NTPsec

ntp03.maillink.ch

Report generated: Thu Apr 3 10:45:02 2025 UTC
Start Time: Thu Mar 27 10:45:00 2025 UTC
End Time: Thu Apr 3 10:45:00 2025 UTC
Report Period: 7.0 days

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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 -66.988 -41.305 -22.643 0.153 23.838 37.528 56.093 46.481 78.833 14.198 0.167 µs -4.143 12.33
Local Clock Frequency Offset -3.016 -2.959 -2.865 -2.753 -2.700 -2.688 -2.666 0.165 0.272 0.055 -2.765 ppm -1.327e+05 6.773e+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 1.626 2.779 3.537 7.659 15.373 19.665 40.535 11.836 16.886 3.836 8.345 µs 6.563 24.45

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 0.027 0.225 0.328 0.686 1.481 2.286 3.350 1.153 2.061 0.398 0.771 ppb 5.643 23.01

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 -66.988 -41.305 -22.643 0.153 23.838 37.528 56.093 46.481 78.833 14.198 0.167 µs -4.143 12.33

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 -3.016 -2.959 -2.865 -2.753 -2.700 -2.688 -2.666 0.165 0.272 0.055 -2.765 ppm -1.327e+05 6.773e+06
Temp ZONE0 48.500 50.700 51.800 54.000 55.100 56.200 57.300 3.300 5.500 1.136 53.678 °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 4.000 7.000 8.000 9.000 11.000 12.000 12.000 3.000 5.000 1.026 9.246 nSat 537.9 4499
TDOP 0.520 0.540 0.600 0.870 1.210 1.500 2.100 0.610 0.960 0.205 0.886 47.44 206.3

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

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

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



Server Offsets

peer offsets plot

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

Clock Offset is field 5 in the peerstats log file.



Server Offset 195.176.26.206

peer offset 195.176.26.206 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 195.176.26.206 -132.425 -104.305 -80.987 -42.631 -5.051 14.862 54.484 75.936 119.167 23.247 -42.717 µs -31.45 118

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 2001:638:610:be01::103 (ptbtime3.ptb.de)

peer offset 2001:638:610:be01::103 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:638:610:be01::103 (ptbtime3.ptb.de) -4.016 -2.792 -2.762 -2.712 -2.660 -2.636 -2.579 0.102 0.155 0.051 -2.713 ms -1.591e+05 8.632e+06

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) 0.082 0.458 0.597 0.733 1.176 1.254 1.363 0.579 0.795 0.171 0.781 ms 56.88 257.5

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

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

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

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



Server Offset 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) -0.083 0.004 0.117 0.856 1.219 1.352 1.402 1.103 1.349 0.278 0.828 ms 12.76 35.75

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 2a00:d78:0:712:94:198:159:11 (nts1.time.nl)

peer offset 2a00:d78:0:712:94:198:159:11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) -387.657 -0.427 -0.340 -0.140 0.593 0.983 16.995 0.932 1.410 13.205 -0.572 ms -31.33 874.8

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 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se)

peer offset 2a01:3f7:2:44::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 3.944 4.301 4.319 4.367 4.414 4.445 7.742 0.095 0.144 0.081 4.368 ms 1.512e+05 8.07e+06

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 2a02:168:420b:4::7b:12 (ntp02.maillink.ch)

peer offset 2a02:168:420b:4::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) -63.702 -49.327 -35.827 1.070 41.952 56.594 81.920 77.779 105.921 23.638 2.117 µs -3.367 7.943

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 2a02:168:420b:d::7b:12 (ntp01.maillink.ch)

peer offset 2a02:168:420b:d::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) -83.346 -39.315 -22.004 11.193 53.121 74.931 109.968 75.125 114.246 23.357 12.503 µs -1.137 4.377

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 85.195.224.28

peer offset 85.195.224.28 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 85.195.224.28 -735.912 -301.236 -196.642 53.646 153.913 208.902 332.702 350.555 510.138 105.796 29.001 µs -4.13 15.13

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 PPS(0)

peer offset PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset PPS(0) -74.393 -45.718 -25.337 2.814 22.489 36.680 72.744 47.826 82.398 15.186 1.296 µs -4.022 12.43

