Question : ActionScript socket port

Hi,
I use ActionScript code to communicate with TCP server (that I wrote in .Net)
_global.socket = new XMLSocket();
_global.socket.connect(IP, port);
I use port = 13000.
Everything works fine.
But in some other computers, I cannot achieve connection.
I suppose it is because of firewalls.. that "block" this port. Right?
Can you suggest me other port number to use such that I will not have this problem?
Notice that I already use at the server (listening) side the ports 80 and 443.
Thanks, Aryeh.

Answer : ActionScript socket port

sorry can't help you with that.
on our networks and my clients, generally all ports are closed except 80 and 8080 unless explicity open.