[ntp:questions] Driver Help?

Karl Denninger karl at denninger.net
Wed Jun 13 03:56:08 UTC 2007

Karl Denninger wrote:
> Jason Rabel wrote:
>> What OS are you running, and what CDMA modem are you using? (Just 
>> curious)
>> Also from the info you gave it looks like it is using your CDMA 
>> source, but
>> seeing the stratum at 16 I don't think you have had NTP run long 
>> enough to
>> adjust the clock into sync.
>> Jason 
> FreeBSD 6 (and 7; I have both here); the modem is a Multitech MTCBA.

Quick update on this.... it appears that while the timecode is being 
stuffed appropriately, the underlying NTPD daemon doesn't like it - 
after a half-hour or so (running with debug turned up) and watching it 
log things, it fails to lock on and resets the time source, dropping and 
restarting the clock.

I assume this means it is unable to get "happy enough" with the 
stability of the timestamps to formulate a "solution", declares the 
clock "broken", and then restarts....... yes?

The obvious question is "can a time source that outputs only with 1 
second resolution and only when polled generate 
sufficiently-high-quality reference time for the system to use it?"

If the answer is "no", then the curtain needs to be drawn on this 
attempt.  If the answer is "yes", then I need to figure out how to 
accomplish getting better input resolution I suspect - perhaps with a 
helper application that polls at a higher rate of speed (e.g. several 
times per second) and "stuffs" timecode events into the receive buffer 
(e.g. via a named pipe or similar)

Karl Denninger (karl at denninger.net)

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