So basically VOIP is “cheating” because its not actually handled by the network directly, the phone company pays for always-online servers, and phone(s) reach out to those server every time they change networks, in order for servers to be able to route calls to them.
Which also means! it is possible to do the same thing for computers, but it requires having
A static IP
An always online server
The device needs a daemon that tries to connect to an always online server, and authenticates itself
That server needs to manually reroute traffic (through a VPN or some other means) from the static IP address to the device, wherever it might be
Which also explains why general network providers wouldn’t want to create the infrastructure. Even if universal addresses were given to each device, which simplifies DHCP and address-leasing, and shortens time it takes to handshake with the network, all of that is less of a cost than the infrastructure needed track of devices as they change networks. (And that’s on top of ISP’s being slow to change from the legacy approach of local networks and desktops).
^ which is more the conversation I wanted to have but didnt really get with this post.
Thats a sizable edit!
Yeah 😅 I didnt want it to be this complicated of a question, but I didnt see how else to explain that current addressing systems don’t meet the same need as a phone number.