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by Dave3of5
1328 days ago
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Worked for a company recently that does test equipment for timing and sync. I was surprised to see that very few systems other than computer (servers and suchlike) use unix timestamps. So GNSS systems have their own representation of time and the protocols that most network equipment uses is called PTP. Now-a-days most are trying to use the white rabbit protocol. I was at a conference on this and there are a lot of crazy applications of these timing and sync technologies. The main is in 5G networks but the high frequency trading companies do all of there trading in FPGAs now to reduce time to make a decision so accurate timing is essential. Even the power companies are need high accuracy time to detect surges in powerlines. I spoke to someone from Switzerland who said they had serious security concerns as the timing fibres are poorly secured and open to easy disruption. It was a very interesting domain to work in even though I only was do the app part of the thing. Didn't pay enough though and I was promised a promotion that never came. |
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It's not so much that (Ethernet?) network equipment uses PTP, but rather to get the accuracies desired (±nanoseconds) there needs to be hardware involved, and that makes baking it into chips necessary. It's an IEEE standard so gets rolled into Ethernet.
Applications for PTP are things like electrical grid and cell network timings. Most day-to-day PC and server applications don't need that much accuracy.
Most office and DC servers generally configure NTP, which gives millisecond (10^-3) or tens/hunderds-microsecond (10^-6) accuracy. Logging onto most switches and routers you'll probably see NTP configured.
To get the most out PTP (10^-9) you need to generally run a specialized-hardware master clock.