[ntp:questions] Re: Improving ACTS performance

Joshua Coombs jcoombs at gwi.net
Thu Apr 6 19:40:42 UTC 2006

> I've seen ACTS referred to as "Automated Containerized Trash 
> Service".
> What you see may be the best that ACTS can do.
> Have you considered using another technology?  A GPS receiver is not 
> terribly expensive (as low as $85 US) and such a receiver designed 
> for timing applications can deliver accuracy in the neighborhood of 
> 1 microsecond.  The PPS signal is accurate to better than 100 
> nanoseconds but few computers are capable of that degree of 
> accuracy.  1 microsecond is easily obtainable.  I use a Sun Ultra 10 
> (440MHz processor), Solaris 8 and ntpd 4.0 and get that accuracy. 
> That's eight year old technology; more modern hardware and software 
> might do better.

Just getting permission to use a phoneline for ACTS required small 
sacrifices I may never recover from...

I'd love to setup GPS or Cellular driven time clocks, but my two data 
sites are setup such that I can't get a viable signal inside, and have 
no access to setup an antenna outside.

I 'think' I may have spotted part of the trouble.  My init/dial string 
wasn't disabling error correction or compression.  I'd imagine one or 
both could really wreck havoc with the latency estimation.  Now I get 
to wait a week to see if I'm right... : )

Joshua Coombs 

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