Well I'm using the Worldnet megapass modem and I'm having problems finding the port-forward option. I was guessing it was under NAT and Virtual Servers Setup, I tried that but I get a error I don't have enuff number of entries left when I dont even have 1 added in yet.
Haha that ones a bit complicated... Need to first assign a fixed IP to the computer on the "lan clients" page. Then go to "virtual servers" page and select the IP number you want to edit, i think it will show any rules already set. There are 3 or 4 categories of preset forwarding rules such as games or services to choose from, and if its not there you can make a new one at the bottom (i think its custom rules). If you chose custom, find an option there to add a new virtual server, and select the type of forwarding (probably TCP) and the internal/destination ports etc along with any complicated options you need. Click apply, then go to the "Tools" menu and save the settings then click reboot. From memory the port forwards don't take effect until you reboot.
Qualified in business, certified in fibre, stuck in copper, have to keep going ^_^