the firewall restricts traffic to familiar ports with one or more specific protocols associated with each open port. So to get stuff in and out of port 80, it needs to be http?
YES!
Is this what is meant when people say they can't use java because they're behind a firewall?
YES! sometimes is restricted to privileged ports and sometimes to the ports and specific protocol together.
The issue that comes to mind is that you can only have one service listening on a given port. So if you have AOLserver listening on port 80, to my knowledge you can't share that port with a chat server. Does that mean you would run the chat server on port 80 on another IP address?
I think this is the best solution
Or would the chat server, or some kind of http tunneling middleware, be the service listening on port 80, brokering the requests and routing them to the appropriate web/chat server?
this will be more complicated I guess, it easier to have a specific IP for your chat, more when that is very popular, maybe the chat service is running in a different machine in that case.
