NTPsec

A-ntpsec-7-day-stats

Report generated: Sun Apr 5 19:11:37 2026 UTC
Start Time: Sun Mar 29 19:11:35 2026 UTC
End Time: Sun Apr 5 19:11:35 2026 UTC
Report published: Sun Apr 05 12:12:14 PM 2026 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 -4.153 -1.954 -1.271 0.061 1.037 1.454 4.855 2.308 3.408 0.701 0.001 µs -4.498 12.8
Local Clock Frequency Offset -690.887 -679.398 -613.602 -422.470 -270.844 -206.146 -200.745 342.758 473.252 104.319 -428.161 ppb -148.5 842.4

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 0.280 0.454 0.545 0.855 1.289 1.493 2.561 0.744 1.039 0.229 0.878 µs 31.66 121.8

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 108.000 176.000 210.000 325.000 479.000 552.000 1,438.000 269.000 376.000 84.211 332.426 10e-12 35.36 146.2

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 -4.153 -1.954 -1.271 0.061 1.037 1.454 4.855 2.308 3.408 0.701 0.001 µs -4.498 12.8

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 -690.887 -679.398 -613.602 -422.470 -270.844 -206.146 -200.745 342.758 473.252 104.319 -428.161 ppb -148.5 842.4
Temp ZONE0 41.856 42.932 42.932 45.084 46.160 47.236 47.774 3.228 4.304 0.973 44.814 °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 7.000 8.000 8.000 10.000 13.000 14.000 15.000 5.000 6.000 1.514 10.138 nSat 202.5 1262
TDOP 0.460 0.490 0.520 0.790 1.200 1.390 1.790 0.680 0.900 0.203 0.824 38.62 156.2

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 -14.419 -9.251 0.921 2.966 4.977 5.391 7.338 4.056 14.643 2.265 2.746 ms -3.585 22.41

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 -6.359 -5.283 -3.985 -0.846 3.042 4.748 8.453 7.027 10.031 2.177 -0.700 ms -5.947 14.77

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 -0.606 0.220 1.097 2.805 4.869 5.568 6.844 3.772 5.349 1.088 2.898 ms 9.872 29.92

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) 0.286 0.815 1.489 2.798 4.633 5.032 5.140 3.144 4.217 1.046 3.024 ms 12.59 37.41

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) -0.164 0.937 1.532 2.721 4.613 4.838 8.915 3.081 3.901 1.022 2.985 ms 13.23 41.63

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::9bc0 (fjord.txryan.com)

peer offset 2607:5300:205:200::9bc0 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:5300:205:200::9bc0 (fjord.txryan.com) -0.481 0.528 1.209 2.494 4.410 5.030 7.737 3.202 4.502 1.080 2.762 ms 8.833 25.62

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) 0.028 0.912 1.722 2.755 4.729 4.971 6.549 3.008 4.059 0.864 2.909 ms 21.1 75.57

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 2a01:4ff:f0:c766::1 (fjord.txryan.com)

peer offset 2a01:4ff:f0:c766::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a01:4ff:f0:c766::1 (fjord.txryan.com) -0.376 0.133 0.978 2.193 4.098 4.239 4.416 3.120 4.106 1.068 2.520 ms 6.621 16.63

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 -0.459 1.327 2.135 3.668 5.666 6.082 7.728 3.531 4.755 1.108 3.845 ms 22.6 77.83

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 -3.442 -2.228 -1.324 2.082 4.154 4.555 6.491 5.478 6.783 1.571 1.991 ms 0.1346 3.167

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 -1.787 0.544 1.270 2.524 4.543 5.031 5.956 3.273 4.488 0.927 2.606 ms 11.96 38.79

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) -137.017 -135.979 -134.387 -130.659 -128.438 -127.545 -126.567 5.949 8.434 1.901 -130.953 ms -3.417e+05 2.39e+07

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) -4.154 -1.955 -1.272 0.062 1.038 1.455 4.856 2.310 3.410 0.702 0.001 µs -4.496 12.79

