On Wed, May 07, 2014 at 07:40:28PM +0000, William Unruh wrote: > On 2014-05-07, mike cook <michael.c...@sfr.fr> wrote: > > Le 7 mai 2014 ? 18:32, William Unruh a ?crit : > >> The short answer is no, ntpd cannot play this game. You are trying to > >> use A to discipline not only B but C as well but on machine B. > > > > My reading is that C is not being disciplined at all, but is to be used a > > reference (though non UTC) for B. > > That is my reading as well. But something must be done to determine > those values of x and y (Ctime= xT+y where T is UTC). Either that can be > done on C using something like chrony (better) or ntpd, or B could run > something to determine x and y for C and use those to help discipline B.
The OP said the frequency offset of C is known, so only y is unknown if I'm reading it right. But he also said that A and C are in the same network, so I'm not sure if the frequency of C can be tranferred to B with better accuracy than the frequency of A and if this idea of using A to estimate offset and using C to estimate frequency can give better results than just simply increasing the rate of polling of A. I think support for frequency only sources wouldn't be very difficult to add to chrony. Add a new selection option to bypass the selection algorithm and just combine its frequency with other sources by estimated skew. This could work with both NTP sources and reference clocks. -- Miroslav Lichvar _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
