I’m shocked this answer has so many upvotes. No, a MAC address is not close to a phone number. No two people have the same phone number, and I can’t just edit my phone number to be someone else’s number.
“two network interfaces connected to two different networks can share the same MAC address”
“Many network interfaces, however, support changing their MAC addresses”
Yeah I was lazy with saying ipv32 just to mean something excessively long. I didnt want to say ipv6, since I kinda think it needs to at least be 64bits (edit: ipv6 is actually 128bits), and really for a public-private key pair it should be larger, so more like 512 to avoid anything like the v4 v6 cacatestrophe again in 20 years with post quantum forms of asymetric key challenges. But I didnt feel like writing all that out.
I’m with you. I knew I’d get people not reading and say “that’s the ip address”, but MAC address? 🤦♂️
I meant “in the same way that phone numbers are unique to phones (not perfectly unique, some phones have dual Sim, some have no sim, sometimes a Sim changes numbers after contacting the provider, etc)”
Its just typing all that^ in a title is kinda long.
EUI-64 IPv6 (and why its not a reality) though is kinda what I’m curious about. But not really because, even under that spec, its still not static like a phone number. I want to know why networks were not created in a way where I can send a message to a laptop regardless of what WiFi its connected to (assuming it is connected and online).
Same people who decide phone numbers and domain names. We already have central registries, why does it being a computer make it harder to have a central authority?
If I were an engineer in the past, trying to send a message back to an endpoint (e.g. a server response) I would’ve reached for everything having a static IP, same as the EID system with phones, instead of the DHCP multi-tier NAT type system with temp addresses.
I’m all but certain they didnt do it for privacy reasons at the time.
Sure, I’ll change the title to say “phones have unique phone number (b/c sim cards), why don’t computers have an equivalent?” I didnt mean one phone == one phone number.
With VOIP I can get phone calls even without cell service, even behind a NAT. My question is why is the network designed in such a way where that is possible, but I can’t buy a static address that will persist across networks endpoint changes (e.g. new wifi connection) such that I can initiate a connection to my laptop while it is behind a NAT.
The IP doesn’t persist across network hops (cell tower to cell tower) and the MAC address doesnt have one verified owner. A phone number is both verified having one owner and persists across network hops.
AFAIK static public-facing IP addresses are limited to a physical location. It would work if my laptop never left my house but as soon as I take it to the airport its no longer accessible. People who try to connect to the static ip would just get a message saying the address timed out.
Fair, I could have said fully qualified number, including country code.
And also fair, instead of saying a MAC could be edited, I should’ve said each phone number has one global owner, while each MAC address could have many owners.
This I’m interested in, because its at the edge/limits of my knowledge when it comes to domains and cellular networking.
Are you saying if cell phones had a larger address space, let’s say 32 digits base 10, and every device was given a cell phone number, it would overwhelm the existing infrastructure?
You’re right it depends on the definition of phone number, and I edited the original post to try and be more clear that I meant the phone number including the country code and area code.
If you’re talking about something other than country/area code though, then that’s news to me.
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.
If I’m understanding correctly, you’re saying that right now the network doesn’t have an exhaustive table of IP addresses to physical locations. It has a cache, and a hierarchy, and the path to a location of the IP is fluid.
But a system where every device could be directly contacted/identified like a Sim card, would effectively require a complete table of “what network is device ABC at”. A table that is updated every time the device changes network connections. It would be like trying to change domain name to point to a different IP address.
The problem is, updating a domain to point to a new IP takes hours or days not seconds, so doing that every time a phone changes WiFi is not practical.
Thank you for such a long and detailed post! I indeed did not know about things beyond the SIM, and I didn’t know about the extra details about the country codes either. That is extremely interesting to me.
With the phone spoofing though, does that mean two factor with a phone number is basically useless? If I had authentication based on a MAC address, it would take seconds to break it. But I think, and sure hope, that auth based on phone numbers is more secure.
I think your domain name answer – that for the most part computers didnt need them – is a very satisfying answer.
Why don't computers have "computer-numbers" equivalent to phone numbers
Why doesn’t every computer have 256 char domain name, along with a private key to prove it is the sole owner of the address?...