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 0.420 1.004 1.414 3.416 10.949 28.314 68.007 9.535 27.310 4.689 4.668 ms 5.688 53.59

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 1.016 1.495 1.917 4.145 10.658 29.146 78.634 8.741 27.651 4.898 5.184 ms 7.655 90.95

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 0.362 0.906 1.384 3.239 9.896 22.908 60.307 8.512 22.003 4.062 4.267 ms 6.636 74.63

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 0.932 1.241 2.731 6.962 14.285 22.023 5.721 13.353 2.298 3.305 ms 4.766 27.12

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) 0.000 0.902 1.283 3.182 10.853 19.217 89.032 9.571 18.315 4.949 4.349 ms 9.377 147.3

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::9bc0 (fjord.txryan.com)

peer jitter 2607:5300:205:200::9bc0 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:5300:205:200::9bc0 (fjord.txryan.com) 0.570 0.950 1.309 2.966 10.951 17.951 52.950 9.642 17.001 3.602 4.014 ms 4.732 38.51

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) 0.546 0.954 1.278 3.004 9.617 17.113 179.476 8.339 16.159 5.046 3.991 ms 20.74 695.3

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 2a01:4ff:f0:c766::1 (fjord.txryan.com)

peer jitter 2a01:4ff:f0:c766::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a01:4ff:f0:c766::1 (fjord.txryan.com) 0.470 0.604 1.341 2.830 7.657 22.209 73.151 6.315 21.605 5.257 3.866 ms 8.974 113.9

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 0.384 0.974 1.413 3.110 9.508 25.364 162.665 8.095 24.391 7.224 4.417 ms 10.96 182.2

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 0.685 0.974 1.376 3.098 9.829 21.852 181.123 8.453 20.878 8.783 4.448 ms 14.28 268.1

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 0.536 1.021 1.401 3.180 10.159 17.763 122.400 8.759 16.742 5.022 4.271 ms 10.38 188.5

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) 0.020 0.056 0.104 0.456 1.184 1.709 3.231 1.080 1.652 0.345 0.524 ms 3.132 11.07

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) 0.078 0.287 0.398 0.831 1.698 2.232 5.264 1.300 1.945 0.410 0.909 µs 6.725 23.05

