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NIST was 5 μs off UTC after last week's power cut

jeffgeerling.com

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Re: NIST was 5 μs off UTC after last week's power cut

#131

Post by nottorp »

voidUpdate wrote: post #125

Maybe I missed something, but I don't quite understand the video title "NIST's NTP clock was microseconds from disaster". Is there some limit of drift before it's unrecoverable? Can't they just pull the correct time from the other campus if it gets too far off?

I'll consider it clickbait...

... unless someone with real experience needing those tolerances chimes in and explains why it's true.

Re: NIST was 5 μs off UTC after last week's power cut

#132

Post by voidUpdate »

nottorp wrote: post #131
voidUpdate wrote: post #125

Maybe I missed something, but I don't quite understand the video title "NIST's NTP clock was microseconds from disaster". Is there some limit of drift before it's unrecoverable? Can't they just pull the correct time from the other campus if it gets too far off?

I'll consider it clickbait... ... unless someone with real experience needing those tolerances chimes in and explains why it's true.

I'd have thought Jeff to be above clickbait, but here we are

Re: NIST was 5 μs off UTC after last week's power cut

#133

Post by anilakar »

mmaunder wrote: post #65
semenko wrote: post #51

I found the most interesting part of the NIST outage post [1] is NIST's special Time Over Fiber (TOF) program [2] that "provides high-precision time transfer by other service arrangements; some direct fiber-optic links were affected and users will be contacted separately." I've never heard of this! Very cool service, presumably for … quant / HFT / finance firms (maybe for compliance with FINRA Rule 4590 [3])? Telecom…

SIGINT as a source clock for others in a network doing super accurate TDOA for example.

But they do not need absolute time, and internal rubidium clocks can keep the required accuracy for a few days. After that, sync can be transferred with a portable plug, which is completely viable in tactical/operational level EW systems.

Re: NIST was 5 μs off UTC after last week's power cut

#134

Post by nottorp »

voidUpdate wrote: post #132
nottorp wrote: post #131

Earlier quoted context omitted.

I'll consider it clickbait... ... unless someone with real experience needing those tolerances chimes in and explains why it's true.

I'd have thought Jeff to be above clickbait, but here we are

The web article title doesn't mention any disaster. I don't see the embedded youtube video - probably have to many privacy options on.

Re: NIST was 5 μs off UTC after last week's power cut

#135

Post by squigz »

esseph wrote: post #91
semenko wrote: post #51

I found the most interesting part of the NIST outage post [1] is NIST's special Time Over Fiber (TOF) program [2] that "provides high-precision time transfer by other service arrangements; some direct fiber-optic links were affected and users will be contacted separately." I've never heard of this! Very cool service, presumably for … quant / HFT / finance firms (maybe for compliance with FINRA Rule 4590 [3])? Telecom…

I'm sure all of that is true, but so is "Department of Defense". They're also the largest holder of IPv4 space, still. https://bgp.he.net/report/peers#_ipv4addresses

Why does the DoD hold so many IPv4s?

Re: NIST was 5 μs off UTC after last week's power cut

#138

Post by asdfman123 »

ambicapter wrote: post #79
ziml77 wrote: post #50

Nitpick: UTC stands for Coordinated Universal Time. The ordering of the letters was chosen to not match the English or the French names so neither language got preference.

That's an interesting rationale.

The trick is making sure no one is happy with the final outcome

Re: NIST was 5 μs off UTC after last week's power cut

#139

Post by asdfman123 »

voidUpdate wrote: post #125

Maybe I missed something, but I don't quite understand the video title "NIST's NTP clock was microseconds from disaster". Is there some limit of drift before it's unrecoverable? Can't they just pull the correct time from the other campus if it gets too far off?

You'll never guess why. The answer might shock you.
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