[time-nuts] Basic Stratum 1 question

John Ackermann N8UR jra at febo.com
Thu Aug 2 11:56:51 EDT 2007

Jared Morrisen wrote:
> ); SAEximRunCond expanded to false
> Errors-To: time-nuts-bounces+jra=fluffles.febo.com at febo.com RETRY
> Hi,
> I am having a debate with our CIO.  He wrote in a memo about timing:
> *Local hardware is to be considered Stratum 1, since it get time from its
> own CMOS.*
> I told him that absurd and that it can't be considered stratum 1.

Hi Jared --

I don't want to get in the middle of that argument!

However, note that there are two different definitions of "Stratum 1" 
floating around.

In the NTP sense, it is nearness to a reference clock that 
(theoretically) provides time traceable to a national institute.  So an 
NTP "stratum 1" server is one that is directly connected to a reference 
clock.  (Check the NTP website; I'm sure you'll be able to find a more 
formal version of that definition somewhere there.)

But in the telecom industry, "Stratum 1" signifies a certain level of 
timing performance, and I suppose that some computer system somewhere in 
the world might be able to meet that standard for some period of time. 
Someone else will be able to tell you just what the definition of 
Stratum 1 is.

So the real question is which of those definitions is your CIO using? 
Based on that, you should be able to answer that either (a) local CMOS 
isn't a reference clock traceable to a national institute, or (b) that 
the CMOS clock isn't certified to meet telecom Stratus 1 standards.

Of course, if his point is that one local free-running clock is the 
"master" and that he cares only about synchronization, not accuracy, 
across the network, then he might be making sense.  But he's not using 
the terminology correctly.


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