NTPsec

A-ntpsec-7-day-stats

Report generated: Wed Aug 17 19:17:05 2022 UTC
Start Time: Wed Aug 10 19:16:56 2022 UTC
End Time: Wed Aug 17 19:16:56 2022 UTC
Report published: Wed Aug 17 12:17:55 2022 PDT
Report Period: 7.0 days

Local Clock Time/Frequency Offsets

local offset plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Time Offset -73.873 -3.126 -1.215 0.045 1.190 2.144 159.938 2.405 5.270 1.267 0.001 µs 18.96 3129
Local Clock Frequency Offset -448.822 -202.713 -130.997 -20.447 10.590 15.076 1,134.003 141.587 217.789 49.367 -35.684 ppb -10.97 67.68

The time and frequency offsets between the ntpd calculated time and the local system clock. Showing frequency offset (red, in parts per million, scale on right) and the time offset (blue, in μs, scale on left). Quick changes in time offset will lead to larger frequency offsets.

These are fields 3 (time) and 4 (frequency) from the loopstats log file.



Local RMS Time Jitter

local jitter plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Time Jitter 0.218 0.374 0.454 0.790 2.222 4.390 56.019 1.768 4.016 0.998 1.043 µs 14.28 433.9

The RMS Jitter of the local clock offset. In other words, how fast the local clock offset is changing.

Lower is better. An ideal system would be a horizontal line at 0μs.

RMS jitter is field 5 in the loopstats log file.



Local RMS Frequency Jitter

local stability plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local RMS Frequency Jitter 0.000 0.080 0.105 1.177 3.451 6.978 158.120 3.346 6.898 1.935 1.521 ppb 28.33 1699

The RMS Frequency Jitter (aka wander) of the local clock's frequency. In other words, how fast the local clock changes frequency.

Lower is better. An ideal clock would be a horizontal line at 0ppm.

RMS Frequency Jitter is field 6 in the loopstats log file.



Local Clock Time Offset Histogram

local offset histogram plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Offset -73.873 -3.126 -1.215 0.045 1.190 2.144 159.938 2.405 5.270 1.267 0.001 µs 18.96 3129

The clock offsets of the local clock as a histogram.

The Local Clock Offset is field 3 from the loopstats log file.



Local Temperatures

local temps plot

Local temperatures. These will be site-specific depending upon what temperature sensors you collect data from. Temperature changes affect the local clock crystal frequency and stability. The math of how temperature changes frequency is complex, and also depends on crystal aging. So there is no easy way to correct for it in software. This is the single most important component of frequency drift.

The Local Temperatures are from field 3 from the tempstats log file.



Local Frequency/Temp

local freq temps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -448.822 -202.713 -130.997 -20.447 10.590 15.076 1,134.003 141.587 217.789 49.367 -35.684 ppb -10.97 67.68
Temp ZONE0 49.926 50.464 51.540 53.692 59.072 60.148 64.990 7.532 9.684 2.390 54.616 °C

The frequency offsets and temperatures. Showing frequency offset (red, in parts per million, scale on right) and the temperatures.

These are field 4 (frequency) from the loopstats log file, and field 3 from the tempstats log file.



Local GPS

local gps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
nSats 6.000 7.000 8.000 10.000 11.000 12.000 12.000 3.000 5.000 1.020 9.569 nSat 613.3 5354
TDOP 0.500 0.540 0.590 0.810 1.270 1.530 2.100 0.680 0.990 0.215 0.858 37.26 156.3

Local GPS. The Time Dilution of Precision (TDOP) is plotted in blue. The number of visible satellites (nSat) is plotted in red.

TDOP is field 3, and nSats is field 4, from the gpsd log file. The gpsd log file is created by the ntploggps program.

TDOP is a dimensionless error factor. Smaller numbers are better. TDOP ranges from 1 (ideal), 2 to 5 (good), to greater than 20 (poor). Some GNSS receivers report TDOP less than one which is theoretically impossible.



Server Offsets

peer offsets plot

The offset of all refclocks and servers. This can be useful to see if offset changes are happening in a single clock or all clocks together.

Clock Offset is field 5 in the peerstats log file.



