Is the GL.iNet GL-MT300N-V2 the glue between T-Mobil Home internet and multiplayer Xbox Series X?

I apologize but networking is not my forte. I’ve just enrolled my family with T-Mobil’s Home Internet service and for us it’s bloody amazing for the price. As I sit here I just did a Speedtest between Shoreline North of Seattle to the local Starlink server and I’m getting 546MBPS down, 55MBPS up and a Ping of 25ms. It’s trivial to set up and it has been supremely reliable for the past two weeks. It only has for us one problem. Our Xbox’s reliance on IPV4 and UPNP for multiplayer gaming. The fact that the T-Mobil version of the Nokia Gateway/Modem/Router is IPV6 only renders multiplayer, well unplayable. Could this little yellow box be configured such that it would use a fast VPN service to tunnel to a local VPN server with the required IPV4 protocol carrying UPNP with it. As long as the latency doesn’t get above say 45ms that would be great. Paying for a VPN service on a long term contract would be far more preferential than slinking back to the hated Comcast. This solution would only be Ethernet based so no wi-fi involved. T-mobil have apparently got millions of these installed so I know I’m not the only one that has this problem. In fact a baked in solution would sell like hot cakes because the T-Mobil forum haven’t a clue how to deal with this.

You mean T-Mobil does not provide ipv4? It is hard to believe.

Yep, it’s true. They use a translation tool within the modem (I think). Here’s some info on the subject scraped from the T-Mobil forum itself;

Since TMO’s network is an IPv6 network, I’ve figured out that a translation technology (464XLAT) is implemented to provide IPv4 connectivity to users, this is a common technology for this purpose. However, this solution translates many users into a pool of IPv4 addresses rather than providing a 1:1 IPv4

I don’t know how any of this works but it makes sense as to why IPV4 is so sketch on high demand services like gaming. Looking at the T-Mobil user forum there seems to be a lot of IPV4 related issues. From what I understand T-Mobil have limited the functionality of 464XLAT so that protocols like UPNP (amongst others) is borked.

It is worth to try. But you may need a vpn service that allows you to do port forward.

Install 464XLAT, 464xlat will provide clat service on the router, automatically start nat46, and find the superior plat service, but the automatic effect is not very good, you can manually add the configuration.
You can add under the /etc/config/network file, configure as follows,

config interface ‘wan6_4’
option proto ‘464xlat’
option ip6prefix ‘dd50:e735:b42d:1111::/96’

and then execute cmd: /etc/init.d/network restart
Option ip6prefix is just an example. This is the ipv6 prefix of a NAT64 server. It is usually provided by the operator. You can ask the operator.