[ntp:questions] Re: Make NTP timestamps leap-second-neutral (like GPS time)

Michel Hack hack at watson.ibm.com
Tue Jan 13 23:30:10 UTC 2004


hack at watson.ibm.com (hack) wrote in message news:<btht5j$bbm$2 at news.btv.ibm.com>...
> In article <bthstv$bbm$1 at news.btv.ibm.com>, hack <hack at watson.ibm.com> wrote:
> 
> So, here's a simple question:  Was there an NTP jiggle problem after the
> last LSE in July 1999, and is there likely to be one at the next LSE --
> or have the algorithms already improved to the point that the pinball
> effects described so vividly in 1994 have vanished?

I used google search for "leap second ntp" for a 1-month period around each
of the last 4 leap seconds.  There were a couple of items about GPS receivers
not handling the event promptly and some jumpy NTP reactions to such failures;
there was also a report about NTP v4 misbehaving (when NTP v3 handled events
apparently well) -- but nothing like the pinball effect described for 1994 and
its implication that this was "a tradition going back many years".

Does this mean that the last 3 leap second events were (in the absence of
misbehaving hardware) perfectly smooth from NTP's point of view?  And has
NTP version 4 been fixed in this respect (if indeed it was broken)?

Michel.



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