NTPsec

C-ntpsec-6-hour-stats

Report generated: Tue Jul 7 05:01:32 2020 UTC
Start Time: Mon Jul 6 23:01:31 2020 UTC
End Time: Tue Jul 7 05:01:31 2020 UTC
Report published: Mon Jul 06 22:01:36 2020 PDT
Report Period: 0.2 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 -1,258.000 -836.000 -668.000 -241.000 331.000 593.000 862.000 999.000 1,429.000 311.275 -204.329 ns -9.235 25.28
Local Clock Frequency Offset -5.376 -5.376 -5.376 -5.358 -5.299 -5.295 -5.295 0.077 0.081 0.026 -5.349 ppm -9.018e+06 1.877e+09

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 99.000 120.000 138.000 213.000 287.000 313.000 348.000 149.000 193.000 44.125 212.133 ns 66.69 300.9

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 28.000 33.000 40.000 85.000 130.000 259.000 334.000 90.000 226.000 37.855 87.531 10e-12 8.696 41.59

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 -1,258.000 -836.000 -668.000 -241.000 331.000 593.000 862.000 999.000 1,429.000 311.275 -204.329 ns -9.235 25.28

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 -5.376 -5.376 -5.376 -5.358 -5.299 -5.295 -5.295 0.077 0.081 0.026 -5.349 ppm -9.018e+06 1.877e+09
Temp ZONE0 65.528 65.528 66.604 67.142 67.680 67.680 67.680 1.076 2.152 0.465 66.962 °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 11.000 12.000 12.000 12.000 3.000 3.000 0.844 10.710 nSat 1631 1.947e+04
TDOP 0.530 0.560 0.610 0.770 1.200 1.300 1.330 0.590 0.740 0.178 0.827 60.47 270.5

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 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 0.629 0.629 1.293 1.776 2.334 2.637 2.637 1.040 2.008 0.335 1.791 ms 95.27 474.3

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 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 2.192 2.192 2.360 2.826 3.346 3.772 3.772 0.986 1.580 0.298 2.822 ms 631.4 5575

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 -3.825 -0.993 0.244 1.395 1.882 1.882 2.388 5.708 0.784 0.175 ms -4.412 19.9

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 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 -31.058 -5.742 68.960 127.045 152.053 163.844 132.787 183.111 37.939 65.014 µs 2.108 5.601

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 2.689 3.135 3.672 4.133 4.971 4.971 0.998 2.282 0.342 3.685 ms 960.9 9686

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 1.835 1.835 2.049 2.524 3.133 3.779 3.779 1.084 1.944 0.356 2.525 ms 246.5 1642

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 5.967 5.967 6.070 6.691 7.076 7.224 7.224 1.006 1.257 0.305 6.636 ms 9040 1.892e+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 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 1.313 1.773 2.307 2.911 3.339 3.339 1.138 2.026 0.359 2.308 ms 176.2 1050

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 -5.813 2.288 4.299 5.569 9.084 9.084 3.281 14.897 1.943 3.996 ms 1.925 12.05

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 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 -2.244 3.266 5.695 6.570 6.570 7.940 12.880 2.651 2.724 ms -1.578 5.878

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 -69.099 -67.210 -57.569 -50.012 -48.611 -47.974 17.197 20.488 5.114 -58.250 ms -1940 2.451e+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) -1,259.000 -837.000 -669.000 -242.000 332.000 594.000 863.000 1,001.000 1,431.000 311.927 -204.787 ns -9.233 25.26

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 0.560 0.560 0.700 2.309 8.722 9.448 9.448 8.022 8.888 2.323 2.978 ms 2.449 6.704

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 0.207 0.641 2.654 11.746 26.384 26.384 11.106 26.177 5.376 4.867 ms 2.262 9.349

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 0.950 0.950 1.232 2.636 11.227 55.777 55.777 9.995 54.827 9.563 5.595 ms 2.755 13.72

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 0.024 0.025 0.047 0.159 8.686 8.718 12.178 8.639 8.693 2.787 1.429 ms 0.3904 2.972

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) 0.502 0.502 0.753 2.090 16.642 28.340 28.340 15.890 27.839 5.909 5.107 ms 1.784 7.133

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 0.417 0.417 0.543 2.014 46.964 47.037 47.037 46.420 46.619 12.470 7.171 ms 1.291 5.288

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 0.344 0.482 2.574 9.441 14.024 14.024 8.959 13.681 3.387 3.867 ms 1.698 4.714

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 0.236 0.458 1.716 9.753 11.095 11.095 9.295 10.859 2.936 2.884 ms 1.69 4.442

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) 0.445 0.445 0.769 2.586 13.282 16.689 16.689 12.513 16.244 4.107 4.391 ms 1.678 4.853

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 2.302 17.324 27.947 27.947 17.324 27.947 6.535 4.642 ms 1.158 5.107

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 0.305 0.598 2.435 8.064 9.887 11.282 7.466 9.582 2.373 3.186 ms 2.103 5.472

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) 58.000 87.000 108.000 217.000 437.000 525.000 706.000 329.000 438.000 102.391 238.768 ns 7.465 24.17

