I haven't played with any of these usb-to-rj11 in a long time but from what I do recall it is picked up as an audio device. That way a regular telephone can be used for mic/speaker for a softphone. Given that you should be able to get audio to/from it using portaudio for starters. Pretty basic and doesn't take advantage of all the features but it would be at least a place to look.<br>
<br>-- W<br>