I doubt that the client tells the server what port it's on. IP Masquerading (read NAT) would fail for more than one client behind it. However, you can play conquer on multiple computers behind a NAT. Also, the RFC standard for NAT says nothing about what external port must be chosen for a connection. It is weird that you are getting "Bad Connection" problems. I have also been getting these recently with the actual CO client (and my bot, but that's a different story) so maybe it isn't the proxy's fault. If you would like, I could help you figure out what is going on. I also have an idea for a project somewhat like this. PM me if you're interested.