Yes...? I know that, but does that cause any issues in practice other than death of P2P?
> So if you don't have a public IP address, how exactly are you supposed to forward anything? What is the other end supposed to connect to as an IP address?
I already mentioned port forwarding because with something like CG-NAT, it is often not possible (or not allowed). But I am not aware of any issues that stem from this other than an inability for others to establish connections directly to you. In fact, my network has a public IPv4 without CG-NAT and yet I am already used to being unable to receive data other than back through a TCP stream. That is the entire reason reverse proxy tunnels (such as ngrok, etc.) exist.
Well:
> If you’re a gamer using PS5, Xbox, or PC in 2025, running into Double NAT or CGNAT port forwarding issues can make online play nearly impossible. Many 5G home internet and satellite services (like T-Mobile Home Internet and Starlink) put users behind carrier-grade NAT, which blocks direct connections and port forwarding. The good news? There are still workarounds that can open up your connection for smoother online gaming.
* https://www.modemguides.com/blogs/modemguides-blog/double-na...
See also:
* https://en.wikipedia.org/wiki/Carrier-grade_NAT#Disadvantage...
When we went from dial-up speeds to DSL/cable to fibre we were able to have all sorts new applications due to higher bandwidth. Smartphones are capable of all sorts of things because they're always online: back in the day people used to talk about "being online" and saying "sorry, I was offline", because you only had connectivity at the office or at home (where you dialed into your ISP).
What kind of applications and services are not being invented because we're stuck with the current non-P2P / centralized setup of IPv4+NAT?
I don't know? I've never had CG-NAT and yet I've never seen a piece of software that takes advantage of that except maybe for games that use UPnP to open ports.