Hi. Consider the typical chat application (a panel which lists all active users , text field to type into, a panel which displays all posts). This applicatin is implemented as a Swing application. Now this chat application should support VoIP according to : When a user talks (using the microphone),all the active users should hear what he says. My questions are : 1. How to collect the voice input from the user ? (using Java Communication API) 2. What to do with the uploaded voice (save it for example) ? 3. When the voice is transmitted to users, how to play it ? 4. Any open source libraries that I can make use of them ?