[Pool] question on behavior read from chart

Chuck chuck at sbbsnet.net
Wed Sep 1 14:38:53 UTC 2010


i previously ran a strat1 server that in the pool chart the 'baseline' always centered 
around 0 like it should.

i made 2 major changes at once. i changed the server hardware to an artigo A1000  pico itx 
kit which works extremely well, and i also changed internet providers from a fractional T1 
to VDSL2 (at&t uverse).

now, my chart "0" reference hovers around -2ms consistantly.

is this something i can/should correct in the ntp time1 "fudge" or is it best left alone?
at a consistant -2ms i wonder if it is even 'critical'.

the chart is here:

http://www.pool.ntp.org/scores/99.27.25.65


below are outputs of ntpq -p and ntptime at the server:


    remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
-nist.netservice .ACTS.           1 u   38   64  377   63.485    6.801   0.279
-rolex.netservic .PPS.            1 u   43   64  377   74.287    0.863   0.322
+rackety.udel.ed .PPS.            1 u   52   64  377   55.846   -0.457   0.155
+time-b.nist.gov .ACTS.           1 u   61   64  377   54.337   -0.217   1.796
*GPS_NMEA(1)     .PPS.            0 l   13   16  377    0.000    0.001   0.002


ntp_gettime() returns code 0 (OK)
  time d028e325.76c16dc8  Wed, Sep  1 2010 10:35:17.463, (.463889932),
  maximum error 3958 us, estimated error 1 us, TAI offset 0
ntp_adjtime() returns code 0 (OK)
  modes 0x0 (),
  offset -0.664 us, frequency -62.326 ppm, interval 256 s,
  maximum error 3958 us, estimated error 1 us,
  status 0x2107 (PLL,PPSFREQ,PPSTIME,PPSSIGNAL,NANO),
  time constant 4, precision 0.001 us, tolerance 496 ppm,
  pps frequency -62.326 ppm, stability 0.006 ppm, jitter 2.100 us,
  intervals 5098, jitter exceeded 1735, stability exceeded 0, errors 2.

the maximum error has gone as low as 490us.







-- 

Chuck


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