After a long (and expensive) phone call with my father, we both realized that it made little sense in our days to use a GSM network while at home.
That said we figured out that voipbuster was the best service in town: free calls, SIP based service and some of our contacts are already in this network. We could have gone with skype, but it offers a closed shop service with no inter operation besides legacy networks (PSTN, GSM).
Next task: find a hardware phone (I don’t want to be attached to a computer all day long, enough is enough!!).
Well loking into the available options the Siemens phones provided an interesting feature PSTN/VoIP dual mode. Again we had an alternative: the Linksys PAP2 which although cheaper did not had the dual mode function and did not include a phone.
That said we got the Siemens Gigaset C450 IP. For more details visit the blog in the future ;)