Server Offset 104.131.155.175

peer offset 104.131.155.175 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 104.131.155.175 0.373 1.970 2.467 3.297 4.107 4.566 5.914 1.639 2.596 0.536 3.308 ms 153.4 876.3

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 162.159.200.1

peer offset 162.159.200.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 162.159.200.1 -8.479 1.341 2.404 3.180 3.916 4.409 39.694 1.512 3.068 1.005 3.173 ms 39.92 1144

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 169.229.128.134

peer offset 169.229.128.134 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 169.229.128.134 -41.299 1.473 1.942 2.395 2.932 3.578 15.543 0.991 2.105 1.100 2.397 ms -23.83 1089

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 173.11.101.155

peer offset 173.11.101.155 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 173.11.101.155 -16.511 -2.812 -1.806 -0.289 0.756 1.757 4.625 2.562 4.569 0.885 -0.372 ms -10.29 92.93

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 178.62.68.79

peer offset 178.62.68.79 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 178.62.68.79 -18.789 -6.419 -2.771 1.342 3.085 7.968 10.492 5.856 14.386 2.453 1.071 ms -4.09 27.31

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 192.168.1.11

peer offset 192.168.1.11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.11 -2.118 -0.376 -0.192 0.072 0.442 0.693 47.922 0.634 1.069 0.609 0.105 ms 55.72 3994

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 204.17.205.23

peer offset 204.17.205.23 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.23 -5.925 0.416 0.896 1.889 2.820 3.432 5.554 1.924 3.016 0.642 1.881 ms 11.94 45.71

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 216.218.192.202

peer offset 216.218.192.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 216.218.192.202 -1.673 0.496 1.457 2.377 3.043 3.868 6.756 1.586 3.372 0.581 2.345 ms 35.98 142.1

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 216.218.254.202

peer offset 216.218.254.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 216.218.254.202 -11.504 -0.810 1.498 2.367 3.014 3.721 20.637 1.516 4.531 0.913 2.327 ms 11.75 235.5

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 45.33.37.82

peer offset 45.33.37.82 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 45.33.37.82 -5.550 1.646 1.979 2.670 3.424 4.162 6.090 1.444 2.517 0.517 2.673 ms 83.75 422.6

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 66.220.9.122

peer offset 66.220.9.122 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 66.220.9.122 -0.349 1.174 2.004 2.495 2.927 3.866 5.102 0.923 2.692 0.420 2.495 ms 134.3 743.3

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset SHM(0)

peer offset SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(0) -0.088 -0.055 -0.054 -0.049 -0.045 -0.043 14.901 0.009 0.012 0.074 -0.049 s 184.7 3.66e+04

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset SHM(1)

peer offset SHM(1) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(1) -0.000 -0.000 -0.000 0.000 0.000 0.000 66.076 0.000 0.000 0.178 0.001 s 303.1 1.076e+05

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Jitters

peer jitters plot

The RMS Jitter of all refclocks and servers. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 104.131.155.175

peer jitter 104.131.155.175 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 104.131.155.175 0.000 0.000 0.480 1.577 13.078 50.963 78.162 12.598 50.963 8.684 3.847 ms 3.851 29.91

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 162.159.200.1

peer jitter 162.159.200.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 162.159.200.1 0.000 0.332 0.614 1.917 12.786 28.814 104.959 12.171 28.482 6.950 3.882 ms 6.024 70.69

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 169.229.128.134

peer jitter 169.229.128.134 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 169.229.128.134 0.000 0.308 0.533 1.682 10.574 26.321 75.362 10.040 26.013 5.206 3.224 ms 4.485 41.37

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 173.11.101.155

peer jitter 173.11.101.155 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 173.11.101.155 0.000 0.590 1.076 2.309 14.045 36.738 238.639 12.969 36.148 10.632 4.589 ms 11.3 220.7

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 178.62.68.79

peer jitter 178.62.68.79 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 178.62.68.79 0.000 0.000 0.677 2.687 17.574 44.976 104.534 16.897 44.976 8.883 5.184 ms 5.503 57.01

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 192.168.1.11

peer jitter 192.168.1.11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.11 0.000 0.233 0.367 1.129 10.675 28.175 231.662 10.308 27.942 8.399 2.990 ms 10.26 190.6

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 204.17.205.23

peer jitter 204.17.205.23 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.23 0.000 0.309 0.705 1.962 13.991 49.385 166.640 13.286 49.075 9.713 4.376 ms 7.669 106.7

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 216.218.192.202

peer jitter 216.218.192.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 216.218.192.202 0.000 0.298 0.629 1.828 12.455 39.270 100.188 11.826 38.972 7.203 3.727 ms 5.305 52.05

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 216.218.254.202

peer jitter 216.218.254.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 216.218.254.202 0.000 0.000 0.480 1.758 12.647 27.332 75.408 12.167 27.332 5.560 3.383 ms 4.33 39.77