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 -5.376 -5.376 -5.376 -5.358 -5.299 -5.295 -5.295 0.077 0.081 0.026 -5.349 ppm -9.018e+06 1.877e+09
Local Clock Time Offset -1,258.000 -836.000 -668.000 -241.000 331.000 593.000 862.000 999.000 1,429.000 311.275 -204.329 ns -9.235 25.28
Local RMS Frequency Jitter 28.000 33.000 40.000 85.000 130.000 259.000 334.000 90.000 226.000 37.855 87.531 10e-12 8.696 41.59
Local RMS Time Jitter 99.000 120.000 138.000 213.000 287.000 313.000 348.000 149.000 193.000 44.125 212.133 ns 66.69 300.9
Server Jitter 162.159.200.1 0.560 0.560 0.700 2.309 8.722 9.448 9.448 8.022 8.888 2.323 2.978 ms 2.449 6.704
Server Jitter 164.67.62.194 0.207 0.207 0.641 2.654 11.746 26.384 26.384 11.106 26.177 5.376 4.867 ms 2.262 9.349
Server Jitter 173.11.101.155 0.950 0.950 1.232 2.636 11.227 55.777 55.777 9.995 54.827 9.563 5.595 ms 2.755 13.72
Server Jitter 192.168.1.10 0.024 0.025 0.047 0.159 8.686 8.718 12.178 8.639 8.693 2.787 1.429 ms 0.3904 2.972
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.502 0.502 0.753 2.090 16.642 28.340 28.340 15.890 27.839 5.909 5.107 ms 1.784 7.133
Server Jitter 204.123.2.5 0.417 0.417 0.543 2.014 46.964 47.037 47.037 46.420 46.619 12.470 7.171 ms 1.291 5.288
Server Jitter 2405:fc00:0:1::123 0.344 0.344 0.482 2.574 9.441 14.024 14.024 8.959 13.681 3.387 3.867 ms 1.698 4.714
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.236 0.236 0.458 1.716 9.753 11.095 11.095 9.295 10.859 2.936 2.884 ms 1.69 4.442
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.445 0.445 0.769 2.586 13.282 16.689 16.689 12.513 16.244 4.107 4.391 ms 1.678 4.853
Server Jitter 47.51.249.154 0.000 0.000 0.000 2.302 17.324 27.947 27.947 17.324 27.947 6.535 4.642 ms 1.158 5.107
Server Jitter SHM(0) 0.182 0.305 0.598 2.435 8.064 9.887 11.282 7.466 9.582 2.373 3.186 ms 2.103 5.472
Server Jitter SHM(1) 58.000 87.000 108.000 217.000 437.000 525.000 706.000 329.000 438.000 102.391 238.768 ns 7.465 24.17
Server Offset 162.159.200.1 0.629 0.629 1.293 1.776 2.334 2.637 2.637 1.040 2.008 0.335 1.791 ms 95.27 474.3
Server Offset 164.67.62.194 2.192 2.192 2.360 2.826 3.346 3.772 3.772 0.986 1.580 0.298 2.822 ms 631.4 5575
Server Offset 173.11.101.155 -3.825 -3.825 -0.993 0.244 1.395 1.882 1.882 2.388 5.708 0.784 0.175 ms -4.412 19.9
Server Offset 192.168.1.10 -55.218 -31.058 -5.742 68.960 127.045 152.053 163.844 132.787 183.111 37.939 65.014 µs 2.108 5.601
Server Offset 2001:470:e815::24 (pi4.rellim.com) 2.689 2.689 3.135 3.672 4.133 4.971 4.971 0.998 2.282 0.342 3.685 ms 960.9 9686
Server Offset 204.123.2.5 1.835 1.835 2.049 2.524 3.133 3.779 3.779 1.084 1.944 0.356 2.525 ms 246.5 1642
Server Offset 2405:fc00:0:1::123 5.967 5.967 6.070 6.691 7.076 7.224 7.224 1.006 1.257 0.305 6.636 ms 9040 1.892e+05
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 1.313 1.313 1.773 2.307 2.911 3.339 3.339 1.138 2.026 0.359 2.308 ms 176.2 1050
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) -5.813 -5.813 2.288 4.299 5.569 9.084 9.084 3.281 14.897 1.943 3.996 ms 1.925 12.05
Server Offset 47.51.249.154 -6.309 -6.309 -2.244 3.266 5.695 6.570 6.570 7.940 12.880 2.651 2.724 ms -1.578 5.878
Server Offset SHM(0) -69.790 -69.099 -67.210 -57.569 -50.012 -48.611 -47.974 17.197 20.488 5.114 -58.250 ms -1940 2.451e+04
Server Offset SHM(1) -1,259.000 -837.000 -669.000 -242.000 332.000 594.000 863.000 1,001.000 1,431.000 311.927 -204.787 ns -9.233 25.26
TDOP 0.530 0.560 0.610 0.770 1.200 1.300 1.330 0.590 0.740 0.178 0.827 60.47 270.5
Temp ZONE0 65.528 65.528 66.604 67.142 67.680 67.680 67.680 1.076 2.152 0.465 66.962 °C
nSats 9.000 9.000 9.000 11.000 12.000 12.000 12.000 3.000 3.000 0.844 10.710 nSat 1631 1.947e+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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