@Muarrij
Yes, you do need to port forward, because the NAT if it’s smart does dynamic port routing or whatever it is called, meaning that you have to tell the router which port it has to let through to the same “real” port on your computer for incoming connections. Forward all the ports to your computer for a moment and check with the ItCan tool what ports your netmeeting session uses or consult the Microsoft support database if you are not the trial and error kind of person. The reason you are having problem is that Netmeeting does not use the same ports for broadcasting and listening. Your router would drop all incoming connection attempts on a port not previously broadcasted on by Netmeeting.