Last update: March, 3rd, 2006
What is the advantage?
I didn’t really like that I had to use a headset when I wanted to call someone via the internet. The volumes of the soundcard had to be adjusted to avoid over- or undermodulation. With the way described here, it is possible to use an ordinary ISDN telephone (at Germany’s Ebay you easily get one for 30 EUR) to make phone or internet calls with the help of a computer and a SIP provider. The audio quality is excellent with a DSL connection, there is no noticeable difference compared to a normal phone. The line should be clear however.
Additionally, you save the money for buying a SIP phone which costs about 100 EUR at this moment. Over the internet, you can call each other for free with a “real” phone. Calls to the Germany phone network cost 1.79 euro cent per minute with Sipgate.
This how-to is written especially for Sipgate accounts. However, you can easily adopt it for other SIP providers. You find links to other providers at the end of this document.