NAT TYPE

What have you tried? Usually, opening your NAT involves some port forwarding from your router.

You will need to figure out how to access the settings of your router. Once you do, you will need to:

1. Set up a static IP for your Xbox One.

2.
Assign the proper ports to your Xbox One's static IP address.

Hope this helps!

UPnP may still be engaged. There are three conflicting settings in a router; UPnP, Port Forwards/Port Triggers and DMZ. Make sure to have only one of those set.

Check out our NAT Guide:
forums.xbox.com/.../34069.aspx

port forward, port trigger, upnp, or dmz (only one, disable the others or verify disabled by default.

If you use port forwarding or port triggering use port 3074 and also 3075 and 3076 (last two are specific to cod games)

DMZ will provide the lowest latency and is easiest to setup.

Regardless of what you use unplug router/ turn off for 30 seconds then turn back on, and do the same with the xbox.

Also make sure to setup a static ip/ reserved ip in the router dhcp (if that is what you use)

@LethalSniper007 - Sorry! Just noticed that you've already started one. My bad.