if your friends computer is behind a NAT then the only way you can connect to them is if they have that NAT set up to route your particular application port to their machine. otherwise you are out of luck.

the way chat programs work is that everyone is aware of the central server''s IP address. when you log onto AIM or whatever, you make a listen connection out to the main server. when you send a message, you send to the server and then the server sends your message down your friends listen connection. i imagine that every message you send has some sort of id number associated with it that the server uses to send a message out the correct pipe.

NATs are used as dumb firewalls b/c they by default don''t route any incoming data to any of the internal computers unless they are speciffically told to route a certain port to a certain machine. you may be able to config the NAT to broadcast all incoming data on a specific port to all the machines inside, but i''m not sure about that. my NAT box doesn''t allow that.

basically you need a central server that is not behind a NAT to control everything.

-me

quote:Original post by Evil Bill
How do other games do it?

incedentally games do it the same as chat progs w/ a central server. that''s why you can''t host a game server unless you are either outside of a NAT or have opened all the proper ports on the router to go to your machine.

trying to set up your NAT to route ALL the proper game ports to your machine can be a nightmare.

-me