How to work on VOIP, Video Conferencing, Chat room using either intranet or internet system

[CoderForEver]

Hello my friends. After thinking a lot about what to do for my Senior project, I decided to work on an application which will have, Chatting system, VOIP, File transfer, and if possible Video Conferencing. My friends and I planned to do the system for INTRANET System only. It is because we thought it will be more difficult to do it using internet. By the way, do you think broadening our scope to internet system rather than intranet system will need an agreement between the Internet Service Provider? That is what we are afraid of. If it is in intranet system, we have planned to use one Server in the network and as many as clients, so they will have static IP address and it will be easy to identify who logs in or out every time once that IP is registered on the server. But how is that implemented on internet system? We have no clue about it. Please give me some links and other suggestions to start our project. Although, we have tried to see some applications like Video Conferencing and VOIP in the code project’s articles. If there are any, please help us. Thank you.