alt Hacker News> Such precision is important for scientific applications, telecommunications, critical infrastructure, and integrity monitoring of positioning systems. But this precision is not achievable with time transfer over the public Internet
How do those other applications obtain the precise value they need without encountering the Internet issue?
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A lot of organizations also colocate timing equipment near the actual clocks, and then have 'dark fiber' between their equipment and the main clock signals.
Then they disperse and use the time as needed.
According to jrronimo, they even had one place splice fiber direct between machines because couplers were causing problems! [1]
If you must use the internet, PTP gets closer.
Alternate sources include the GPS signal, and the WWVB radio signal, which has a 60kHz carrier wave accurate to less than 1 part in 10^12.
> How do those other applications obtain the precise value they need without encountering the Internet issue?
They do not use the Internet: they use local (GPS) clocks with internal high-precision clocks for carry-over in case GNSS signal is unavailable:
* https://www.ntp.org/support/vendorlinks/
* https://www.meinbergglobal.com/english/products/ntp-time-ser...
* https://syncworks.com/shop/syncserver-s650-rubidium-090-1520...
* https://telnetnetworks.ca/solutions/precision-time/