On Thu, Dec 1, 2016, at 09:01 AM, Chris Albertson wrote: > The other thing you might look at is NOT using NTP but using PTP. This > might be a better match to your needs but it requires that you replace > all your network gear with equipment that can make hardware time stamps > on the network packets.
You don't actually need to have PTP-capable network gear to make PTP work reasonably well. I have a small test environment with a Symmetricom S300-Rb PTP grandmaster distributing time to six Cisco UCS blades running FreeBSD. The S300 does hardware timestamping, but the UCS blades do not. The network has a Cisco UCS fabric switch plus an Arista 7124S, neither of which support PTP transparency. Works fine; I haven't measured it exhaustively, but preliminary data suggests that I am getting 2.5e-5 seconds of drift in the worst case. I've heard reports that full hardware timestamping and transparent switching can easily get you into the 1e-7 range, but I haven't tried that yet. /gp _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
