well, I am using as a test the chat program that comes with delphix

Problems immediately arose with people behind routers

I looked at traffic in my firewall and discovered 2 UDP ports and 2 TCP ports in use, seemingly randomely chose

Now I have no experience with routers but I am told that to make sure, ports must be opened if the computer is hosting. How can they open UDP/TCP ports that seem to be random? (this might sound completely dumb)

More to the point can I tell DXplay which port(s) to use?

1 person couldn't join me or host, 1 person could join me but couldnt host properly.

Anyone got any experience in this?>