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

[Steven Sommars]

US operators are planning to shut down their CDMA networks.  See for example
https://www.fiercewireless.com/wireless/verizon-to-shut-down-2g-cdma-1x-network-by-end-2019

I wouldn't be surprised to see this date get pushed back though.



On Mon, Jul 22, 2019 at 8:05 PM K5ROE Mike <K5ROE at roetto.org> wrote:

> You may want to look at something an Endrun CDMA ntpserver for the
> datacenter; don't need view of the sky. Available on the used market sub
> $1k
>
> Standard solution for this scenario.
>
>
> K5ROE Mike
>
> On 7/22/19 10:50 AM, wildylion via time-nuts 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.
> >
> > 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.
> >
> > My own, homegrown S1 pool NTP is another matter entirely - I think just
> a tuned Raspi with a M8N will be enough?
> >
> > Sent with [ProtonMail](https://protonmail.com) Secure Email.
> >
> > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > On Monday, 22 July 2019 г., 17:38, Taka Kamiya <tkamiya9 at yahoo.com>
> wrote:
> >
> >> If you have 100 production servers with database, I am going to
> strongly discourage you from taking a "home grown" route.  You will need
> multiple redundant implementation with fail-over.  You mentioned budget.
> How much are your bosses willing to pay for consultation fees for failed or
> corrupted data?  I am assuming you are talking about Oracle RDBMS with
> minimum of 2 way RAC.
> >>
> >> If you are using collocation services, doesn't the center itself offer
> ntp service for fee?
> >>
> >> If you need 24 hour hold-over, I will take nothing less than multiple
> ovenized crystal OSC GPSDO with redundancy per center.  Then feed that into
> ntp server with multi-location fail over.
> >>
> >> If I were responsible for managing such system and if my boss will want
> me to go cheap route, I will seriously fight it.  If it's successful, your
> boss will get credit for spending little and getting a big benefit.  WHEN
> it fails, it's going to be your fault for not mitigating risk
> sufficiently.  Try pricing out 2 days of consulting fees....
> >>
> >> ---------------------------------------
> >> (Mr.) Taka Kamiya
> >> KB4EMF / ex JF2DKG
> >>
> >> On Monday, July 22, 2019, 10:05:56 AM EDT, wildylion via time-nuts <
> time-nuts at lists.febo.com> wrote:
> >>
> >> Hello there,
> >>
> >> I wanted to ask for advice regarding NTP
> >>
> >> Situation 1:
> >> What I currently have is a uBlox M8N GPS puck I'm planning to use with
> the Raspberry PI. Seems like it should work almost out of the box with some
> kernel tuning, but I have a question about short term stability in the
> event of GPS loss - how well will the board hold over if it's lost GPS for,
> say, 24 hours?
> >>
> >> Situation 2:
> >> Also, there's a need for more dependable NTP time sources for our
> colocated spaces.
> >>
> >> What we have is about 100 servers, some of them running DBMS that
> wouldn't like clock drift at all. After a recent incident involving NTP
> I've got an idea to install GPSDO time servers in each datacenter and slave
> them to stratum2's that will be actually distributing time to clients.
> >>
> >> All the certified GNSS disciplined clocks are really expensive (way
> more than the management would approve), so what I'm planning to do is
> possibly getting a couple LeoNTP units and using them as the root time
> sources, would this be a good plan? Of course, all the NTP infrastructure
> will be monitored, and possibly we'll use Stratum 2 servers which would be
> slaved to GPSDO S1's AND the public NTP pool for sanity checks.
> >>
> >> Maybe BG7TBL's units instead of LeoNTP?
> >> Is that a good idea?
> >>
> >> Sent with [ProtonMail](https://protonmail.com) Secure Email.
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