NAT (Forwarding) in T-Mobile Gateway

I agree TMobile could have made this much easier by providing an internet facing IP address, as well as IP scope control and other things. But there are easy ways to get your setup working if you have another router.

To start, just have another router and connect either of the yellow ports of the TMobile gateway connected to the internet port (WAN) of your router. Now you have complete control over your internal network with DHCP, Scope, Static IPs if you want, Firewall rules for the internet, etc.

The next thing is to use something like the free version of TeamViewer, which will create the path through the internet to your computer for remote access and you can remote into your computer from outside the network whenever you want.

For security system viewing, just setup the viewing app on your home computer (which you probably already have) and remote into your computer and view your cameras that way. TeamViewer has a version for Windows computers, phones, tablets, Linux, MacOS, Raspberry Pi. So pretty much any device you have.

I know this is a workaround for T-Mobile's lack of services on the gateway, but it works great, it's reliable, it's a free solution, and restores functions many people need. It's also only takes a couple of minutes to setup. I use it all the time and I have no issues. I'm sure you could do this with other remote services that are available, but I prefer TeamViewer over many of the non-trusted remote services available.

Good Luck