Port forwarding Technicolour NH20T

[wireless]

I've been trying to open a port to run a server from my computer. From what I understand, it's as simple as going into "WAN Services", clicking show advanced, and adding the port. Unfortunately, the server isn't joinable and https://www.yougetsignal.com/tools/open-ports/ shows the port as closed. Reading the forums a bit and most/all of the issues that have been passed around don't apply here, as far as I can see.

Any help would be helpful :]


More...