>We want to use CTI in our application. Which software shall we use or makes it sense to use the tapi.dll (then it would be helpful to have an example)?

Karsten,

I don't know how much help this will be, but in the 1998 Microsoft Periodicals there was an article titled, "For the Telephony API, Press 1; For Unimodem, Press 2; or Stay on the Line" by Hiroo Umeno. Part of it deals with the "whys". It also references where you can get the on-line code samples. The article is part of the October, 1999 issue of the MSDN library.