[ntp:questions] Re: ntpd, boot time, and hot plugging

Brad Knowles brad at stop.mail-abuse.org
Fri Feb 4 01:15:57 UTC 2005

At 2:20 PM -0600 2005-02-03, Kenneth Porter wrote:

>>       If you want to make that delay shorter, I guess you could package
>>  Stratum 1 refclocks with every machine.
>  Given the cheap price of a consumer GPS receiver, this doesn't sound that
>  crazy. How fast can ntpd lock on to the NMEA messages?

	Cheap GPS receivers don't do NMEA.  Those that do NMEA don't give 
you a PPS signal, so they're pretty much useless in this role.  You 
have to look very carefully at GPS devices before you can be sure 
that you've found one that will be able to give you a good time 

	For example, the Motorola Oncore 12 might be a piece of crap, 
while the Motorola Oncore 12+ might be good.  Or the Garmin 18 LCS 
might be good, but all the other Garmin 18 models might be garbage. 
You've got to know what you're looking for.

	Please note that I don't have any specific knowledge of which 
models are good or bad, I just pulled these examples out of the air.

	You need to do your own research to ensure that you've got a GPS 
device that will be useful as input to a proposed Stratum 1 time 

Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.

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