[ntp:questions] Looking for a NTP stratum 2 appliance

Miroslav Lichvar mlichvar at redhat.com
Fri May 26 10:16:59 UTC 2017


On Fri, May 26, 2017 at 09:35:14AM +0000, Matthew Huff wrote:
> The OXCO oscillator requirement is for hold-over, but we are looking for less jitter in the system. We could strip down the OS machines and run only NTP and make other system adjustments that would accomplish much of the same, but to dedicated a server just for NTP when an appliance is available seems a waste.

If the stratum-1 servers have stable clocks for hold-over, will OXCO
on stratum-2 server make much of a difference? Also, why not point the
clients directly to the stratum-1 servers?

> FINRA has made new timing requirements that are pushing this. Switching to PTP is ultimately the solution, but the switches in our core data center don't support it, and would be very costly to migrate to.

You might want to consider using NTP with HW timestamping if you have
servers with NICs that support it. In my experience that usually
reduces the jitter down to a sub-microsecond level. Unless the network
is heavily loaded for longer periods of time, it should not be
necessary to use PTP and expensive switches.

-- 
Miroslav Lichvar


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