NTPsec

A-ntpsec-24-hour-stats

Report generated: Wed Oct 23 20:09:46 2019 UTC
Start Time: Tue Oct 22 20:09:37 2019 UTC
End Time: Wed Oct 23 20:09:37 2019 UTC
Report published: Wed Oct 23 13:10:21 2019 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 -1,196.000 -767.000 -602.000 30.000 596.000 767.000 1,237.000 1,198.000 1,534.000 383.057 13.563 ns -3.864 8.939
Local Clock Frequency Offset -748.550 -747.879 -744.690 -609.451 -520.004 -518.112 -517.776 224.686 229.767 79.782 -621.249 ppb -705 6434

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 76.000 91.000 106.000 155.000 221.000 261.000 318.000 115.000 170.000 34.872 158.146 ns 55.42 244.1

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 19.000 26.000 32.000 90.000 185.000 251.000 353.000 153.000 225.000 49.755 94.074 10e-12 4.414 13.68

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 -1,196.000 -767.000 -602.000 30.000 596.000 767.000 1,237.000 1,198.000 1,534.000 383.057 13.563 ns -3.864 8.939

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 -748.550 -747.879 -744.690 -609.451 -520.004 -518.112 -517.776 224.686 229.767 79.782 -621.249 ppb -705 6434
Temp ZONE0 59.072 59.610 60.148 61.224 62.300 62.838 63.376 2.152 3.228 0.949 61.189 °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 5.000 7.000 7.000 9.000 11.000 12.000 12.000 4.000 5.000 1.284 9.370 nSat 268.8 1813
TDOP 0.500 0.560 0.600 0.830 1.420 1.690 3.660 0.820 1.130 0.270 0.890 20.71 86.52

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. TDOP ranges from 1 to greater than 20. 1 denotes the highest possible confidence level. 2 to 5 is good. Greater than 20 means there will be significant inaccuracy and error.



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 104.131.155.175

peer offset 104.131.155.175 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 104.131.155.175 -0.511 0.549 1.292 2.521 4.103 6.059 9.615 2.812 5.510 1.065 2.602 ms 9.638 45.95

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 178.62.68.79

peer offset 178.62.68.79 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 178.62.68.79 -3.387 -3.387 -0.187 3.349 8.803 10.675 10.675 8.990 14.062 2.914 3.672 ms 1.073 3.231

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 192.168.1.11

peer offset 192.168.1.11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.11 -873.328 -271.224 -108.136 24.291 180.449 377.983 821.159 288.585 649.207 110.212 28.545 µs -2.756 20.99

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 192.168.1.12

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 -998.586 -514.665 -293.433 -72.122 166.858 366.072 729.435 460.291 880.737 151.096 -67.234 µs -7.422 24.61

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 203.123.48.219

peer offset 203.123.48.219 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 203.123.48.219 -1.564 -1.192 -0.577 3.703 6.549 7.426 8.965 7.125 8.619 2.241 3.595 ms 1.635 3.536

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 204.17.205.24

peer offset 204.17.205.24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.24 0.559 0.743 1.090 1.811 2.863 3.195 3.455 1.773 2.453 0.502 1.868 ms 28.88 108

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 216.218.192.202

peer offset 216.218.192.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 216.218.192.202 1.578 1.945 2.135 2.707 3.723 4.428 5.627 1.589 2.482 0.532 2.773 ms 88.9 455.6

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 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 1.275 1.364 2.052 2.660 3.623 4.891 6.370 1.570 3.528 0.544 2.708 ms 76.78 391.6

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 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) -73.446 -62.619 -60.153 -52.862 -45.059 -43.339 -40.562 15.094 19.280 4.555 -52.627 ms -2016 2.578e+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) -1,197.000 -768.000 -603.000 31.000 597.000 768.000 1,238.000 1,200.000 1,536.000 383.873 13.609 ns -3.864 8.935

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 104.131.155.175

peer jitter 104.131.155.175 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 104.131.155.175 0.000 0.000 0.000 2.256 70.754 75.620 81.746 70.754 75.620 20.261 9.923 ms 0.8361 4.227

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 178.62.68.79

peer jitter 178.62.68.79 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 178.62.68.79 0.780 0.780 1.025 3.914 75.582 103.233 103.233 74.557 102.453 21.670 11.015 ms 1.262 5.614

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 192.168.1.11

peer jitter 192.168.1.11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.11 0.055 0.119 0.247 1.417 106.333 108.485 130.787 106.086 108.365 39.131 26.659 ms 0.05944 1.71

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 192.168.1.12

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 0.105 0.162 0.284 1.264 75.042 76.163 194.626 74.758 76.001 22.269 9.432 ms 1.571 12.13

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 203.123.48.219

peer jitter 203.123.48.219 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 203.123.48.219 0.538 0.556 0.912 4.078 76.272 107.531 108.336 75.361 106.974 26.128 15.269 ms 0.6988 3.234

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 204.17.205.24

peer jitter 204.17.205.24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.24 0.417 0.430 0.771 2.461 75.558 86.009 111.897 74.787 85.579 23.022 11.714 ms 0.8097 4.047

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 216.218.192.202

peer jitter 216.218.192.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 216.218.192.202 0.352 0.358 0.702 2.660 74.988 78.624 89.901 74.286 78.266 18.531 8.680 ms 1.422 6.86

