Recommendation on NTP appliances/devices

Saku Ytti saku at ytti.fi
Fri Apr 4 10:48:52 UTC 2014


On (2014-04-04 20:37 +1100), Julien Goodwin wrote:

> > Meinberg[0] pegs rubidium at ±8ms per year, if you need NTP to do say single
> > direction backbone SLA measurement you want to have microsecond precision.
> 
> Those two statements don't go together.

Point I was making is that free-running rubidium is not accurate enough for
QoS measurements of IP core.

> Also outside the HFTers most of us don't care about a few milliseconds
> (sure an extra 50ms can be a pain, but is trivial to measure).

Jitter in backbone is low tens of microseconds, if you want to measure how
that changes over time, free-running rubidium is not going to cut it.

-- 
  ++ytti




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