This is correct. You need to find your routers id number and type it into your address bar and change the settings. You can find everything you need on google. just type in "change NAT from closed to open". It also could be something with your firewall. Check your settings in your firewall to make sure the xbox connection is allowed.
Those are basically the same thing, but you need to check both so your router will allow the xbox to connect to the internet through your router.