Hello Mark,

ISDN audio codecs don't need a special ISDN line - just a bog-standard ISDN line is enough. Of course you will need to have the "data service" enabled with your provider (but since you've been using the line for web streaming I presume that you already have this). Depending on your provider you may also need to have long-distance calling and long-distance-data service enabled - unless all your calls will be local of course!

AudioTX Communicator will indeed be right for this setup.  It is compatible with the equipment from all major ISDN codec manufacturers like Musicam USA and Telos. The sound quality mainly depends on the sound card that you will be using with the software. With a professional sound card you will be able to do high-quality audio sessions. 

Feel free to have a try with the program yourself - you can download a demo version from the website -  Multimedia File Viewing and Clickable Links are available for Registered Members only!!  You need to or .