NTPsec

C-ntpsec-24-hour-stats

Report generated: Tue Jul 7 05:02:01 2020 UTC
Start Time: Mon Jul 6 05:02:00 2020 UTC
End Time: Tue Jul 7 05:02:00 2020 UTC
Report published: Mon Jul 06 22:02:06 2020 PDT
Report Period: 1.0 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 -1,266.000 -756.000 -560.000 28.000 628.000 883.000 1,781.000 1,188.000 1,639.000 371.704 23.561 ns -3.506 8.475
Local Clock Frequency Offset -5.401 -5.399 -5.381 -5.289 -5.219 -5.215 -5.214 0.162 0.184 0.057 -5.293 ppm -8.259e+05 7.751e+07

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 99.000 119.000 138.000 199.000 285.000 330.000 548.000 147.000 211.000 45.397 203.050 ns 53.16 235

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 26.000 33.000 41.000 81.000 151.000 244.000 362.000 110.000 211.000 39.986 87.182 10e-12 7.23 30.58

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 -1,266.000 -756.000 -560.000 28.000 628.000 883.000 1,781.000 1,188.000 1,639.000 371.704 23.561 ns -3.506 8.475

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 -5.401 -5.399 -5.381 -5.289 -5.219 -5.215 -5.214 0.162 0.184 0.057 -5.293 ppm -8.259e+05 7.751e+07
Temp ZONE0 63.376 64.452 64.452 66.066 67.680 67.680 67.680 3.228 3.228 1.017 65.981 °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 1.242 9.704 nSat 336.7 2435
TDOP 0.530 0.550 0.600 0.810 1.240 1.530 1.750 0.640 0.980 0.209 0.851 39.43 163.2

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 162.159.200.1

peer offset 162.159.200.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 162.159.200.1 -0.721 1.012 1.164 1.688 2.981 3.665 3.787 1.816 2.653 0.558 1.802 ms 18.88 70.68

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 164.67.62.194

peer offset 164.67.62.194 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 164.67.62.194 1.498 2.043 2.352 2.702 3.165 3.562 3.772 0.813 1.519 0.268 2.727 ms 800.7 7613

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 -3.825 -2.122 -0.730 0.228 1.089 1.670 1.882 1.818 3.792 0.594 0.196 ms -3.814 18.58

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 192.168.1.10

peer offset 192.168.1.10 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.10 -55.218 -27.972 -11.789 60.499 121.220 151.518 167.263 133.009 179.490 38.931 57.475 µs 1.461 4.267

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) 2.689 2.737 3.115 3.552 4.039 4.238 4.971 0.924 1.501 0.294 3.563 ms 1410 1.607e+04

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

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

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

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



Server Offset 204.123.2.5

peer offset 204.123.2.5 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.123.2.5 0.300 1.835 2.050 2.410 2.845 3.149 3.779 0.795 1.314 0.315 2.410 ms 312.7 2205

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 3.204 3.833 4.248 6.196 7.007 7.260 7.437 2.759 3.427 1.084 5.705 ms 90.05 437.1

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

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

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

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



Server Offset 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) 1.313 1.483 1.696 2.162 2.719 3.260 3.339 1.023 1.776 0.311 2.191 ms 238.9 1566

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) -5.813 -4.931 -1.354 4.549 6.467 12.230 13.291 7.821 17.160 2.693 3.836 ms 0.8061 5.83

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 47.51.249.154

peer offset 47.51.249.154 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 47.51.249.154 -6.309 -6.309 -1.010 3.573 6.553 27.451 27.451 7.563 33.760 3.932 3.640 ms 2.978 22.43

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) -69.790 -67.505 -63.873 -54.851 -46.202 -44.209 -43.296 17.671 23.296 5.301 -55.013 ms -1507 1.755e+04

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

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

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

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



Server Offset 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) -1,267.000 -757.000 -561.000 29.000 629.000 884.000 1,782.000 1,190.000 1,641.000 372.487 23.608 ns -3.507 8.47

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 162.159.200.1

peer jitter 162.159.200.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 162.159.200.1 0.218 0.312 0.425 1.947 10.481 19.452 21.703 10.056 19.140 3.787 3.541 ms 1.742 6.764

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 164.67.62.194

peer jitter 164.67.62.194 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 164.67.62.194 0.207 0.322 0.470 2.097 12.037 26.207 169.740 11.568 25.885 10.906 4.439 ms 11.02 167.1

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 173.11.101.155

peer jitter 173.11.101.155 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 173.11.101.155 0.392 0.482 0.786 2.023 10.070 46.818 76.630 9.284 46.336 7.480 4.164 ms 4.641 37.79

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 192.168.1.10

peer jitter 192.168.1.10 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.10 0.015 0.024 0.044 0.157 8.697 9.471 162.623 8.653 9.447 12.216 2.477 ms 8.432 105.7

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) 0.236 0.281 0.423 1.809 11.600 28.124 28.340 11.176 27.843 4.508 3.601 ms 2.357 12.3

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 204.123.2.5

peer jitter 204.123.2.5 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.123.2.5 0.156 0.168 0.360 1.836 10.561 133.411 133.523 10.201 133.243 16.688 5.798 ms 4.283 34.07

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 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 0.344 0.402 0.537 1.983 10.041 14.444 32.113 9.504 14.042 4.073 3.804 ms 2.542 14.97

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) 0.236 0.262 0.415 1.610 10.534 32.730 243.980 10.120 32.469 20.541 5.098 ms 8.27 97.81

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) 0.157 0.245 0.393 1.687 11.204 69.894 71.315 10.811 69.649 7.719 3.927 ms 5.283 46.44

