NTPsec

A-ntpsec-3-hour-stats

Report generated: Tue Jul 7 06:01:14 2020 UTC
Start Time: Tue Jul 7 03:01:14 2020 UTC
End Time: Tue Jul 7 06:01:14 2020 UTC
Report published: Mon Jul 06 23:01:19 2020 PDT
Report Period: 0.1 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 -1.638 -1.051 -0.472 0.657 1.860 2.303 2.623 2.332 3.354 0.722 0.704 µs -0.05026 2.66
Local Clock Frequency Offset -1.517 -1.517 -1.516 -1.493 -1.388 -1.376 -1.374 0.128 0.141 0.043 -1.474 ppm -4.544e+04 1.624e+06

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 260.000 303.000 335.000 535.000 761.000 862.000 1,009.000 426.000 559.000 129.139 532.549 ns 40.25 161.7

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 78.000 85.000 100.000 182.000 498.000 578.000 648.000 398.000 493.000 138.921 245.368 10e-12 3.497 8.476

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 -1.638 -1.051 -0.472 0.657 1.860 2.303 2.623 2.332 3.354 0.722 0.704 µs -0.05026 2.66

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 -1.517 -1.517 -1.516 -1.493 -1.388 -1.376 -1.374 0.128 0.141 0.043 -1.474 ppm -4.544e+04 1.624e+06
Temp ZONE0 67.680 67.680 67.680 68.218 68.756 69.294 69.294 1.076 1.614 0.463 68.242 °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 9.000 9.000 9.000 10.000 12.000 12.000 12.000 3.000 3.000 0.866 10.517 nSat 1418 1.619e+04
TDOP 0.640 0.640 0.660 0.790 1.090 1.330 1.330 0.430 0.690 0.152 0.849 110.2 583.5

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 192.168.1.12

peer offset 192.168.1.12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.12 -1.661 5.431 39.793 85.281 126.305 142.603 152.581 86.512 137.172 25.681 82.926 µs 17.35 54.64

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 2001:1948:210:2::4

peer offset 2001:1948:210:2::4 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:1948:210:2::4 -3.194 -3.194 -3.003 -1.903 -1.129 -0.923 -0.923 1.874 2.271 0.611 -1.921 ms -83.93 405.6

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

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

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

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



Server Offset 2001:470:0:50::2 (clock.fmt.he.net)

peer offset 2001:470:0:50::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) 2.165 2.165 2.345 2.766 3.597 3.762 3.762 1.253 1.597 0.396 2.873 ms 264.3 1786

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 2001:470:e815::24 (pi4.rellim.com)

peer offset 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::24 (pi4.rellim.com) 3.224 3.224 3.389 3.813 4.810 5.616 5.616 1.421 2.392 0.495 3.953 ms 363.1 2712

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

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

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

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



Server Offset 216.218.254.202

peer offset 216.218.254.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 216.218.254.202 1.315 1.315 2.253 2.726 3.456 3.864 3.864 1.203 2.549 0.428 2.729 ms 170.8 1003

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 2405:fc00:0:1::123

peer offset 2405:fc00:0:1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2405:fc00:0:1::123 4.811 4.811 4.881 5.250 7.269 7.564 7.564 2.388 2.753 0.741 5.548 ms 294.6 2073

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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer offset 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 1.728 1.728 2.180 2.710 3.464 3.678 3.678 1.283 1.950 0.387 2.710 ms 233.6 1517

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 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com)

peer offset 2a03:b0c0:1:d0::1f9:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) -4.500 -4.500 -3.794 2.343 4.755 5.566 5.566 8.549 10.066 1.921 2.021 ms -1.798 6.94

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) -67.987 -59.866 -56.759 -52.978 -48.334 -46.372 -44.549 8.425 13.495 2.610 -52.771 ms -9622 2.056e+05

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

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

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

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



Server 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) -1.639 -1.052 -0.473 0.658 1.861 2.304 2.624 2.334 3.356 0.723 0.705 µs -0.05135 2.66

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 192.168.1.12

peer jitter 192.168.1.12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.12 0.019 0.022 0.038 0.144 8.663 8.725 8.736 8.625 8.703 2.172 0.827 ms 1.014 5.667

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 2001:1948:210:2::4

peer jitter 2001:1948:210:2::4 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:1948:210:2::4 1.114 1.114 1.123 2.689 11.735 31.902 31.902 10.612 30.788 5.227 4.052 ms 3.427 18.1

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 2001:470:0:50::2 (clock.fmt.he.net)

peer jitter 2001:470:0:50::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 1.003 1.003 1.153 2.441 8.871 10.137 10.137 7.718 9.134 2.351 3.077 ms 2.941 8.795

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 2001:470:e815::24 (pi4.rellim.com)

peer jitter 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.721 0.721 1.078 2.541 12.087 21.238 21.238 11.009 20.517 4.803 4.886 ms 2.04 6.904

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

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

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 216.218.254.202

peer jitter 216.218.254.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 216.218.254.202 0.477 0.477 0.548 2.120 8.997 9.015 9.015 8.449 8.538 3.312 4.238 ms 1.315 2.39

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 2405:fc00:0:1::123

peer jitter 2405:fc00:0:1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2405:fc00:0:1::123 0.592 0.592 0.758 2.582 7.519 10.000 10.000 6.761 9.408 2.091 3.108 ms 3.264 10.25

