[ntp:questions] Solving the right problem

unruh unruh at wormhole.physics.ubc.ca
Thu Mar 25 20:54:15 UTC 2010

On 2010-03-25, E-Mail Sent to this address will be added to the BlackLists <Null at BlackList.Anitech-Systems.invalid> wrote:
> unruh wrote:
>>> You said:  "In most cases, it is easier to solve the
>>>  problem of sync'ing all computers to a correct timesource
>>>  (and thus all be mutually in sync)...".
>>> I think I agree with that principal, though I don't yet
>>>  feel I know enough to 'do it'.  Would like to have your
>>>  (and others') help in learning the nuts-and-bolts of
>>>  understanding that, and how to accomplish it.
>> It means that you have one ( or two ) computers sync to
>>  an external source and then use that machine as the
>>  source for the others.
> It doesn't have to be an "external source", if cheap is
>  not a goal, and isolation from the rest of the world is.
>  They can get their own in-house frequency standard(s),
>   to PPS discipline their NTP server(s).
> I'm certain the sales people at Symmetricom could provide
>  them with NTP servers that don't make use of any outside
>  world references.

Sure, for a few tens or hundreds of thousands of dollars. When a gps
puck is $100, plus some wire. I would suspect that they would be more
willing to spend $200 for a p\gps puck and some wire, than $100000 for a
H Maser clock, but who knows, maybe not. On the other hand all he wanted
was to sync the computers to each other, and learning about orphan mode
should only cost a few $100 in his time and salary as well.

> <symmetricom.com/products/ntp-servers/modular-ntp-solutions/>
>  symmetricom.com sells Cesium, Rubidium and Hydrogen Maser Standards
>  quartzlock.com sells Rubidium Standards
>     (and used to sell Hydrogen Maser Standards?)
>  novatech-instr.com sells Rubidium Standards
>  Selecting a Primary Frequency Standard for a Calibration Laboratory
>   (Cal Lab Int. Jour. of Metrology, April 2008, pp. 33-39)
>    <tf.nist.gov/general/pdf/2289.pdf>

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