NTPsec

A-ntpsec-72-hour-stats

Report generated: Sun Jun 14 12:09:51 2026 UTC
Start Time: Thu Jun 11 12:09:50 2026 UTC
End Time: Sun Jun 14 12:09:50 2026 UTC
Report published: Sun Jun 14 05:10:21 AM 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 -25.707 -15.933 -1.966 0.194 2.836 4.551 21.443 4.802 20.484 2.718 -0.004 µs -8.231 53.12
Local Clock Frequency Offset -2.004 -1.993 -1.878 -0.072 0.136 0.148 0.177 2.014 2.141 0.733 -0.511 ppm -10.75 32.69

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 0.538 0.663 1.167 8.227 10.348 14.257 7.564 9.810 2.589 2.542 µs 1.463 4.096

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 0.204 0.248 0.441 2.988 4.242 33.734 2.740 4.038 1.178 0.994 ppb 4.993 84.91

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 -25.707 -15.933 -1.966 0.194 2.836 4.551 21.443 4.802 20.484 2.718 -0.004 µs -8.231 53.12

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 -2.004 -1.993 -1.878 -0.072 0.136 0.148 0.177 2.014 2.141 0.733 -0.511 ppm -10.75 32.69
Temp ZONE0 47.236 48.312 48.312 52.078 70.908 70.908 71.446 22.596 22.596 8.977 57.106 °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 12.000 12.000 12.000 4.000 5.000 1.216 9.668 nSat 357.2 2632
TDOP 0.480 0.500 0.530 0.830 1.200 1.450 2.490 0.670 0.950 0.214 0.843 35.27 146.1

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 173.11.101.154

peer offset 173.11.101.154 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 173.11.101.154 -0.004 -0.003 -0.002 0.000 0.003 0.004 181.472 0.005 0.007 16.565 1.525 s 7.299 83.52

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 -2.520 -2.520 -1.638 1.498 2.310 2.570 2.570 3.948 5.090 1.467 0.771 ms -2.285 5.086

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 0.741 1.157 1.864 2.719 4.176 4.587 5.200 2.312 3.430 0.721 2.835 ms 34.46 134

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 0.000 0.001 0.001 0.002 0.003 0.004 181.473 0.002 0.003 6.009 0.201 s 26.33 799

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) 0.787 1.073 1.698 2.528 4.148 4.303 4.832 2.450 3.230 0.720 2.648 ms 27.81 104.3

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 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) 0.956 1.684 2.150 2.865 3.850 4.046 4.880 1.700 2.362 0.585 3.019 ms 84.38 405

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) 0.669 1.591 2.087 2.868 4.377 4.609 5.106 2.290 3.018 0.693 3.042 ms 49.48 209.2

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) 0.822 1.414 1.901 2.757 4.117 4.386 5.947 2.216 2.972 0.627 2.807 ms 53.19 231.7

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 -0.451 0.080 0.716 1.677 3.182 3.547 4.817 2.466 3.467 0.764 1.816 ms 7.071 19.81

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 1.452 1.704 2.278 3.149 4.616 5.112 5.503 2.338 3.408 0.734 3.294 ms 53.39 230.2

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 -0.001 0.001 0.001 0.002 0.003 0.004 181.473 0.002 0.003 6.107 0.208 s 25.85 771.9

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 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) -102.104 -101.521 -100.467 -97.099 -95.014 -94.296 -93.542 5.453 7.224 1.570 -97.331 ms -2.503e+05 1.578e+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) -0.000 -0.000 -0.000 0.000 0.000 0.000 181.471 0.000 0.000 1.006 0.006 s 176.4 3.181e+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 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 173.11.101.154

peer jitter 173.11.101.154 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 173.11.101.154 0.000 0.771 1.310 3.095 15.099 18.861 22.272 13.789 18.089 4.744 5.247 ms 1.796 4.855

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 1.145 1.145 1.482 3.066 5.003 5.517 5.517 3.521 4.373 1.188 3.197 ms 10.12 28.77

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 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 0.368 0.643 1.687 12.201 18.605 42.255 11.558 18.237 4.119 3.204 ms 2.932 20.61

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 0.307 0.647 1.717 14.293 19.805 33.036 13.645 19.497 4.499 3.676 ms 1.643 6.587

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 0.638 0.987 2.329 14.754 23.535 25.278 13.766 22.897 4.856 4.601 ms 1.704 5.946

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) 0.216 0.309 0.505 1.411 9.885 15.595 15.858 9.381 15.286 3.087 2.346 ms 2.331 9.197

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 0.287 0.698 1.890 13.835 20.320 41.056 13.138 20.032 4.854 3.864 ms 2.613 15.96

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 0.372 0.640 1.927 14.961 21.831 30.779 14.321 21.458 4.732 3.760 ms 1.835 7.561

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 0.442 0.733 1.968 14.247 20.432 47.406 13.514 19.991 4.994 3.998 ms 2.811 19.75

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 0.346 0.801 2.180 16.291 25.499 31.413 15.489 25.153 5.407 4.570 ms 1.632 6.196

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 0.305 0.712 1.738 14.005 20.231 39.330 13.293 19.927 4.518 3.687 ms 1.846 8.666

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 0.209 0.270 0.567 1.279 1.758 2.517 1.009 1.550 0.320 0.646 ms 5.471 18.41

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 0.332 0.472 1.100 7.939 16.541 24.957 7.467 16.209 3.051 2.254 µs 2.226 11.33

