[ntp:questions] Driver Help?
Richard B. Gilbert
rgilbert88 at comcast.net
Tue Jun 12 23:38:38 UTC 2007
Karl Denninger wrote:
> I'm hacking a copy of the NMEA driver to work with the CDMA modems
> (which provide a clock signal even if not subscribed - kinda
> interesting) and have it talking to the device.
> But - even though the dispersion looks reasonable and so does jitter,
> the application refuses to consider it "synced".
> I have the following.....
> ntpdc> sysi
> system peer: CDMA(0)
> system peer mode: client
> leap indicator: 11
> stratum: 16
> precision: -19
> root distance: 0.00000 s
> root dispersion: 0.00165 s
> reference ID: [126.96.36.199]
> reference time: 00000000.00000000 Thu, Feb 7 2036 0:28:16.000
> system flags: auth monitor ntp kernel stats
> jitter: 0.001129 s
> stability: 0.000 ppm
> broadcastdelay: 0.003998 s
> authdelay: 0.000000 s
> ntpdc> peer
> remote local st poll reach delay offset disp
> *CDMA(0) 127.0.0.1 0 16 377 0.00000 0.241065 0.00697
> Obviously, I'm missing SOMETHING....... the dispersion looks reasonable,
> but it will not lock up on the clock. Any idea where I start?
I think you may be missing the "*" in column one above. That indicates
that ntpd has your CDMA(0) clock as the synchronization source.
The offset looks a little high unless ntdp was started quite recently.
Bear in mind that ntpd needs time to beat your clock into submission.
Thirty minutes is a good length of time to wait before taking offset and
dispersion figures seriously.
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