Java Programming

I wrote a small chat program that pairs sockets together and the server just sends the messages back and forth. It turns out that the server I have access to will not give me access to a private port to which I can bind a serversocket.
Does anyone know another good way of writing a chat program without using sockets in a webserver (Tomcat/Resin) environment. I was told that writing the socket in a command line app could solve that problem but I'm not sure how to run that from a webserver (ie - you still need to provide a port number when creating the serversocket). Anyone understand how to do this?
I heard SOAP or REST is a good way but I don't understand how it keeps track of all the client 'pairs'. Any help is greatly appreciated.