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -690.887 -679.398 -613.602 -422.470 -270.844 -206.146 -200.745 342.758 473.252 104.319 -428.161 ppb -148.5 842.4
Local Clock Time Offset -4.153 -1.954 -1.271 0.061 1.037 1.454 4.855 2.308 3.408 0.701 0.001 µs -4.498 12.8
Local RMS Frequency Jitter 108.000 176.000 210.000 325.000 479.000 552.000 1,438.000 269.000 376.000 84.211 332.426 10e-12 35.36 146.2
Local RMS Time Jitter 0.280 0.454 0.545 0.855 1.289 1.493 2.561 0.744 1.039 0.229 0.878 µs 31.66 121.8
Server Jitter 157.131.224.9 0.420 1.004 1.414 3.416 10.949 28.314 68.007 9.535 27.310 4.689 4.668 ms 5.688 53.59
Server Jitter 173.11.101.155 1.016 1.495 1.917 4.145 10.658 29.146 78.634 8.741 27.651 4.898 5.184 ms 7.655 90.95
Server Jitter 192.12.19.20 0.362 0.906 1.384 3.239 9.896 22.908 60.307 8.512 22.003 4.062 4.267 ms 6.636 74.63
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.000 0.932 1.241 2.731 6.962 14.285 22.023 5.721 13.353 2.298 3.305 ms 4.766 27.12
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.000 0.902 1.283 3.182 10.853 19.217 89.032 9.571 18.315 4.949 4.349 ms 9.377 147.3
Server Jitter 2607:5300:205:200::9bc0 (fjord.txryan.com) 0.570 0.950 1.309 2.966 10.951 17.951 52.950 9.642 17.001 3.602 4.014 ms 4.732 38.51
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.546 0.954 1.278 3.004 9.617 17.113 179.476 8.339 16.159 5.046 3.991 ms 20.74 695.3
Server Jitter 2a01:4ff:f0:c766::1 (fjord.txryan.com) 0.470 0.604 1.341 2.830 7.657 22.209 73.151 6.315 21.605 5.257 3.866 ms 8.974 113.9
Server Jitter 50.116.42.84 0.384 0.974 1.413 3.110 9.508 25.364 162.665 8.095 24.391 7.224 4.417 ms 10.96 182.2
Server Jitter 52.10.183.132 0.685 0.974 1.376 3.098 9.829 21.852 181.123 8.453 20.878 8.783 4.448 ms 14.28 268.1
Server Jitter 66.220.9.122 0.536 1.021 1.401 3.180 10.159 17.763 122.400 8.759 16.742 5.022 4.271 ms 10.38 188.5
Server Jitter SHM(0) 0.020 0.056 0.104 0.456 1.184 1.709 3.231 1.080 1.652 0.345 0.524 ms 3.132 11.07
Server Jitter SHM(1) 0.078 0.287 0.398 0.831 1.698 2.232 5.264 1.300 1.945 0.410 0.909 µs 6.725 23.05
Server Offset 157.131.224.9 -14.419 -9.251 0.921 2.966 4.977 5.391 7.338 4.056 14.643 2.265 2.746 ms -3.585 22.41
Server Offset 173.11.101.155 -6.359 -5.283 -3.985 -0.846 3.042 4.748 8.453 7.027 10.031 2.177 -0.700 ms -5.947 14.77
Server Offset 192.12.19.20 -0.606 0.220 1.097 2.805 4.869 5.568 6.844 3.772 5.349 1.088 2.898 ms 9.872 29.92
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.286 0.815 1.489 2.798 4.633 5.032 5.140 3.144 4.217 1.046 3.024 ms 12.59 37.41
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -0.164 0.937 1.532 2.721 4.613 4.838 8.915 3.081 3.901 1.022 2.985 ms 13.23 41.63
Server Offset 2607:5300:205:200::9bc0 (fjord.txryan.com) -0.481 0.528 1.209 2.494 4.410 5.030 7.737 3.202 4.502 1.080 2.762 ms 8.833 25.62
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.028 0.912 1.722 2.755 4.729 4.971 6.549 3.008 4.059 0.864 2.909 ms 21.1 75.57
Server Offset 2a01:4ff:f0:c766::1 (fjord.txryan.com) -0.376 0.133 0.978 2.193 4.098 4.239 4.416 3.120 4.106 1.068 2.520 ms 6.621 16.63
Server Offset 50.116.42.84 -0.459 1.327 2.135 3.668 5.666 6.082 7.728 3.531 4.755 1.108 3.845 ms 22.6 77.83
Server Offset 52.10.183.132 -3.442 -2.228 -1.324 2.082 4.154 4.555 6.491 5.478 6.783 1.571 1.991 ms 0.1346 3.167
Server Offset 66.220.9.122 -1.787 0.544 1.270 2.524 4.543 5.031 5.956 3.273 4.488 0.927 2.606 ms 11.96 38.79
Server Offset SHM(0) -137.017 -135.979 -134.387 -130.659 -128.438 -127.545 -126.567 5.949 8.434 1.901 -130.953 ms -3.417e+05 2.39e+07
Server Offset SHM(1) -4.154 -1.955 -1.272 0.062 1.038 1.455 4.856 2.310 3.410 0.702 0.001 µs -4.496 12.79
TDOP 0.460 0.490 0.520 0.790 1.200 1.390 1.790 0.680 0.900 0.203 0.824 38.62 156.2
Temp ZONE0 41.856 42.932 42.932 45.084 46.160 47.236 47.774 3.228 4.304 0.973 44.814 °C
nSats 7.000 8.000 8.000 10.000 13.000 14.000 15.000 5.000 6.000 1.514 10.138 nSat 202.5 1262
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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