[time-nuts] Noob question, NTP stratum 1.

[shouldbe q931]

On Mon, Jul 22, 2019 at 5:03 PM wildylion via time-nuts <
time-nuts at lists.febo.com> wrote:

> Yeah, of course I will NOT do anything home-grown for the datacenter.
>
> But currently it uses 3 Stratum 2 NTP servers, one per DC, with them
> referencing a list of 4 close-by Stratum 1 sources.
>
> ntpstat generally says that time is correct within ~50 ms, while jitter
> and offset generally don't exceed 1ms, the root dispersion is quite large.
> Also these Stratum 2 NTPs are run from Cisco routers, which I doubt are
> very good at timekeeping.
>
> When I implemented this scheme, I offered to have S2 on a set of x86
> servers, but was overruled by management who said it'll be better if we run
> S2's off Cisco gear.
>
While one can run most Cisco routers as NTP servers, I would advise against
doing this as they don't have very good clocks, and it adds to the
management plane load.


> So what if we add a couple GPSDO's into the mix, using them as primary
> time sources alongside public Stratum1 NTP servers for sanity check? And of
> course moving the S2's to something more stable.
>
Moving away from the Cisco routers would be my first step.


> My own, homegrown S1 pool NTP is another matter entirely - I think just a
> tuned Raspi with a M8N will be enough?
>
A Pi with a ublox is great fun, unfortunately the clock on the Pi is
"poor", and this is a limiting factor.
https://www.ntpsec.org/white-papers/stratum-1-microserver-howto/

Cheers

Arne