ATA

ATA or Analog Telephone Adaptor, is the most common way of using VoIP. This adaptor actually allows you to hook up the phone that is already in your house to your computer, and then your Internet connection. How it works is it converts the analog signals your phone sends out into digital signals that can be sent over the Internet. Setting up this system is really easy, even if you have no technical know-how.

All you need to do is order an ATA , plug the cable from your phone which would normally go into the wall socket into the ATA, and then the ATA gets plugged into your computer, which is connected to the internet. Some ATAs include software that has to be installed on your computer before its ready, but basically it's quite a simple process. Then you are ready to make some calls.

For more information on this method check out Phone Gnome here.