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.
I work for IPinfo, and we run active measurements through hundreds of servers. Allow me to highlight the fantastic points you made.
> 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.
That is a valid point. In that case, we have to fall back on the geofeed, WHOIS, or other methods of geolocation information. We are actively researching this area, though.
> There are middleboxes messing with traffic, especially TCP, which add delay.
This accounts for some problems but not all of them, as we have multiple servers running active measurements on individual IP addresses.
> If you rent servers in datacenters, you might not really know where they are. We had VMs relocated without our knowledge.
That is normal. At the scale at which we operate, server location validity is extremely important. We run daily checks and actively flag these issues. If things don't add up, we communicate with our vendors and try to understand whether it is a network-related issue or something else.
> Anycast prefixes have IPs in multiple locations.
Yes. With anycast IPs, we have hints of all their available locations, but when it comes to picking one, we default to the ASN-reported location.
> My experience was that with a lot of observation points, you could get within 10ms, 1000km in most places.
We have been significantly reducing the number of ASNs where we have high RTT by getting a server "networkly" close to them.
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I understand that this is not the absolute best location system possible, but within the scope of our industry, we are miles ahead of everyone else. We are continuously investing in research and infrastructure to improve our data even further.
It's really not. The microwave links got decommissioned everywhere because nobody NEEDS that higher fraction of lightspeed. High speed trading is the only field where saving a singular millisecond is economically rewarded. The links used by high speed trading are the only ones left.
Sure, but if it becomes ubiquitous, web devs will assume lower latency. That wouldn't make it less sad, just makes different people sad - my first guesses are those at crowded areas with overloaded cellular connections, and Australians.
Are you sure it'd only be accurate up to 1000km? I'm not as experienced but would have assumed that by sampling a dozen times, you would have at least 95% likelihood of a 100km radius
while it's unlikely you'd allocate a memory array[2^30] on a 32-bit machine, I also use binary search on mmap'd files.
Specifically, text files. Binary search doesn't need the exact midpoint, just somewhere nearby, so I pick the midpoint and look around for line boundaries.
On normal sorted text files, this works fairly well. I was able to search a list of a billion IP addresses while touching only a few pages.
Real numbers aren't based on measuring objects in space, they're an abstract construct that happens to work a lot like measuring space, at least on our scale.
You're free to reject the real numbers as a valid construct (intuitionist math), but you'd give up a lot else as well.
What do you give up when you stick to rational numbers apposed to real numbers when dealing with nature? I could see some things like pi would point to real numbers but in nature we will never get "exact" measurements anyway. Are there any physical models that only use rational numbers?
I am not a scientist. I do enjoy hearing about it though.
That's sort of from where I arrived at the propsed question as is; what examples of perfection exist so far as we can ascertain? Infinite in and of itself is a sort of "perfect" in its unobtainability, as is perfect 0° pure Kelvin, and with 0, we only ever can get infinitely closer. Perfection is in pi (I believe) perfect circles. It's what I call the undefinable quantity, or the unaccountable unit. None of this is novel but I think the connections are, between fields.
(from someone outside the social media/cryptocurrency/metaverse/AI/ hoopla)
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