ej slovenac!
http://documentation.netgear.com/rp614v4/enu/202-10167-01/rp614v4-6-03.html here is how to port forward.
you need to create manual ip adress for your console and after that do the port forward. for example: your router default ip is 192.168.1.1
set ip on xbox 192.168.1.135
after that do port forward with that adress(192.168.1.135).