NTPsec

A-ntpsec-72-hour-stats

Report generated: Tue May 12 20:10:01 2026 UTC
Start Time: Sat May 9 20:10:00 2026 UTC
End Time: Tue May 12 20:10:00 2026 UTC
Report published: Tue May 12 01:10:34 PM 2026 PDT
Report Period: 3.0 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 -5.450 -2.173 -1.269 0.029 1.082 1.633 14.404 2.351 3.806 0.753 -0.011 µs -3.895 21.44
Local Clock Frequency Offset -247.955 -245.605 -227.585 -116.074 -9.369 19.608 24.353 218.216 265.213 75.681 -116.171 ppb -23.87 81.31

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 0.001 0.450 0.532 0.835 1.435 1.715 5.093 0.903 1.265 0.285 0.891 µs 17.39 69.78

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 0.174 0.204 0.315 0.555 0.711 39.792 0.351 0.537 0.639 0.358 ppb 39.96 1921

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 -5.450 -2.173 -1.269 0.029 1.082 1.633 14.404 2.351 3.806 0.753 -0.011 µs -3.895 21.44

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 -247.955 -245.605 -227.585 -116.074 -9.369 19.608 24.353 218.216 265.213 75.681 -116.171 ppb -23.87 81.31
Temp ZONE0 46.160 46.160 46.160 47.774 49.388 49.388 51.540 3.228 3.228 0.901 47.884 °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 9.000 12.000 13.000 14.000 4.000 6.000 1.342 9.424 nSat 236.6 1543
TDOP 0.470 0.510 0.540 0.840 1.220 1.350 2.130 0.680 0.840 0.206 0.856 41.38 170.1

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 157.131.224.9

peer offset 157.131.224.9 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 157.131.224.9 0.101 2.105 2.577 2.943 3.261 3.593 5.773 0.684 1.488 0.330 2.922 ms 507.2 4162

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 -4.287 -3.884 -2.945 -0.096 2.625 3.651 4.962 5.570 7.536 1.701 -0.181 ms -4.631 11.21

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 192.12.19.20

peer offset 192.12.19.20 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.12.19.20 -0.758 0.410 1.419 2.790 3.849 4.925 6.316 2.430 4.515 0.747 2.710 ms 25.77 92.85

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 2001:5a8:601:4005::36

peer offset 2001:5a8:601:4005::36 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:5a8:601:4005::36 0.274 0.584 0.965 1.782 3.516 3.607 3.892 2.551 3.023 0.747 1.978 ms 10.27 32.33

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 2606:4700:f1::1 (time.cloudflare.com)

peer offset 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.468 0.894 1.473 2.734 4.099 4.378 4.790 2.626 3.484 0.942 2.936 ms 15.64 47.11

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 2606:4700:f1::123 (time.cloudflare.com)

peer offset 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 1.232 1.820 2.147 2.639 3.089 3.661 7.606 0.942 1.841 0.390 2.654 ms 217.4 1492

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 2607:5300:205:200::7f70

peer offset 2607:5300:205:200::7f70 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:5300:205:200::7f70 2.422 2.422 2.441 2.817 3.302 3.331 3.331 0.861 0.910 0.232 2.813 ms 1414 1.613e+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 2607:5300:205:200::90d0 (fjord.txryan.com)

peer offset 2607:5300:205:200::90d0 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:5300:205:200::90d0 (fjord.txryan.com) 0.541 1.409 1.983 2.805 4.166 4.372 5.140 2.183 2.963 0.656 2.916 ms 51.57 220.8

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 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu)

peer offset 2607:f140:ffff:8000:0:8006:0:a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.611 1.349 1.998 2.754 4.006 4.337 7.837 2.008 2.988 0.565 2.773 ms 72.6 355.9

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 50.116.42.84

peer offset 50.116.42.84 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 50.116.42.84 -0.340 0.098 0.665 1.571 2.867 3.015 3.622 2.202 2.917 0.667 1.676 ms 8.233 23.14

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 52.10.183.132

peer offset 52.10.183.132 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 52.10.183.132 0.351 1.120 1.645 2.605 3.927 4.498 5.546 2.282 3.378 0.703 2.687 ms 31.33 119.3

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 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 0.535 1.041 1.567 2.226 3.120 3.678 3.991 1.554 2.637 0.461 2.218 ms 67.35 313.1

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 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) -135.270 -134.659 -133.000 -129.135 -95.555 -94.383 -92.573 37.444 40.275 16.158 -117.867 ms -595 5131