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 45.33.37.82

peer jitter 45.33.37.82 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 45.33.37.82 0.000 0.145 0.583 1.798 10.740 37.973 283.255 10.157 37.828 13.039 4.014 ms 13.5 277.1

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 66.220.9.122

peer jitter 66.220.9.122 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 66.220.9.122 0.000 0.000 0.382 1.531 13.484 21.196 21.314 13.101 21.196 4.253 2.985 ms 2.122 9.06

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter SHM(0)

peer jitter SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(0) 0.000 0.000 0.000 0.001 0.002 0.003 14.951 0.002 0.003 0.119 0.003 s 83.9 8201

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter SHM(1)

peer jitter SHM(1) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(1) 0.000 0.245 0.339 0.747 2.529 5.290 99.051 2.190 5.045 1.282 1.037 µs 21.29 1149

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -448.822 -202.713 -130.997 -20.447 10.590 15.076 1,134.003 141.587 217.789 49.367 -35.684 ppb -10.97 67.68
Local Clock Time Offset -73.873 -3.126 -1.215 0.045 1.190 2.144 159.938 2.405 5.270 1.267 0.001 µs 18.96 3129
Local RMS Frequency Jitter 0.000 0.080 0.105 1.177 3.451 6.978 158.120 3.346 6.898 1.935 1.521 ppb 28.33 1699
Local RMS Time Jitter 0.218 0.374 0.454 0.790 2.222 4.390 56.019 1.768 4.016 0.998 1.043 µs 14.28 433.9
Server Jitter 104.131.155.175 0.000 0.000 0.480 1.577 13.078 50.963 78.162 12.598 50.963 8.684 3.847 ms 3.851 29.91
Server Jitter 162.159.200.1 0.000 0.332 0.614 1.917 12.786 28.814 104.959 12.171 28.482 6.950 3.882 ms 6.024 70.69
Server Jitter 169.229.128.134 0.000 0.308 0.533 1.682 10.574 26.321 75.362 10.040 26.013 5.206 3.224 ms 4.485 41.37
Server Jitter 173.11.101.155 0.000 0.590 1.076 2.309 14.045 36.738 238.639 12.969 36.148 10.632 4.589 ms 11.3 220.7
Server Jitter 178.62.68.79 0.000 0.000 0.677 2.687 17.574 44.976 104.534 16.897 44.976 8.883 5.184 ms 5.503 57.01
Server Jitter 192.168.1.11 0.000 0.233 0.367 1.129 10.675 28.175 231.662 10.308 27.942 8.399 2.990 ms 10.26 190.6
Server Jitter 204.17.205.23 0.000 0.309 0.705 1.962 13.991 49.385 166.640 13.286 49.075 9.713 4.376 ms 7.669 106.7
Server Jitter 216.218.192.202 0.000 0.298 0.629 1.828 12.455 39.270 100.188 11.826 38.972 7.203 3.727 ms 5.305 52.05
Server Jitter 216.218.254.202 0.000 0.000 0.480 1.758 12.647 27.332 75.408 12.167 27.332 5.560 3.383 ms 4.33 39.77
Server Jitter 45.33.37.82 0.000 0.145 0.583 1.798 10.740 37.973 283.255 10.157 37.828 13.039 4.014 ms 13.5 277.1
Server Jitter 66.220.9.122 0.000 0.000 0.382 1.531 13.484 21.196 21.314 13.101 21.196 4.253 2.985 ms 2.122 9.06
Server Jitter SHM(0) 0.000 0.000 0.000 0.001 0.002 0.003 14.951 0.002 0.003 0.119 0.003 s 83.9 8201
Server Jitter SHM(1) 0.000 0.245 0.339 0.747 2.529 5.290 99.051 2.190 5.045 1.282 1.037 µs 21.29 1149
Server Offset 104.131.155.175 0.373 1.970 2.467 3.297 4.107 4.566 5.914 1.639 2.596 0.536 3.308 ms 153.4 876.3
Server Offset 162.159.200.1 -8.479 1.341 2.404 3.180 3.916 4.409 39.694 1.512 3.068 1.005 3.173 ms 39.92 1144
Server Offset 169.229.128.134 -41.299 1.473 1.942 2.395 2.932 3.578 15.543 0.991 2.105 1.100 2.397 ms -23.83 1089
Server Offset 173.11.101.155 -16.511 -2.812 -1.806 -0.289 0.756 1.757 4.625 2.562 4.569 0.885 -0.372 ms -10.29 92.93
Server Offset 178.62.68.79 -18.789 -6.419 -2.771 1.342 3.085 7.968 10.492 5.856 14.386 2.453 1.071 ms -4.09 27.31
Server Offset 192.168.1.11 -2.118 -0.376 -0.192 0.072 0.442 0.693 47.922 0.634 1.069 0.609 0.105 ms 55.72 3994
Server Offset 204.17.205.23 -5.925 0.416 0.896 1.889 2.820 3.432 5.554 1.924 3.016 0.642 1.881 ms 11.94 45.71
Server Offset 216.218.192.202 -1.673 0.496 1.457 2.377 3.043 3.868 6.756 1.586 3.372 0.581 2.345 ms 35.98 142.1
Server Offset 216.218.254.202 -11.504 -0.810 1.498 2.367 3.014 3.721 20.637 1.516 4.531 0.913 2.327 ms 11.75 235.5
Server Offset 45.33.37.82 -5.550 1.646 1.979 2.670 3.424 4.162 6.090 1.444 2.517 0.517 2.673 ms 83.75 422.6
Server Offset 66.220.9.122 -0.349 1.174 2.004 2.495 2.927 3.866 5.102 0.923 2.692 0.420 2.495 ms 134.3 743.3
Server Offset SHM(0) -0.088 -0.055 -0.054 -0.049 -0.045 -0.043 14.901 0.009 0.012 0.074 -0.049 s 184.7 3.66e+04
Server Offset SHM(1) -0.000 -0.000 -0.000 0.000 0.000 0.000 66.076 0.000 0.000 0.178 0.001 s 303.1 1.076e+05
TDOP 0.500 0.540 0.590 0.810 1.270 1.530 2.100 0.680 0.990 0.215 0.858 37.26 156.3
Temp ZONE0 49.926 50.464 51.540 53.692 59.072 60.148 64.990 7.532 9.684 2.390 54.616 °C
nSats 6.000 7.000 8.000 10.000 11.000 12.000 12.000 3.000 5.000 1.020 9.569 nSat 613.3 5354
Summary as CSV file


