I think you need an internet phone line supplier too. I have Vonage - (see Vonage.co.uk) and for about £8 a month get free 24 hour calls to a range of countries - in my case UK, Ireland, Germany, USA, Canada, Australia. They do other packs. They supply a small adapter you connect to your wireless router/modem (then plug in any phone)and they also give you a (second) phone number. PC does not need to be on. There are others such as Skype. I keep a BT line in case internet or modem goes down.