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) -5.451 -2.174 -1.270 0.030 1.083 1.634 14.405 2.353 3.808 0.754 -0.011 µs -3.895 21.4

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 157.131.224.9

peer jitter 157.131.224.9 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 157.131.224.9 0.216 0.261 0.499 1.622 6.155 18.263 24.265 5.656 18.002 2.846 2.367 ms 4.004 25.09

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 1.330 1.648 3.247 6.805 17.312 20.967 5.157 15.982 2.654 3.819 ms 5.115 27.56

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 192.12.19.20

peer jitter 192.12.19.20 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.12.19.20 0.000 0.304 0.659 1.680 5.683 21.296 49.285 5.024 20.992 3.474 2.522 ms 5.154 48.53

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 2001:5a8:601:4005::36

peer jitter 2001:5a8:601:4005::36 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:5a8:601:4005::36 0.000 0.682 0.986 1.941 5.310 11.835 24.082 4.324 11.153 2.341 2.464 ms 6.293 52.24

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 2606:4700:f1::1 (time.cloudflare.com)

peer jitter 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.000 0.390 0.599 1.859 7.095 19.630 24.383 6.495 19.240 3.119 2.593 ms 4.169 25.28

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 2606:4700:f1::123 (time.cloudflare.com)

peer jitter 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.236 0.409 0.792 1.782 7.691 16.763 31.235 6.899 16.353 3.384 2.685 ms 4.065 27.1

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 2607:5300:205:200::7f70

peer jitter 2607:5300:205:200::7f70 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:5300:205:200::7f70 0.727 0.727 0.805 1.580 3.045 7.104 7.104 2.240 6.377 1.155 1.877 ms 4.97 22.94

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 2607:5300:205:200::90d0 (fjord.txryan.com)

peer jitter 2607:5300:205:200::90d0 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:5300:205:200::90d0 (fjord.txryan.com) 0.000 0.457 0.782 1.806 6.840 20.378 28.161 6.058 19.921 2.968 2.561 ms 4.646 32.14

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 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu)

peer jitter 2607:f140:ffff:8000:0:8006:0:a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.000 0.423 0.767 1.754 6.927 20.679 45.823 6.160 20.257 3.851 2.697 ms 5.55 52.55

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 50.116.42.84

peer jitter 50.116.42.84 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 50.116.42.84 0.000 0.332 0.655 1.648 5.724 18.965 66.975 5.069 18.633 4.612 2.485 ms 8.685 113.4

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 52.10.183.132

peer jitter 52.10.183.132 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 52.10.183.132 0.000 0.281 0.524 1.563 6.284 24.428 75.126 5.760 24.147 4.501 2.646 ms 6.968 91.02

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 0.272 0.643 1.674 5.573 15.964 23.755 4.930 15.693 2.835 2.321 ms 4.189 25.72

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 0.054 0.121 0.507 1.229 1.780 2.805 1.108 1.725 0.354 0.576 ms 3.533 12.46

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 0.296 0.398 0.818 1.811 2.504 7.644 1.413 2.208 0.467 0.926 µs 5.984 28.82