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 0.369 0.442 0.711 2.866 75.258 101.711 105.591 74.547 101.268 24.127 12.698 ms 0.8741 4.337

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) 0.078 0.318 0.460 1.165 3.084 5.085 14.627 2.624 4.767 0.950 1.417 ms 4.022 20.73

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) 27.000 58.000 77.000 152.000 312.000 430.000 627.000 235.000 372.000 75.047 168.515 ns 7.039 24.31

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 -748.550 -747.879 -744.690 -609.451 -520.004 -518.112 -517.776 224.686 229.767 79.782 -621.249 ppb -705 6434
Local Clock Time Offset -1,196.000 -767.000 -602.000 30.000 596.000 767.000 1,237.000 1,198.000 1,534.000 383.057 13.563 ns -3.864 8.939
Local RMS Frequency Jitter 19.000 26.000 32.000 90.000 185.000 251.000 353.000 153.000 225.000 49.755 94.074 10e-12 4.414 13.68
Local RMS Time Jitter 76.000 91.000 106.000 155.000 221.000 261.000 318.000 115.000 170.000 34.872 158.146 ns 55.42 244.1
Server Jitter 104.131.155.175 0.000 0.000 0.000 2.256 70.754 75.620 81.746 70.754 75.620 20.261 9.923 ms 0.8361 4.227
Server Jitter 178.62.68.79 0.780 0.780 1.025 3.914 75.582 103.233 103.233 74.557 102.453 21.670 11.015 ms 1.262 5.614
Server Jitter 192.168.1.11 0.055 0.119 0.247 1.417 106.333 108.485 130.787 106.086 108.365 39.131 26.659 ms 0.05944 1.71
Server Jitter 192.168.1.12 0.105 0.162 0.284 1.264 75.042 76.163 194.626 74.758 76.001 22.269 9.432 ms 1.571 12.13
Server Jitter 203.123.48.219 0.538 0.556 0.912 4.078 76.272 107.531 108.336 75.361 106.974 26.128 15.269 ms 0.6988 3.234
Server Jitter 204.17.205.24 0.417 0.430 0.771 2.461 75.558 86.009 111.897 74.787 85.579 23.022 11.714 ms 0.8097 4.047
Server Jitter 216.218.192.202 0.352 0.358 0.702 2.660 74.988 78.624 89.901 74.286 78.266 18.531 8.680 ms 1.422 6.86
Server Jitter 216.218.254.202 0.369 0.442 0.711 2.866 75.258 101.711 105.591 74.547 101.268 24.127 12.698 ms 0.8741 4.337
Server Jitter SHM(0) 0.078 0.318 0.460 1.165 3.084 5.085 14.627 2.624 4.767 0.950 1.417 ms 4.022 20.73
Server Jitter SHM(1) 27.000 58.000 77.000 152.000 312.000 430.000 627.000 235.000 372.000 75.047 168.515 ns 7.039 24.31
Server Offset 104.131.155.175 -0.511 0.549 1.292 2.521 4.103 6.059 9.615 2.812 5.510 1.065 2.602 ms 9.638 45.95
Server Offset 178.62.68.79 -3.387 -3.387 -0.187 3.349 8.803 10.675 10.675 8.990 14.062 2.914 3.672 ms 1.073 3.231
Server Offset 192.168.1.11 -873.328 -271.224 -108.136 24.291 180.449 377.983 821.159 288.585 649.207 110.212 28.545 µs -2.756 20.99
Server Offset 192.168.1.12 -998.586 -514.665 -293.433 -72.122 166.858 366.072 729.435 460.291 880.737 151.096 -67.234 µs -7.422 24.61
Server Offset 203.123.48.219 -1.564 -1.192 -0.577 3.703 6.549 7.426 8.965 7.125 8.619 2.241 3.595 ms 1.635 3.536
Server Offset 204.17.205.24 0.559 0.743 1.090 1.811 2.863 3.195 3.455 1.773 2.453 0.502 1.868 ms 28.88 108
Server Offset 216.218.192.202 1.578 1.945 2.135 2.707 3.723 4.428 5.627 1.589 2.482 0.532 2.773 ms 88.9 455.6
Server Offset 216.218.254.202 1.275 1.364 2.052 2.660 3.623 4.891 6.370 1.570 3.528 0.544 2.708 ms 76.78 391.6
Server Offset SHM(0) -73.446 -62.619 -60.153 -52.862 -45.059 -43.339 -40.562 15.094 19.280 4.555 -52.627 ms -2016 2.578e+04
Server Offset SHM(1) -1,197.000 -768.000 -603.000 31.000 597.000 768.000 1,238.000 1,200.000 1,536.000 383.873 13.609 ns -3.864 8.935
TDOP 0.500 0.560 0.600 0.830 1.420 1.690 3.660 0.820 1.130 0.270 0.890 20.71 86.52
Temp ZONE0 59.072 59.610 60.148 61.224 62.300 62.838 63.376 2.152 3.228 0.949 61.189 °C
nSats 5.000 7.000 7.000 9.000 11.000 12.000 12.000 4.000 5.000 1.284 9.370 nSat 268.8 1813
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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