4 ms·
I'm curious, what kind of use case do you have that requires nanosecond-precision timestamping for UDP packets? All I can think of are stratum 1 NTP servers, bu
by 10000truths 6y ago
I'm curious, what kind of use case do you have that requires nanosecond-precision timestamping for UDP packets? All I can think of are stratum 1 NTP servers, but that doesn't seem to fit the rest of your description.
- Matthias247 6y agoThe use-cases that I'm aware of for precise timestamping on UDP packets are realtime audio/video transmission (ethernet AVB) and static resource allocation on ethernet channels in order to have deterministic delivery delivery guarantees. The latter is interesting for other industrial and automotive bus systems, which want to use ethernet as a replacement for older bus system like CAN. I'm not sure what level of timestamp precision is required for those. The solutions also likely don't require 10Gbit/s.
- knaq 6y agoIt sounds like stock trading. People have been known to process packets in an FPGA to win at that game.
- ncmncm 6y agoTrillions of dollars are traded every day via custom FPGAs. Arguably, it amounts to automated stealing, but is 100% legal. All the NICs have FPGAs on them nowadays, to do regular IP-related stuff, so it is just a matter of reprogramming them.
- ncmncm 6y agoHonestly, the customers don't need nanosecond accuracy, but the NICs offer it, and the nanoseconds in a second fits neatly in 32 bits. In practice, microseconds is better than enough, and all you get from PTP anyway.