[ntp:questions] NTP.ORG MEINBERG KEEP TIME ACCURATE to 10MS
david-taylor at blueyonder.co.uk.invalid
Thu Nov 15 06:54:20 UTC 2012
On 14/11/2012 21:40, gbusenberg at yahoo.com wrote:
> Below ntpq -p from my 10.1.126.202 server which gets time from 10.1.126.204. I see there is a lot of Jitter. Is the offset of 259ms.
> remote refid st t when poll reach delay offset jitter
> *10.1.126.204 18.104.22.168 3 u 1006 1024 77 0.043 -259.69 165.850
> driftfile "C:\Program Files (x86)\NTP\etc\ntp.drift"
> server 10.1.126.204 iburst minpoll 4
In which case, there must be something grossly wrong. The jitter I see
with LAN servers to LAN clients is usually well under a millisecond, and
on Windows Vista 0.977 milliseconds. Even WAN servers only show 2 - 10
milliseconds (typically the low end of that range). Offsets are in the
order of 0.5 milliseconds for LAN servers, and less than 10 milliseconds
for WAN servers.
So for a LAN connection to show 259 milliseconds offset and 165
milliseconds of jitter suggests a problem. Perhaps 10.1.126.204 is
really not very stable at all? Perhaps, as was suggested, you are tying
too closely to the off-site server? Perhaps the LAN is saturated? I do
suggest that you consider a GPS/PPS for one of your local servers (or
even the PC if one is on 24 x 7 and has a serial port). You could even
use a box as simple as the Raspberry Pi computer coupled with a GPS with
the total solution coming to around US $100 and providing within 50
Stick it somewhere on your LAN where there is a view through a window!
More information about the questions