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 47.51.249.154

peer jitter 47.51.249.154 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 47.51.249.154 0.000 0.000 0.000 1.679 16.541 27.947 27.947 16.541 27.947 5.765 3.830 ms 1.219 5.839

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) 0.182 0.346 0.534 2.292 6.885 8.738 11.282 6.351 8.392 2.111 2.887 ms 2.062 5.255

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) 50.000 80.000 109.000 215.000 464.000 606.000 1,109.000 355.000 526.000 114.443 242.205 ns 6.241 22.52

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 -5.401 -5.399 -5.381 -5.289 -5.219 -5.215 -5.214 0.162 0.184 0.057 -5.293 ppm -8.259e+05 7.751e+07
Local Clock Time Offset -1,266.000 -756.000 -560.000 28.000 628.000 883.000 1,781.000 1,188.000 1,639.000 371.704 23.561 ns -3.506 8.475
Local RMS Frequency Jitter 26.000 33.000 41.000 81.000 151.000 244.000 362.000 110.000 211.000 39.986 87.182 10e-12 7.23 30.58
Local RMS Time Jitter 99.000 119.000 138.000 199.000 285.000 330.000 548.000 147.000 211.000 45.397 203.050 ns 53.16 235
Server Jitter 162.159.200.1 0.218 0.312 0.425 1.947 10.481 19.452 21.703 10.056 19.140 3.787 3.541 ms 1.742 6.764
Server Jitter 164.67.62.194 0.207 0.322 0.470 2.097 12.037 26.207 169.740 11.568 25.885 10.906 4.439 ms 11.02 167.1
Server Jitter 173.11.101.155 0.392 0.482 0.786 2.023 10.070 46.818 76.630 9.284 46.336 7.480 4.164 ms 4.641 37.79
Server Jitter 192.168.1.10 0.015 0.024 0.044 0.157 8.697 9.471 162.623 8.653 9.447 12.216 2.477 ms 8.432 105.7
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.236 0.281 0.423 1.809 11.600 28.124 28.340 11.176 27.843 4.508 3.601 ms 2.357 12.3
Server Jitter 204.123.2.5 0.156 0.168 0.360 1.836 10.561 133.411 133.523 10.201 133.243 16.688 5.798 ms 4.283 34.07
Server Jitter 2405:fc00:0:1::123 0.344 0.402 0.537 1.983 10.041 14.444 32.113 9.504 14.042 4.073 3.804 ms 2.542 14.97
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.236 0.262 0.415 1.610 10.534 32.730 243.980 10.120 32.469 20.541 5.098 ms 8.27 97.81
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.157 0.245 0.393 1.687 11.204 69.894 71.315 10.811 69.649 7.719 3.927 ms 5.283 46.44
Server Jitter 47.51.249.154 0.000 0.000 0.000 1.679 16.541 27.947 27.947 16.541 27.947 5.765 3.830 ms 1.219 5.839
Server Jitter SHM(0) 0.182 0.346 0.534 2.292 6.885 8.738 11.282 6.351 8.392 2.111 2.887 ms 2.062 5.255
Server Jitter SHM(1) 50.000 80.000 109.000 215.000 464.000 606.000 1,109.000 355.000 526.000 114.443 242.205 ns 6.241 22.52
Server Offset 162.159.200.1 -0.721 1.012 1.164 1.688 2.981 3.665 3.787 1.816 2.653 0.558 1.802 ms 18.88 70.68
Server Offset 164.67.62.194 1.498 2.043 2.352 2.702 3.165 3.562 3.772 0.813 1.519 0.268 2.727 ms 800.7 7613
Server Offset 173.11.101.155 -3.825 -2.122 -0.730 0.228 1.089 1.670 1.882 1.818 3.792 0.594 0.196 ms -3.814 18.58
Server Offset 192.168.1.10 -55.218 -27.972 -11.789 60.499 121.220 151.518 167.263 133.009 179.490 38.931 57.475 µs 1.461 4.267
Server Offset 2001:470:e815::24 (pi4.rellim.com) 2.689 2.737 3.115 3.552 4.039 4.238 4.971 0.924 1.501 0.294 3.563 ms 1410 1.607e+04
Server Offset 204.123.2.5 0.300 1.835 2.050 2.410 2.845 3.149 3.779 0.795 1.314 0.315 2.410 ms 312.7 2205
Server Offset 2405:fc00:0:1::123 3.204 3.833 4.248 6.196 7.007 7.260 7.437 2.759 3.427 1.084 5.705 ms 90.05 437.1
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 1.313 1.483 1.696 2.162 2.719 3.260 3.339 1.023 1.776 0.311 2.191 ms 238.9 1566
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) -5.813 -4.931 -1.354 4.549 6.467 12.230 13.291 7.821 17.160 2.693 3.836 ms 0.8061 5.83
Server Offset 47.51.249.154 -6.309 -6.309 -1.010 3.573 6.553 27.451 27.451 7.563 33.760 3.932 3.640 ms 2.978 22.43
Server Offset SHM(0) -69.790 -67.505 -63.873 -54.851 -46.202 -44.209 -43.296 17.671 23.296 5.301 -55.013 ms -1507 1.755e+04
Server Offset SHM(1) -1,267.000 -757.000 -561.000 29.000 629.000 884.000 1,782.000 1,190.000 1,641.000 372.487 23.608 ns -3.507 8.47
TDOP 0.530 0.550 0.600 0.810 1.240 1.530 1.750 0.640 0.980 0.209 0.851 39.43 163.2
Temp ZONE0 63.376 64.452 64.452 66.066 67.680 67.680 67.680 3.228 3.228 1.017 65.981 °C
nSats 6.000 7.000 8.000 10.000 12.000 12.000 12.000 4.000 5.000 1.242 9.704 nSat 336.7 2435
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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