Is it possible to achieve open NAT (Type 1) on my PS4?

Question

I have the Huawei B5142 device from my carrier. This device is the source of internet connection to my home's router. My PS4 is wirelessly connected directly to the Huawei device, bypassing my router. The Huawei device has a public IP address such as 196.210.3.4, and an internal address such as 10.15.3.11, my PS4 has a standard 192.168.1.50 address reserved for its MAC address.

I should note that my ISP currently uses NAT444 / LSN (Large Scale NAT), however the public and router internal addresses (196.210.3.4 and 10.15.3.11) are static allocations from my ISP's network.

I have de-activated the router's built-in firewall and DMZ'd my PS4's internal address (192.168.1.50), yet I still get a moderate (Type 2) NAT result.

Is there something else I can try or is an open NAT type even possible behind CGN?

Answer 1

I'd personally doubt it*. As far as I can understand, Open NAT 1 status on a ps4 means you're using a Public IP address (as in not within any of the 3 private IP ranges) and the PS4 can connect seamlessly with some unspecified sony servers (I say unspecified as sony themselves don't specify exactly what you need to be able to connect to and I've never sniffed the traffic to try and check).

More importantly, as long as you have NAT Type 2 showing, this means you can connect with all other players with no issues. This is achieved generally via port forwarding on your router or placing into a DMZ as you've already done.

*I've never actually seen a system that is connected Type 1.