[ntp:questions] Clock and Network Simulator

Rob nomail at example.com
Thu Jul 1 15:11:07 UTC 2010

Miroslav Lichvar <mlichvar at redhat.com> wrote:
> On Wed, Jun 30, 2010 at 10:00:06PM +0000, David L. Mills wrote:
>> Is there somebody around here that understands feedback control
>> theory? You are doing extreme violence to determine a really simple
>> thing, the discipline loop impulse response. There is a much simpler
>> way.
> It was a demonstration of what clknetsim can do. You may be able
> to predict the result, but I'm not. I think being able to verify a
> theory with simulations is always a good thing.

Mr Mills is of the school that says "the design predicts that the
program behaves like that, and the implementation has not changed
for 10 years, so it must be correct".  While I normally adhere to the
same principles, it happened just a week or two ago that he had to
admit that there was a bug in code that he firmly believed was
correct and that an observed behaviour "could not possibly happen".

So I agree with you that it never hurts to test something that theory
has already proved to be correct.  Maybe the actually released program
does not really implement the mechanism that was designed, without
the programmer knowing it.

More information about the questions mailing list