[ntp:questions] Performance?
dhavey
dhavey at gmail.com
Mon Dec 22 22:15:16 UTC 2008
On Dec 22, 1:52 pm, dhavey <dha... at gmail.com> wrote:
> On Dec 22, 1:25 pm, Unruh <unruh-s... at physics.ubc.ca> wrote:
>
>
>
> > It is because you are using the nmea from them, not the PPS input and NMEA
> > takes a few msec to go from the GPS to your computer ( 60 characters at
> > 9600BD ).
>
> > dhavey <dha... at gmail.com> writes:
> > >This is the ntpq -p output from 2 machines connected to Garmin GPS's.
> > >The machines ip's of the 2 machines are 192.168.0.28 and .29. They
> > >are about a millisecond apart! That's no better than the server
> > >without the GPS. What did I do to deserve such lousy performance.?
> > >server 127.127.20.0 prefer minpoll 4
> > >fudge 127.127.20.0 refid GPS flag3 1 flag2 0 time1 0.0
> > > and the machines are peered together.
> > > remote refid st t when poll reach delay
> > >offset jitter
> > >==============================================================================
> > >*192.168.0.2 69.25.96.13 2 u 83 1024 377 0.898
> > >-0.201 0.456
> > > 192.168.0.26 192.168.0.2 3 u 171 1024 376 1.588
> > >-1.921 0.416
> > > 192.168.0.27 192.168.0.2 3 u 204 1024 376 1.206
> > >2.312 0.008
> > > 192.168.0.29 192.168.0.28 4 u 323 256 166 0.110
> > >0.908 0.299
> > > GPS_NMEA(0) .GPS. 0 l - 16 0 0.000
> > >0.000 0.001
> > > remote refid st t when poll reach delay
> > >offset jitter
> > >==============================================================================
> > >+192.168.0.26 192.168.0.2 3 u 67 512 177 0.100
> > >-2.753 0.374
> > >+192.168.0.27 192.168.0.2 3 u 67 512 377 0.055
> > >2.018 0.314
> > >*192.168.0.28 192.168.0.2 3 u 120 512 137 0.020
> > >-0.953 0.337
> > > GPS_NMEA(0) .GPS. 0 l - 16 0 0.000
> > >0.000 0.001
>
> According to ./ppstest the GPS works until I start ntpd.
Okay the ppstest is asserting and clearing but still no ntpq -p reach:
remote refid st t when poll reach delay
offset jitter
==============================================================================
*192.168.0.2 69.25.96.13 2 u 12 64 77 0.141
1.222 0.564
192.168.0.26 192.168.0.2 3 u 42 64 76 0.001
-0.109 0.506
192.168.0.27 192.168.0.2 3 u 1 64 77 0.083
5.219 0.516
+192.168.0.29 192.168.0.26 4 u 15 64 76 0.001
0.478 1.144
GPS_NMEA(0) .GPS. 0 l - 16 0 0.000
0.000 0.001
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