having worked on IP geolocation in the past, I don't think this works.
Though it can do a pretty good job of getting you in the right continent.
* Not all traffic goes through fiber - there are microwave links operating closer to the speed of light, though these are mostly reserved for high-speed trading. There's also satellite connections, but as long as they don't do satellite-staellite, they're slower.
* There are middleboxes messing with traffic, especially TCP, which add delay.
* If you rent servers in datacenters, you might not really know where they are. We had VMs relocated without our knowledge.
* Fibers links aren't direct, they tend to follow public right-of-ways. In much of the US, that's a rectangular grid along the highway system (look at a road map of the midwest sometime), increasing the delay by √2.
* Internet routing isn't shortest-path. It's get-this-crap-off-my-infrastructure, aka hot-potato.
* Anycast prefixes have IPs in multiple locations.
My experience was that with a lot of observation points, you could get within 10ms, 1000km in most places.
* Not all traffic goes through fiber - there are microwave links operating closer to the speed of light, though these are mostly reserved for high-speed trading. There's also satellite connections, but as long as they don't do satellite-staellite, they're slower.
* There are middleboxes messing with traffic, especially TCP, which add delay.
* If you rent servers in datacenters, you might not really know where they are. We had VMs relocated without our knowledge.
* Fibers links aren't direct, they tend to follow public right-of-ways. In much of the US, that's a rectangular grid along the highway system (look at a road map of the midwest sometime), increasing the delay by √2.
* Internet routing isn't shortest-path. It's get-this-crap-off-my-infrastructure, aka hot-potato.
* Anycast prefixes have IPs in multiple locations.
My experience was that with a lot of observation points, you could get within 10ms, 1000km in most places.