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) -735.066 -583.373 -496.776 -376.569 -328.586 -302.659 -16.426 168.191 280.714 55.514 -388.432 ms -536.1 4505

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(2)

peer offset SHM(2) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(2) -906.234 -0.046 -0.026 0.002 0.021 0.036 0.069 0.048 0.082 9.346 -0.103 ms -100.5 9745

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 195.176.26.206

peer jitter 195.176.26.206 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 195.176.26.206 0.000 0.014 0.020 0.058 0.389 1.120 4.459 0.369 1.106 0.286 0.127 ms 8.941 130.1

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 2001:638:610:be01::103 (ptbtime3.ptb.de)

peer jitter 2001:638:610:be01::103 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:638:610:be01::103 (ptbtime3.ptb.de) 0.000 19.755 27.580 64.118 280.835 500.863 1,292.374 253.255 481.108 101.775 97.823 µs 4.124 31.99

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) 11.756 19.625 27.825 71.481 306.937 537.300 1,008.541 279.112 517.675 104.987 108.898 µs 3.294 19.26

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 19.414 29.030 67.527 367.116 731.353 4,616.426 338.086 711.939 194.698 123.001 µs 12.06 267.9

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 2a00:d78:0:712:94:198:159:11 (nts1.time.nl)

peer jitter 2a00:d78:0:712:94:198:159:11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) 0.000 0.048 0.078 1.455 5.533 15.142 387.719 5.455 15.094 17.561 3.019 ms 14.24 270.1

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 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se)

peer jitter 2a01:3f7:2:44::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 0.000 0.022 0.029 0.071 0.325 0.920 43.254 0.296 0.898 1.358 0.168 ms 27.37 868.6

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

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

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2a02:168:420b:4::7b:12 (ntp02.maillink.ch)

peer jitter 2a02:168:420b:4::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) 0.000 3.568 5.825 17.408 42.957 55.686 86.289 37.132 52.118 11.960 20.229 µs 3.505 10.62

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 2a02:168:420b:d::7b:12 (ntp01.maillink.ch)

peer jitter 2a02:168:420b:d::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) 0.000 13.213 17.762 47.289 359.695 929.978 2,029.785 341.933 916.765 159.067 101.814 µs 3.585 27.58

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 85.195.224.28

peer jitter 85.195.224.28 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 85.195.224.28 0.000 13.910 21.915 75.170 288.669 535.269 1,158.899 266.754 521.359 105.362 110.301 µs 3.124 19.47

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 PPS(0)

peer jitter PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter PPS(0) 0.000 0.362 0.834 1.828 3.220 4.735 26.085 2.386 4.373 0.815 1.905 µs 8.308 48.59

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 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 4.759 7.568 27.759 102.426 164.829 529.831 94.859 160.070 36.837 38.350 ms 3.975 31.79

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(2)

peer jitter SHM(2) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(2) 0.000 0.001 0.001 0.006 0.018 0.025 906.242 0.017 0.025 13.213 0.382 ms 43.14 2494