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 -247.955 -245.605 -227.585 -116.074 -9.369 19.608 24.353 218.216 265.213 75.681 -116.171 ppb -23.87 81.31
Local Clock Time Offset -5.450 -2.173 -1.269 0.029 1.082 1.633 14.404 2.351 3.806 0.753 -0.011 µs -3.895 21.44
Local RMS Frequency Jitter 0.000 0.174 0.204 0.315 0.555 0.711 39.792 0.351 0.537 0.639 0.358 ppb 39.96 1921
Local RMS Time Jitter 0.001 0.450 0.532 0.835 1.435 1.715 5.093 0.903 1.265 0.285 0.891 µs 17.39 69.78
Server Jitter 157.131.224.9 0.216 0.261 0.499 1.622 6.155 18.263 24.265 5.656 18.002 2.846 2.367 ms 4.004 25.09
Server Jitter 173.11.101.155 0.000 1.330 1.648 3.247 6.805 17.312 20.967 5.157 15.982 2.654 3.819 ms 5.115 27.56
Server Jitter 192.12.19.20 0.000 0.304 0.659 1.680 5.683 21.296 49.285 5.024 20.992 3.474 2.522 ms 5.154 48.53
Server Jitter 2001:5a8:601:4005::36 0.000 0.682 0.986 1.941 5.310 11.835 24.082 4.324 11.153 2.341 2.464 ms 6.293 52.24
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.000 0.390 0.599 1.859 7.095 19.630 24.383 6.495 19.240 3.119 2.593 ms 4.169 25.28
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.236 0.409 0.792 1.782 7.691 16.763 31.235 6.899 16.353 3.384 2.685 ms 4.065 27.1
Server Jitter 2607:5300:205:200::7f70 0.727 0.727 0.805 1.580 3.045 7.104 7.104 2.240 6.377 1.155 1.877 ms 4.97 22.94
Server Jitter 2607:5300:205:200::90d0 (fjord.txryan.com) 0.000 0.457 0.782 1.806 6.840 20.378 28.161 6.058 19.921 2.968 2.561 ms 4.646 32.14
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.000 0.423 0.767 1.754 6.927 20.679 45.823 6.160 20.257 3.851 2.697 ms 5.55 52.55
Server Jitter 50.116.42.84 0.000 0.332 0.655 1.648 5.724 18.965 66.975 5.069 18.633 4.612 2.485 ms 8.685 113.4
Server Jitter 52.10.183.132 0.000 0.281 0.524 1.563 6.284 24.428 75.126 5.760 24.147 4.501 2.646 ms 6.968 91.02
Server Jitter 66.220.9.122 0.000 0.272 0.643 1.674 5.573 15.964 23.755 4.930 15.693 2.835 2.321 ms 4.189 25.72
Server Jitter SHM(0) 0.000 0.054 0.121 0.507 1.229 1.780 2.805 1.108 1.725 0.354 0.576 ms 3.533 12.46
Server Jitter SHM(1) 0.000 0.296 0.398 0.818 1.811 2.504 7.644 1.413 2.208 0.467 0.926 µs 5.984 28.82
Server Offset 157.131.224.9 0.101 2.105 2.577 2.943 3.261 3.593 5.773 0.684 1.488 0.330 2.922 ms 507.2 4162
Server Offset 173.11.101.155 -4.287 -3.884 -2.945 -0.096 2.625 3.651 4.962 5.570 7.536 1.701 -0.181 ms -4.631 11.21
Server Offset 192.12.19.20 -0.758 0.410 1.419 2.790 3.849 4.925 6.316 2.430 4.515 0.747 2.710 ms 25.77 92.85
Server Offset 2001:5a8:601:4005::36 0.274 0.584 0.965 1.782 3.516 3.607 3.892 2.551 3.023 0.747 1.978 ms 10.27 32.33
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.468 0.894 1.473 2.734 4.099 4.378 4.790 2.626 3.484 0.942 2.936 ms 15.64 47.11
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 1.232 1.820 2.147 2.639 3.089 3.661 7.606 0.942 1.841 0.390 2.654 ms 217.4 1492
Server Offset 2607:5300:205:200::7f70 2.422 2.422 2.441 2.817 3.302 3.331 3.331 0.861 0.910 0.232 2.813 ms 1414 1.613e+04
Server Offset 2607:5300:205:200::90d0 (fjord.txryan.com) 0.541 1.409 1.983 2.805 4.166 4.372 5.140 2.183 2.963 0.656 2.916 ms 51.57 220.8
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.611 1.349 1.998 2.754 4.006 4.337 7.837 2.008 2.988 0.565 2.773 ms 72.6 355.9
Server Offset 50.116.42.84 -0.340 0.098 0.665 1.571 2.867 3.015 3.622 2.202 2.917 0.667 1.676 ms 8.233 23.14
Server Offset 52.10.183.132 0.351 1.120 1.645 2.605 3.927 4.498 5.546 2.282 3.378 0.703 2.687 ms 31.33 119.3
Server Offset 66.220.9.122 0.535 1.041 1.567 2.226 3.120 3.678 3.991 1.554 2.637 0.461 2.218 ms 67.35 313.1
Server Offset SHM(0) -135.270 -134.659 -133.000 -129.135 -95.555 -94.383 -92.573 37.444 40.275 16.158 -117.867 ms -595 5131
Server Offset SHM(1) -5.451 -2.174 -1.270 0.030 1.083 1.634 14.405 2.353 3.808 0.754 -0.011 µs -3.895 21.4
TDOP 0.470 0.510 0.540 0.840 1.220 1.350 2.130 0.680 0.840 0.206 0.856 41.38 170.1
Temp ZONE0 46.160 46.160 46.160 47.774 49.388 49.388 51.540 3.228 3.228 0.901 47.884 °C
nSats 6.000 7.000 8.000 9.000 12.000 13.000 14.000 4.000 6.000 1.342 9.424 nSat 236.6 1543
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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