[ntp:questions] NIST vs. pool.ntp.org ?

Magnus Danielson magnus at rubidium.dyndns.org
Thu Mar 28 12:22:15 UTC 2013


On 03/27/2013 10:45 PM, David Woolley wrote:
> Robert Scott wrote:
>> I am confused about the proper usage of pool.ntp.org and NIST.
>> pool.ntp.org seems to be a collection of private sector time servers
>> offered for all to use, but with registration expected for regular
>
> The pool system has no provision for enforcing registration. It wouldn't
> make sense to hand out a random server address if most of them then
> refused to serve you because you hadn't registered.
>
>> users. And NIST has a government run set of time servers. Neither
>> group (NIST or pool.ntp.org) seems to include or referece the other.
>
> I would hope all the pool servers ultimately reference their national
> equivalent of NIST and therefore what becomes, after the fact, UTC.
>
> I think you will find that Navstar (GPS) and WWV times are traceable to
> NIST.

Yes and no.

GPS is traceable to USNO. USNO and NIST have traceability between each 
other within the BIPM framework.

> MSF times are traceable to NPL.

NPL is traceable to both USNO and NIST within the BIPM framework.

>> Are they in competition? Who normally uses the NIST servers and who
>> uses pool.ntp.org?
>
> The open NIST servers are heavily overloaded, so probably don't serve
> the highest quality time, but they are likely to be around for a long time.

I would setup a local server under your control. It will help both from 
debugging and noise perspective.

Cheers,
Magnus


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