Portforwarding with Xbox One and Sky SR101 router/hub.

Hello. I've got a Sky SR101, and everything seems to be fine with it when it's connected to my PC. However, my son's XB1 NAT type is strict. I've gathered that some ports need to be opened, and I've gone into the Portforwarding page in the router, but I can't seem to get my head around it.

I've tried calling Sky, but they seem to have less of a clue than what I do!

Can anyone help?

Thanks in advance.