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 -2.004 -1.993 -1.878 -0.072 0.136 0.148 0.177 2.014 2.141 0.733 -0.511 ppm -10.75 32.69
Local Clock Time Offset -25.707 -15.933 -1.966 0.194 2.836 4.551 21.443 4.802 20.484 2.718 -0.004 µs -8.231 53.12
Local RMS Frequency Jitter 0.000 0.204 0.248 0.441 2.988 4.242 33.734 2.740 4.038 1.178 0.994 ppb 4.993 84.91
Local RMS Time Jitter 0.001 0.538 0.663 1.167 8.227 10.348 14.257 7.564 9.810 2.589 2.542 µs 1.463 4.096
Server Jitter 173.11.101.154 0.000 0.771 1.310 3.095 15.099 18.861 22.272 13.789 18.089 4.744 5.247 ms 1.796 4.855
Server Jitter 173.11.101.155 1.145 1.145 1.482 3.066 5.003 5.517 5.517 3.521 4.373 1.188 3.197 ms 10.12 28.77
Server Jitter 192.12.19.20 0.000 0.368 0.643 1.687 12.201 18.605 42.255 11.558 18.237 4.119 3.204 ms 2.932 20.61
Server Jitter 2001:5a8:601:4005::36 0.000 0.307 0.647 1.717 14.293 19.805 33.036 13.645 19.497 4.499 3.676 ms 1.643 6.587
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.000 0.638 0.987 2.329 14.754 23.535 25.278 13.766 22.897 4.856 4.601 ms 1.704 5.946
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.216 0.309 0.505 1.411 9.885 15.595 15.858 9.381 15.286 3.087 2.346 ms 2.331 9.197
Server Jitter 2607:5300:205:200::90d0 (fjord.txryan.com) 0.000 0.287 0.698 1.890 13.835 20.320 41.056 13.138 20.032 4.854 3.864 ms 2.613 15.96
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.000 0.372 0.640 1.927 14.961 21.831 30.779 14.321 21.458 4.732 3.760 ms 1.835 7.561
Server Jitter 50.116.42.84 0.000 0.442 0.733 1.968 14.247 20.432 47.406 13.514 19.991 4.994 3.998 ms 2.811 19.75
Server Jitter 52.10.183.132 0.000 0.346 0.801 2.180 16.291 25.499 31.413 15.489 25.153 5.407 4.570 ms 1.632 6.196
Server Jitter 66.220.9.122 0.000 0.305 0.712 1.738 14.005 20.231 39.330 13.293 19.927 4.518 3.687 ms 1.846 8.666
Server Jitter SHM(0) 0.000 0.209 0.270 0.567 1.279 1.758 2.517 1.009 1.550 0.320 0.646 ms 5.471 18.41
Server Jitter SHM(1) 0.000 0.332 0.472 1.100 7.939 16.541 24.957 7.467 16.209 3.051 2.254 µs 2.226 11.33
Server Offset 173.11.101.154 -0.004 -0.003 -0.002 0.000 0.003 0.004 181.472 0.005 0.007 16.565 1.525 s 7.299 83.52
Server Offset 173.11.101.155 -2.520 -2.520 -1.638 1.498 2.310 2.570 2.570 3.948 5.090 1.467 0.771 ms -2.285 5.086
Server Offset 192.12.19.20 0.741 1.157 1.864 2.719 4.176 4.587 5.200 2.312 3.430 0.721 2.835 ms 34.46 134
Server Offset 2001:5a8:601:4005::36 0.000 0.001 0.001 0.002 0.003 0.004 181.473 0.002 0.003 6.009 0.201 s 26.33 799
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.787 1.073 1.698 2.528 4.148 4.303 4.832 2.450 3.230 0.720 2.648 ms 27.81 104.3
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 0.956 1.684 2.150 2.865 3.850 4.046 4.880 1.700 2.362 0.585 3.019 ms 84.38 405
Server Offset 2607:5300:205:200::90d0 (fjord.txryan.com) 0.669 1.591 2.087 2.868 4.377 4.609 5.106 2.290 3.018 0.693 3.042 ms 49.48 209.2
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.822 1.414 1.901 2.757 4.117 4.386 5.947 2.216 2.972 0.627 2.807 ms 53.19 231.7
Server Offset 50.116.42.84 -0.451 0.080 0.716 1.677 3.182 3.547 4.817 2.466 3.467 0.764 1.816 ms 7.071 19.81
Server Offset 52.10.183.132 1.452 1.704 2.278 3.149 4.616 5.112 5.503 2.338 3.408 0.734 3.294 ms 53.39 230.2
Server Offset 66.220.9.122 -0.001 0.001 0.001 0.002 0.003 0.004 181.473 0.002 0.003 6.107 0.208 s 25.85 771.9
Server Offset SHM(0) -102.104 -101.521 -100.467 -97.099 -95.014 -94.296 -93.542 5.453 7.224 1.570 -97.331 ms -2.503e+05 1.578e+07
Server Offset SHM(1) -0.000 -0.000 -0.000 0.000 0.000 0.000 181.471 0.000 0.000 1.006 0.006 s 176.4 3.181e+04
TDOP 0.480 0.500 0.530 0.830 1.200 1.450 2.490 0.670 0.950 0.214 0.843 35.27 146.1
Temp ZONE0 47.236 48.312 48.312 52.078 70.908 70.908 71.446 22.596 22.596 8.977 57.106 °C
nSats 6.000 7.000 8.000 10.000 12.000 12.000 12.000 4.000 5.000 1.216 9.668 nSat 357.2 2632
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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