71–80 of 129 posts
What RTC drifts so much in a week (or even a year) as to throw off lighting or HVAC controls timing?
An RTC chip without temperature compensation in an extremely variable temperature environment.
45 minutes in a year is under 1 part in 10000.
It's pretty cheap to embed a tiny GPS receiver and crappy chip antenna these days. Probably enough for time sync in many situations.
Is it? The cheapest gps chips are still a couple bucks a pop (not counting the extra costs of more complex integration.) And from my experience these cheap gps and pcb antenna solutions are basically useless indoors. NTP is probably still the right solution for these devices, being essentially free to add to a device that already needs an internet connection. Care should just be taken to implement it correctly, obvio…
This is true. I know a TV station that has a tiny satellite antenna bolted to the outside wall to run its internal NTP for all of its wired and wireless devices because GPS simply doesn't work inside the building.
I'm not sure if that's a problem because of all the electronic equipment, or the construction of the building, or the fact that the building sits almost underneath a 500-foot-tall tower with several 10 to 20KW transmitting antennae on it.
Earlier quoted context omitted.
I don't think that was really the main problem in this case. Hardcoding any address (DNS or IP) that you do not control is always a horrible idea.
Does anyone really control their IP addresses? I thought that ultimately those were controlled by ARIN, RIPE, et.al.
But it's true that newcomers these days can't truly "own" their own addresses.
Earlier quoted context omitted.
On the one hand, I completely appreciate this. When I set up NTP, I'm careful to think through consequences and tread lightly. After all, I learned my sysadmin skills at a university before the September that Never Ended, so it really was a collegial place back then. On the the other hand, the internet is a much bigger place. Things are orders of magnitude more complex. The feedback loops that made NTP work well in a…
I do agree. A complete solution is designing a new generation/revision of time protocol with accountability and anti-misuse as parts of its design, just like how people are implementing ASLR and NX in C programs and starting to use memory-safe languages. Or just see how TLSv1.3 removed all unsafe algorithms, so it will be little damage even under the worse case scenario. Also, I think NTP needs more publicity. We nee…
It would be "time.google.com" and you would need a Google account.
It’s so simple to setup your own Stratum-1 server, I don’t get why more folks don’t. The one I keep in my house is a 1U unit about the size of a 16 port switch and keeps time accurate to 15ns via a small Multi-GNSS antenna (yes, serious overkill for home needs, but I already owned it for a use case that used to need it).
Unfortunately, having more Stratum-1 servers does nothing to help clueless device manufacturers who hardcoding the IP address of an individual server, and damaging the community service. But yes, when we talk about the NTP community in general, we certainly needs more Stratum-1 servers. Nowadays, running a Stratum-1 is easy, the hardware is cheap, a single broad computer w/ time source from a shortwave radio or GPS.…
That would definitely not be Stratum-1, so I wouldn’t recommend it.
Earlier quoted context omitted.
Unfortunately, having more Stratum-1 servers does nothing to help clueless device manufacturers who hardcoding the IP address of an individual server, and damaging the community service. But yes, when we talk about the NTP community in general, we certainly needs more Stratum-1 servers. Nowadays, running a Stratum-1 is easy, the hardware is cheap, a single broad computer w/ time source from a shortwave radio or GPS.…
> a good way is using the time provided by mobile basestations That would definitely not be Stratum-1, so I wouldn’t recommend it.
Earlier quoted context omitted.
I do agree. A complete solution is designing a new generation/revision of time protocol with accountability and anti-misuse as parts of its design, just like how people are implementing ASLR and NX in C programs and starting to use memory-safe languages. Or just see how TLSv1.3 removed all unsafe algorithms, so it will be little damage even under the worse case scenario. Also, I think NTP needs more publicity. We nee…
designing a new generation/revision of time protocol with accountability and anti-misuse as parts of its design It would be "time.google.com" and you would need a Google account.
Good a place as any to mention my short story https://slashdot.org/comments.pl?sid=7132077&cid=49308245 possibly the only work of fiction ever inspired by NTP, IoT and cryptographic protocols. This struggle with embedded ip address seems to echo this part of my story, "These hastily made things flooded the market and soon replaced other well-documented things. At times something failed and its inventors could not say…
Question for people who read the link- Do you like the writing style and inclusion of gifs?
I enjoyed it. Is it practical for you to only play the animations on mouse over, and pause them otherwise? I think that might allow us the entertainment value of the gifs, without the annoyance of them looping endlessly while we're trying to read.