[ntp:questions] Re: ntp & adsl

Folkert van Heusden folkert at vanheusden.com
Tue Jan 31 16:44:55 UTC 2006

> >  GENERIC(0)      .DCFa.           0 l   23   64    3    0.000  -17.386  26.356  <- dcf77 receiver
> > +auth1.xs4all.nl    2 u  973 1024  377    8.421    1.179   0.024  <- ntp server of my ISP
> The maximum theoretical contribution from ADSL here is half of 8.421ms, and
> in practice will be rather less.  I'd say that assymmetric loading of the
> line causes much more problems than assymmetric speeds.  In fact the natural
> assymmetric loading tends to act in the opposite direction from the speed
> here.  

assymmetric load? You mean bandwidth usage? I have a shaper script which
gives ntp-traffic (and ssh) priority above all other.

> In this case, I would say that it was much more likely that the DCF clock
> is reading wrongly, probably because it is not compensating for the group
> delays/rise time in its filters, particularly the post detection filter.

Any way how I can fix this?

Folkert van Heusden

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