I'm working on a trivia game that is similar to buzztime that you might play at Buffalo Wild Wings. To play the game, your smartphone connects to a Java applet that is running a TV version of the game, and then you can press "a" "b" "c" or "d" to answer a question shown on the TV.
In the environment that we will be playing this game in, the computer that is displaying the questions on the TV won't be directly accessible via a public ip address because it is connected to what is essentially a router.
I don't really know much about how UPnP works. What do we have to do to get the phone to be able to communicate either over TCP or UDP to the TV computer, and vice versa?