to landlines for three months. But you have to invest 10€ first).
It is not cheap but does everything I need. With all of those annoying marketing calls (numbers withheld) coming up on the screen, I just send them through to the answering machine......click!!
You know it makes sense!!!
Oh, and to save you doing one of those tedious searches, more info
here.
If you go for one they can be a bit tricky to set up, if you need help just shout!!