Yes the best way is to use a external modem that has a serial connection to your computer. When doing this you can use the visa serial functions to sent your "at" commands. You then can detect dtmf tones. Usually the modem manufacturer has a good listing of the commands. The problem comes with the voice connection. To bring in the voice you might have to do some conversions using the sound palette. This is where the problem comes in converting to and from stereo or mono signals. The best way is to exeriment with the functions in the palette with just using a microphone to record a voice. Hope this helps.
