I tried tether to laptop then to box using a cross over cable and forwarding ports over Internet connection sharing. I also tried installing multiple port forwarder applications onto my phone and tethering directly to the XB. One app was meant for a rooted phone (port forward ultimate), which mine isn't and it would let me stop the process before uninstalling.
Unfortunately for me it didn't work and now the tethering speed is INSANELY slow. It tells me there is an MTU error (1340) and the games which used to work fine are now completely unplayable. I wish I had never done all of it just to play one game as the others worked fine.
I am really upset, because the bit of internet I get to play video game is barely keeping my alive at the moment and now its gone.
If you have any advice you would be helping a very ill man get a little bit of joy.