[ntp:questions] frequency adjusting only

maxime louvel m.louvel at gmail.com
Wed Apr 23 06:12:05 UTC 2008


Hi,

- my network contains only one switch, and all the node are in the same
room.
Thus I don't think cabling is a problem. I still have to check the latency
of the switch.

- I can't use a GPS or other material. I though I wouldn't need any because
I don't won't a great accuracy with the real time, just between my nodes. I
also think it would have been easier and better to have a common high
precision time source (GPS)... But I can't afford that ;)

Do you have an explanation of the so different performances observed in your
NTP synchronisations ?

- I'm going to look at chrony, which at first glance seems usable in my
case.

- I am already using the -x option, to be certain to avoid any step.

Maxime

On Wed, Apr 23, 2008 at 2:10 AM, Unruh <unruh-spam at physics.ubc.ca> wrote:

> Steve Kostecke <kostecke at ntp.org> writes:
>
> >On 2008-04-22, Unruh <unruh-spam at physics.ubc.ca> wrote:
>
> >> Steve Kostecke <kostecke at ntp.org> writes:
> >>
> >> ??? In my experience, on a Lan ntpd shows an internode offset of about
> >> 5-15 usec, and on the internet (ADSL) an offset of about 200usec.
>
> >Here's an aggregated plot of the node offsets on my LAN over the last 24
> >hours. I see +3/-5 milliseconds, not anything near 5-15 microseconds.
>
> >
> http://support.ntp.org/bin/viewfile/Users/SteveKostecke?rev=1;filename=typical_aggregate_lan_offsets.png
>
> I agree those are pretty bad. HOw are they hooked up? It looks like one of
> the hops is via a telephone modem!
>
> See www.theory.physics/chrony/chrony.html
> Mind you those are running with maxpoll 7 not maxpoll 10 (Its my lan and
> ntp server, and I'll do what I want to.)
>
>
> >--
> >Steve Kostecke <kostecke at ntp.org>
> >NTP Public Services Project - http://support.ntp.org/
>
> _______________________________________________
> questions mailing list
> questions at lists.ntp.org
> https://lists.ntp.org/mailman/listinfo/questions
>



-- 
Maxime Louvel
0044 7964 5555 80
43 Allen road
Whitemore reans
WV60AW Wolverhampton
United Kingdom



More information about the questions mailing list