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 -3.016 -2.959 -2.865 -2.753 -2.700 -2.688 -2.666 0.165 0.272 0.055 -2.765 ppm -1.327e+05 6.773e+06
Local Clock Time Offset -66.988 -41.305 -22.643 0.153 23.838 37.528 56.093 46.481 78.833 14.198 0.167 µs -4.143 12.33
Local RMS Frequency Jitter 0.027 0.225 0.328 0.686 1.481 2.286 3.350 1.153 2.061 0.398 0.771 ppb 5.643 23.01
Local RMS Time Jitter 1.626 2.779 3.537 7.659 15.373 19.665 40.535 11.836 16.886 3.836 8.345 µs 6.563 24.45
Server Jitter 195.176.26.206 0.000 0.014 0.020 0.058 0.389 1.120 4.459 0.369 1.106 0.286 0.127 ms 8.941 130.1
Server Jitter 2001:638:610:be01::103 (ptbtime3.ptb.de) 0.000 19.755 27.580 64.118 280.835 500.863 1,292.374 253.255 481.108 101.775 97.823 µs 4.124 31.99
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 11.756 19.625 27.825 71.481 306.937 537.300 1,008.541 279.112 517.675 104.987 108.898 µs 3.294 19.26
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 0.000 19.414 29.030 67.527 367.116 731.353 4,616.426 338.086 711.939 194.698 123.001 µs 12.06 267.9
Server Jitter 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) 0.000 0.048 0.078 1.455 5.533 15.142 387.719 5.455 15.094 17.561 3.019 ms 14.24 270.1
Server Jitter 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 0.000 0.022 0.029 0.071 0.325 0.920 43.254 0.296 0.898 1.358 0.168 ms 27.37 868.6
Server Jitter 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) 0.000 3.568 5.825 17.408 42.957 55.686 86.289 37.132 52.118 11.960 20.229 µs 3.505 10.62
Server Jitter 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) 0.000 13.213 17.762 47.289 359.695 929.978 2,029.785 341.933 916.765 159.067 101.814 µs 3.585 27.58
Server Jitter 85.195.224.28 0.000 13.910 21.915 75.170 288.669 535.269 1,158.899 266.754 521.359 105.362 110.301 µs 3.124 19.47
Server Jitter PPS(0) 0.000 0.362 0.834 1.828 3.220 4.735 26.085 2.386 4.373 0.815 1.905 µs 8.308 48.59
Server Jitter SHM(0) 0.000 4.759 7.568 27.759 102.426 164.829 529.831 94.859 160.070 36.837 38.350 ms 3.975 31.79
Server Jitter SHM(2) 0.000 0.001 0.001 0.006 0.018 0.025 906.242 0.017 0.025 13.213 0.382 ms 43.14 2494
Server Offset 195.176.26.206 -132.425 -104.305 -80.987 -42.631 -5.051 14.862 54.484 75.936 119.167 23.247 -42.717 µs -31.45 118
Server Offset 2001:638:610:be01::103 (ptbtime3.ptb.de) -4.016 -2.792 -2.762 -2.712 -2.660 -2.636 -2.579 0.102 0.155 0.051 -2.713 ms -1.591e+05 8.632e+06
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.082 0.458 0.597 0.733 1.176 1.254 1.363 0.579 0.795 0.171 0.781 ms 56.88 257.5
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -0.083 0.004 0.117 0.856 1.219 1.352 1.402 1.103 1.349 0.278 0.828 ms 12.76 35.75
Server Offset 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) -387.657 -0.427 -0.340 -0.140 0.593 0.983 16.995 0.932 1.410 13.205 -0.572 ms -31.33 874.8
Server Offset 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 3.944 4.301 4.319 4.367 4.414 4.445 7.742 0.095 0.144 0.081 4.368 ms 1.512e+05 8.07e+06
Server Offset 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) -63.702 -49.327 -35.827 1.070 41.952 56.594 81.920 77.779 105.921 23.638 2.117 µs -3.367 7.943
Server Offset 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) -83.346 -39.315 -22.004 11.193 53.121 74.931 109.968 75.125 114.246 23.357 12.503 µs -1.137 4.377
Server Offset 85.195.224.28 -735.912 -301.236 -196.642 53.646 153.913 208.902 332.702 350.555 510.138 105.796 29.001 µs -4.13 15.13
Server Offset PPS(0) -74.393 -45.718 -25.337 2.814 22.489 36.680 72.744 47.826 82.398 15.186 1.296 µs -4.022 12.43
Server Offset SHM(0) -735.066 -583.373 -496.776 -376.569 -328.586 -302.659 -16.426 168.191 280.714 55.514 -388.432 ms -536.1 4505
Server Offset SHM(2) -906.234 -0.046 -0.026 0.002 0.021 0.036 0.069 0.048 0.082 9.346 -0.103 ms -100.5 9745
TDOP 0.520 0.540 0.600 0.870 1.210 1.500 2.100 0.610 0.960 0.205 0.886 47.44 206.3
Temp ZONE0 48.500 50.700 51.800 54.000 55.100 56.200 57.300 3.300 5.500 1.136 53.678 °C
nSats 4.000 7.000 8.000 9.000 11.000 12.000 12.000 3.000 5.000 1.026 9.246 nSat 537.9 4499
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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