JMF Audioconference with PC in a LAN

[Jesus Fernandez]

Hi there,
i have an audioconferencing JMF application that works between PCs if i know their IPs, but ...
when i try to connect between a PC in a LAN that conects to Internet through on a router, i dont know its IP. I just known router's IP, and it doesn't work.
I solved the problem modifying configuration of the router, basically with NAPT, using port forwarding in the router. You can say the router that all incoming UDP data through a port xxxx from external PC was forwarding to a node with its IP LAN 192.168.0.xxx through a port yyyy
But this is not a good solution because the application's users usually dont allow to access the router
Any suggestions?? I think Messenger and Netmeeting use a code to scan free ports or anything else.
Thanks in advance