When I first set out to write telephony applications using Microsoft's Telephony API (TAPI), I immediately found the amount of resources available (both online and offline) woefully short - or atleast hard to find. Microsoft's MSDN site IMO is useful more as a point of reference than anything else. So I decided to do what little I could to set this wrong right.
What follows is a little tutorial on how to make the API do some basic things like making a call or receiving one. It should be remembered at all times that the source code and the comments given here are a result of intense and at times excruciating experiments with my rather pitiful little computer and therefore are prone to the attending risks of the same :). Also this by no means is a complete reference to the API.
First, why TAPI? There really is only one good reason - portability. The API aims to be as generic an interface to telephony as possible. What this means is that when you write telephony applications using TAPI, you can be fairly sure that it will work on every system in the world that runs Windows and has telephony devices attached to it. You would write TAPI applications for the same reasons that you would write Windows applications - a really large client base and hardware independence.
We'll be looking at TAPI version 2.2 in this tutorial. Microsoft has also released a COM based interface to TAPI as version 3.0. But we won't be delving into that. You can however find material on it at Microsoft's MSDN site. You can find more TAPI links at Michael Dunn's TAPI Page.So then, lets get down to business and set the ball rolling!