8 ms·
Of the various internet .+P, NTP is one I never learned about as a student, so now I'm looking at its web page [1] by its creator David L. Mills (1938-2024). I
by glkindlmann 9mo ago
Of the various internet .+P, NTP is one I never learned about as a student, so now I'm looking at its web page [1] by its creator David L. Mills (1938-2024). I've found one video of him giving a retrospective of his extensive internet work; he talks about NTP at 34:51 [2] and later at 56:26 [3].
[1] https://www.eecis.udel.edu/~mills/ntp.html https://www.eecis.udel.edu/~mills/ntp.html
[2] https://youtu.be/08jBmCvxkv4?si=WXJCV_v0qlZQK3m4&t=2092 https://youtu.be/08jBmCvxkv4?si=WXJCV_v0qlZQK3m4&t=2092
[3] https://youtu.be/08jBmCvxkv4?si=K80ThtYZWcOAxUga&t=3386 https://youtu.be/08jBmCvxkv4?si=K80ThtYZWcOAxUga&t=3386
- ssl-3 9mo agoHN discussion shortly after Dave Mills died, early in 2024: https://news.ycombinator.com/item?id=39051246 https://news.ycombinator.com/item?id=39051246
- torcete 9mo agoIn [3] he mentions that one can use NTP to observe frequency deviations and use it as an early warning system for fire and AC failure. That really intrigues me. Can you actually? Has this ever been implemented?
- magicalhippo 9mo agoOscillators of all kinds are temperature dependent. That's why the most stable ones are insulated and ovenized[1]. So an AC failure which would lead to higher room temperatures would lead to stronger or more frequent correction by the NTP client, as the local oscillator would drift more. Not sure about the fire case though. I mean the same applies there but I'm not imaginative enough to think of a realistic scenario where NTP would be useful for averting a fire. [1]: https://blog.bliley.com/anatomy-of-an-ocxo-oven-controlled-crystal-oscillator https://blog.bliley.com/anatomy-of-an-ocxo-oven-controlled-c...
- eichin 9mo agoI knew of some experiments in this space back in the late 1980s or early 1990s - but it was specifically with DECstation hardware that had terrible clocks (not used for alerting, just "this graphs nicely against temperature".) https://groups.csail.mit.edu/ana/Publications/PubPDFs/Greg.Troxel.Thesis.1994.pdf https://groups.csail.mit.edu/ana/Publications/PubPDFs/Greg.T... (PDF) 4.2.1 does talk about explaining local clock frequency changes with office temperature changes (because they overwhelm a clock-aging model) but it doesn't have graphs so perhaps they weren't clear enough to include (or just not relevant enough to Time Surveying.)
- OptionOfT 9mo agoWhat do you mean by +P?
- rexreed 9mo agoLooks like .+P is just a regex way of saying any set of characters / protocol ending in P.
- juped 9mo agoNothing, as they said .+P (note the dot)
- black_knight 9mo agoPresumably, .+P is regex referring too all the acronyms ending with P, that is Protocol. SMTP, HTTP, FTP, IMAP, XMPP…
- rgovostes 9mo agoAmazingly, The New Yorker wrote an article about it: https://www.newyorker.com/tech/annals-of-technology/the-thorny-problem-of-keeping-the-internets-time https://www.newyorker.com/tech/annals-of-technology/the-thor...