Glossary:

frequency offset:
The difference between the ntpd calculated frequency and the local system clock frequency (usually in parts per million, ppm)
jitter, dispersion:
The short term change in a value. NTP measures Local Time Jitter, Refclock Jitter, and Server Jitter in seconds. Local Frequency Jitter is in ppm or ppb.
kurtosis, Kurt:
The kurtosis of a random variable X is the fourth standardized moment and is a dimension-less ratio. ntpviz uses the Pearson's moment coefficient of kurtosis. A normal distribution has a kurtosis of three. NIST describes a kurtosis over three as "heavy tailed" and one under three as "light tailed".
ms, millisecond:
One thousandth of a second = 0.001 seconds, 1e-3 seconds
mu, mean:
The arithmetic mean: the sum of all the values divided by the number of values. The formula for mu is: "mu = (∑xi) / N". Where xi denotes the data points and N is the number of data points.
ns, nanosecond:
One billionth of a second, also one thousandth of a microsecond, 0.000000001 seconds and 1e-9 seconds.
percentile:
The value below which a given percentage of values fall.
ppb, parts per billion:
Ratio between two values. These following are all the same: 1 ppb, one in one billion, 1/1,000,000,000, 0.000,000,001, 1e-9 and 0.000,000,1%
ppm, parts per million:
Ratio between two values. These following are all the same: 1 ppm, one in one million, 1/1,000,000, 0.000,001, and 0.000,1%
‰, parts per thousand:
Ratio between two values. These following are all the same: 1 ‰. one in one thousand, 1/1,000, 0.001, and 0.1%
refclock:
Reference clock, a local GPS module or other local source of time.
remote clock:
Any clock reached over the network, LAN or WAN. Also called a peer or server.
time offset:
The difference between the ntpd calculated time and the local system clock's time. Also called phase offset.
σ, sigma:
Sigma denotes the standard deviation (SD) and is centered on the arithmetic mean of the data set. The SD is simply the square root of the variance of the data set. Two sigma is simply twice the standard deviation. Three sigma is three times sigma. Smaller is better.
The formula for sigma is: "σ = √[ ∑(xi-mu)^2 / N ]". Where xi denotes the data points and N is the number of data points.
skewness, Skew:
The skewness of a random variable X is the third standardized moment and is a dimension-less ratio. ntpviz uses the Pearson's moment coefficient of skewness. Wikipedia describes it best: "The qualitative interpretation of the skew is complicated and unintuitive."
A normal distribution has a skewness of zero.
upstream clock:
Any server or reference clock used as a source of time.
µs, us, microsecond:
One millionth of a second, also one thousandth of a millisecond, 0.000,001 seconds, and 1e-6 seconds.



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