For me, on stuff t&t, you go to 192.168.1.254(your router's IP, it probably will be different for you), then wait for the horridly loving slow router website to load, click on the settings tab, then firewall, pinholes, add the port you want("add user-defined application"), fill that out, then select your computer, go to the user defined thing, click on what you named it, then click on "add". Probably will take you 10-15 minutes due to the slow-as-forget router page.
What can you expect. It's a router, not a web host.