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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer jitter 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.408 0.408 1.567 2.753 8.898 8.938 8.938 7.332 8.530 2.605 3.867 ms 2.693 6.352

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 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com)

peer jitter 2a03:b0c0:1:d0::1f9:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.400 0.400 0.572 4.737 11.724 12.439 12.439 11.152 12.039 3.535 5.231 ms 1.853 3.905

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) 0.142 0.340 0.482 1.339 3.749 6.613 15.140 3.266 6.273 1.241 1.699 ms 3.549 17.54

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) 0.160 0.197 0.255 0.513 0.979 1.222 1.434 0.724 1.025 0.221 0.550 µs 8.7 27.95

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -1.517 -1.517 -1.516 -1.493 -1.388 -1.376 -1.374 0.128 0.141 0.043 -1.474 ppm -4.544e+04 1.624e+06
Local Clock Time Offset -1.638 -1.051 -0.472 0.657 1.860 2.303 2.623 2.332 3.354 0.722 0.704 µs -0.05026 2.66
Local RMS Frequency Jitter 78.000 85.000 100.000 182.000 498.000 578.000 648.000 398.000 493.000 138.921 245.368 10e-12 3.497 8.476
Local RMS Time Jitter 260.000 303.000 335.000 535.000 761.000 862.000 1,009.000 426.000 559.000 129.139 532.549 ns 40.25 161.7
Server Jitter 192.168.1.12 0.019 0.022 0.038 0.144 8.663 8.725 8.736 8.625 8.703 2.172 0.827 ms 1.014 5.667
Server Jitter 2001:1948:210:2::4 1.114 1.114 1.123 2.689 11.735 31.902 31.902 10.612 30.788 5.227 4.052 ms 3.427 18.1
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 1.003 1.003 1.153 2.441 8.871 10.137 10.137 7.718 9.134 2.351 3.077 ms 2.941 8.795
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.721 0.721 1.078 2.541 12.087 21.238 21.238 11.009 20.517 4.803 4.886 ms 2.04 6.904
Server Jitter 216.218.254.202 0.477 0.477 0.548 2.120 8.997 9.015 9.015 8.449 8.538 3.312 4.238 ms 1.315 2.39
Server Jitter 2405:fc00:0:1::123 0.592 0.592 0.758 2.582 7.519 10.000 10.000 6.761 9.408 2.091 3.108 ms 3.264 10.25
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.408 0.408 1.567 2.753 8.898 8.938 8.938 7.332 8.530 2.605 3.867 ms 2.693 6.352
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.400 0.400 0.572 4.737 11.724 12.439 12.439 11.152 12.039 3.535 5.231 ms 1.853 3.905
Server Jitter SHM(0) 0.142 0.340 0.482 1.339 3.749 6.613 15.140 3.266 6.273 1.241 1.699 ms 3.549 17.54
Server Jitter SHM(1) 0.160 0.197 0.255 0.513 0.979 1.222 1.434 0.724 1.025 0.221 0.550 µs 8.7 27.95
Server Offset 192.168.1.12 -1.661 5.431 39.793 85.281 126.305 142.603 152.581 86.512 137.172 25.681 82.926 µs 17.35 54.64
Server Offset 2001:1948:210:2::4 -3.194 -3.194 -3.003 -1.903 -1.129 -0.923 -0.923 1.874 2.271 0.611 -1.921 ms -83.93 405.6
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) 2.165 2.165 2.345 2.766 3.597 3.762 3.762 1.253 1.597 0.396 2.873 ms 264.3 1786
Server Offset 2001:470:e815::24 (pi4.rellim.com) 3.224 3.224 3.389 3.813 4.810 5.616 5.616 1.421 2.392 0.495 3.953 ms 363.1 2712
Server Offset 216.218.254.202 1.315 1.315 2.253 2.726 3.456 3.864 3.864 1.203 2.549 0.428 2.729 ms 170.8 1003
Server Offset 2405:fc00:0:1::123 4.811 4.811 4.881 5.250 7.269 7.564 7.564 2.388 2.753 0.741 5.548 ms 294.6 2073
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 1.728 1.728 2.180 2.710 3.464 3.678 3.678 1.283 1.950 0.387 2.710 ms 233.6 1517
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) -4.500 -4.500 -3.794 2.343 4.755 5.566 5.566 8.549 10.066 1.921 2.021 ms -1.798 6.94
Server Offset SHM(0) -67.987 -59.866 -56.759 -52.978 -48.334 -46.372 -44.549 8.425 13.495 2.610 -52.771 ms -9622 2.056e+05
Server Offset SHM(1) -1.639 -1.052 -0.473 0.658 1.861 2.304 2.624 2.334 3.356 0.723 0.705 µs -0.05135 2.66
TDOP 0.640 0.640 0.660 0.790 1.090 1.330 1.330 0.430 0.690 0.152 0.849 110.2 583.5
Temp ZONE0 67.680 67.680 67.680 68.218 68.756 69.294 69.294 1.076 1.614 0.463 68.242 °C
nSats 9.000 9.000 9.000 10.000 12.000 12.000 12.000 3.000 3.000 0.866 10.517 nSat 1418 1.619e+04
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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