Thanks, a detailed for sure checked tutorial would be super...
1)First you must have access at your routers (at the side they are, from the pcs)...
2)Login on the router(s) with username/password
3)Firewall, PortForward, NAT, add the local ip and the port in and out (usually the same) - or simple DMZ (must be as option at the router) the local ip address
4)Do the same at the other router
5)At windows / Firewall... add the exe(s) of b4j folder to have incoming/outcoming (Advance Firewall settings) at both pcs...
or if you have 3rd Antivirus I/S... do it at the Firewall Settings...
ps: Also inside any of your two LAN's you must not using dynamic ip (dchp)... but have static IPs...