The network protocol we use is udthttp://udt.sourceforge.net/udt3/doc/t-firewall.htm
The trick is that both server and viewer connect to the access server and use the external port to connect
to each other. Server and viewer are making outgoing connections...
Upnp wil not work as it map incoming ports to a specific host/port, we only have outgoing ports.
Is your firewall before or after the nat router ? Normal it should only see the internal ports 5570.5571,5572,....and not the external ports.
sorry, source is not availbe.
It's more then 10.000 lines without proper docs..
Perhaps you can convince me if you worked on other software before