[ntp:questions] Peer Review of ntpq -c rv

Ron Frazier (NTP) timekeepingntplist at c3energy.com
Thu Mar 8 03:17:51 UTC 2012


On 3/7/2012 11:59 AM, David Lord wrote:
> Alby VA wrote:
>> On Mar 7, 10:59 am, David Lord <sn... at lordynet.org> wrote:
>>> Alby VA wrote:
>>>>  I'm looking to get a little feedback on if the following output of my
>>>> Sure GPS / FreeBSD
>>>> setup looks like its running smoothly and keeping time correctly.
>>>> assID=0 status=0115 leap_none, sync_atomic, 1 event,
>>>> event_clock_reset,
>>>> version="ntpd 4.2.... at 1.2349-o Mon Feb 20 22:00:33 UTC 2012 (1)",
>>>> processor="amd64", system="FreeBSD/9.0-RELEASE", leap=00, stratum=1,
>>>> precision=-19, rootdelay=0.000, rootdisp=0.269, refid=PPS,
>>>> reftime=d301d22f.dc1393c2  Wed, Mar  7 2012  7:25:19.859,
>>>> clock=d301d230.cc08bad9  Wed, Mar  7 2012  7:25:20.797, peer=41909,
>>>> tc=4, mintc=3, offset=-0.034, frequency=-25.214, sys_jitter=0.002,
>>>> clk_jitter=0.002, clk_wander=0.001
>>>>  Here are my website graphs/stats I've been keeping since day 1.
>>>> NTP Clock Offset:http://godzilla.empire.org:9999/
>>>> NTP Offset from 
>>>> UTC:http://godzilla.empire.org:9999/godzilla_ntp-b.html
>>> Could you also post output from ntpq -p
>>>
>>> I don't have a pc with recent FreeBSD but the desktop
>>> I updated to NetBSD-6 only 2 hours ago gives:
>>>
>>> remote                refid        st t poll reach delay offset jitter
>>> +ntp1.lordynet.org    81.187.61.74  2 u  512   377 0.450 -4.961  3.024
>>> *ntp0.lordynet.org.uk .MSFa.        1 u  512   377 0.642 -0.828  4.785
>>> +<local pc>           .PPSb.        1 u  512   377 1.572 -1.935  3.187
>>> -<local pc2>          81.187.61.74  2 u  512   377 1.553 -6.075  3.892
>>>
>>> Does the Sure have a PPS output you can use?
>>>
>>> <Local pc> is using a Sure with PPS
>>> # ntpq -c rv -p me6000
>>> associd=0 status=0119 leap_none, sync_pps, 1 event, leap_armed,
>>> version="ntpd 4.2.6p5....",
>>> processor="i386", system="NetBSD/5.1_STABLE",
>>> .....
>>> offset=-0.001 sys_jitter=0.004
>>>
>>> David
>>
>>
>>
>>
>> Here is my ntpq -p  output:
>>
>>
>> [alby at godzilla.empire.org(tcsh):6] ntpq -p
>>      remote           refid      st t when poll reach   delay
>> offset  jitter
>> ============================================================================== 
>>
>> -ntp.alaska.edu  .GPS.            1 u  133  128  377  120.428
>> -2.464   0.371
>> +utcnist2.colora .ACTS.           1 u   53  128  377   66.362
>> -4.215   0.429
>> -time-a.nist.gov .ACTS.           1 u  670  128  240   16.473
>> 2.627  17.066
>> +tick.usask.ca   .GPS.            1 u  110  128  377  104.848
>> -3.473   1.482
>> -cronos.cenam.mx .GPS.            1 u   49  128  377  100.163
>> 10.784  27.096
>> oPPS(0)          .PPS.            0 l    6   16  377    0.000
>> -0.018   0.002
>> *GPS_NMEA(0)     .GPSb.           0 l    9   16  377    0.000
>> -36.164  18.050
>> [alby at godzilla.empire.org(tcsh):7]
>>
>
> Sorry I misread your message and had in my mind that you
> were getting msec offsets rather than usec. I canceled my
> reply after posting.
>
> The offsets still look to be high for what can be achieved
> from pps but are not reflected in the jitter.
>
>
> David
>


Correct me if I'm wrong, but, doesn't that last line mean 36 ms of 
offset with 18 ms of jitter?

Ron


-- 

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Ron Frazier
timekeepingdude AT c3energy.com



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