Can Not connect

[Geza Levai]

I am trying to connect to a Windows 2000 workstation with RealVNC v4.0 
through the Internet, no luck. The computer is connecting to the Internet 
with a Linksys BEFW11S4 Router through Charter cable.

I have port forwarding configured. I can log into the router through http, 
but RealVNC will not reach the computer. (McAfee firewall is disabled)

So, I tried to connect using the Java viewer, but I am not sure what to do. 
When I tried it, first a small window popped up with the IP address and 
port number and some config options, when I clicked on OK, the only thing I 
see is the SUN Java logo in the middle of the screen, but nothing else happens.
I am not sure, but does a Sun Java platform has to be installed on the 
destination PC as well in order for the Java viewer to work?

Does someone have any suggestion?

Geza