NTPsec

ntpsec-72-hour-stats

Report generated: Wed Oct 23 20:12:53 2019 UTC
Start Time: Sun Oct 20 20:12:28 2019 UTC
End Time: Wed Oct 23 20:12:28 2019 UTC
Report published: Wed Oct 23 13:14:09 2019 PDT
Report Period: 3.0 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 -1,810.000 -885.000 -602.000 32.000 573.000 791.000 1,536.000 1,175.000 1,676.000 368.851 17.798 ns -3.935 10.21
Local Clock Frequency Offset -748.550 -746.384 -729.858 -564.590 -514.023 -503.204 -502.304 215.835 243.180 64.881 -583.898 ppb -1031 1.064e+04

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 95.000 111.000 160.000 229.000 270.000 333.000 118.000 175.000 36.693 163.798 ns 52.61 228.8

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 18.000 26.000 32.000 74.000 224.000 406.000 728.000 192.000 380.000 72.158 93.252 10e-12 3.901 20.39

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 -1,810.000 -885.000 -602.000 32.000 573.000 791.000 1,536.000 1,175.000 1,676.000 368.851 17.798 ns -3.935 10.21

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 -746.384 -729.858 -564.590 -514.023 -503.204 -502.304 215.835 243.180 64.881 -583.898 ppb -1031 1.064e+04
Temp ZONE0 59.072 59.072 59.610 60.686 62.300 62.838 63.376 2.690 3.766 0.816 60.757 °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 1.281 9.370 nSat 270.7 1829
TDOP 0.500 0.560 0.600 0.820 1.400 1.690 3.660 0.800 1.130 0.263 0.889 21.86 84.91

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 -3.457 -0.511 0.698 2.444 4.904 8.449 200.812 4.205 8.960 11.242 3.125 ms 14.72 257.1

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 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 -2.557 -0.187 6.226 9.399 10.111 10.758 9.586 12.668 3.018 5.268 ms 2.054 4.427

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 -3.684 -0.456 -0.146 0.013 0.168 0.445 200.958 0.313 0.901 4.444 0.152 ms 33.49 1362

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 -196.386 -0.834 -0.289 -0.070 0.746 1.543 188.626 1.035 2.378 5.974 -0.013 ms -11.09 950.5

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 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 -1.219 -0.759 5.116 8.244 9.682 24.858 9.003 10.901 3.017 4.436 ms 1.902 8.747

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 -0.201 0.785 1.175 1.761 2.863 4.172 11.877 1.688 3.387 0.760 1.885 ms 13.82 123.8

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 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 -4.786 1.886 2.064 2.586 3.695 4.559 8.037 1.631 2.673 0.642 2.686 ms 41.63 200

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 1.592 2.119 2.582 3.644 4.439 6.370 1.525 2.847 0.527 2.689 ms 83.05 426.9

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 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) -79.209 -63.080 -60.405 -52.597 -45.139 -43.253 -40.562 15.266 19.828 4.605 -52.561 ms -1950 2.468e+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) -1,811.000 -886.000 -603.000 33.000 574.000 792.000 1,537.000 1,177.000 1,678.000 369.628 17.858 ns -3.934 10.19

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 2.065 75.667 163.083 199.751 75.667 163.083 31.133 13.553 ms 1.423 9.332

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 0.725 0.923 1.411 3.914 77.271 101.191 103.233 75.859 100.268 26.628 16.212 ms 0.6509 2.988

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 0.000 0.109 0.214 1.361 106.481 130.579 353.194 106.267 130.470 41.626 27.494 ms 0.4441 4.851

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 0.000 0.141 0.248 1.221 76.677 131.506 317.480 76.429 131.365 33.289 16.547 ms 1.022 8.291

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 0.452 0.576 0.907 3.930 76.608 107.923 136.012 75.701 107.347 27.652 16.591 ms 0.6969 3.458

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 0.239 0.414 0.720 2.750 76.917 111.897 162.583 76.198 111.484 29.018 16.475 ms 0.5885 3.569

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 0.262 0.395 0.769 2.892 76.635 104.666 156.290 75.866 104.270 26.593 14.415 ms 0.7959 4.395

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 0.244 0.455 0.720 3.096 101.139 131.439 151.430 100.419 130.984 32.584 18.434 ms 0.5878 3.482

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) 0.063 0.329 0.475 1.178 3.057 5.114 16.134 2.582 4.784 0.942 1.425 ms 4.183 22.56

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 61.000 82.000 159.000 339.000 464.000 836.000 257.000 403.000 83.314 178.014 ns 6.535 24.46

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 -746.384 -729.858 -564.590 -514.023 -503.204 -502.304 215.835 243.180 64.881 -583.898 ppb -1031 1.064e+04
Local Clock Time Offset -1,810.000 -885.000 -602.000 32.000 573.000 791.000 1,536.000 1,175.000 1,676.000 368.851 17.798 ns -3.935 10.21
Local RMS Frequency Jitter 18.000 26.000 32.000 74.000 224.000 406.000 728.000 192.000 380.000 72.158 93.252 10e-12 3.901 20.39
Local RMS Time Jitter 76.000 95.000 111.000 160.000 229.000 270.000 333.000 118.000 175.000 36.693 163.798 ns 52.61 228.8
Server Jitter 104.131.155.175 0.000 0.000 0.000 2.065 75.667 163.083 199.751 75.667 163.083 31.133 13.553 ms 1.423 9.332
Server Jitter 178.62.68.79 0.725 0.923 1.411 3.914 77.271 101.191 103.233 75.859 100.268 26.628 16.212 ms 0.6509 2.988
Server Jitter 192.168.1.11 0.000 0.109 0.214 1.361 106.481 130.579 353.194 106.267 130.470 41.626 27.494 ms 0.4441 4.851
Server Jitter 192.168.1.12 0.000 0.141 0.248 1.221 76.677 131.506 317.480 76.429 131.365 33.289 16.547 ms 1.022 8.291
Server Jitter 203.123.48.219 0.452 0.576 0.907 3.930 76.608 107.923 136.012 75.701 107.347 27.652 16.591 ms 0.6969 3.458
Server Jitter 204.17.205.24 0.239 0.414 0.720 2.750 76.917 111.897 162.583 76.198 111.484 29.018 16.475 ms 0.5885 3.569
Server Jitter 216.218.192.202 0.262 0.395 0.769 2.892 76.635 104.666 156.290 75.866 104.270 26.593 14.415 ms 0.7959 4.395
Server Jitter 216.218.254.202 0.244 0.455 0.720 3.096 101.139 131.439 151.430 100.419 130.984 32.584 18.434 ms 0.5878 3.482
Server Jitter SHM(0) 0.063 0.329 0.475 1.178 3.057 5.114 16.134 2.582 4.784 0.942 1.425 ms 4.183 22.56
Server Jitter SHM(1) 27.000 61.000 82.000 159.000 339.000 464.000 836.000 257.000 403.000 83.314 178.014 ns 6.535 24.46
Server Offset 104.131.155.175 -3.457 -0.511 0.698 2.444 4.904 8.449 200.812 4.205 8.960 11.242 3.125 ms 14.72 257.1
Server Offset 178.62.68.79 -3.387 -2.557 -0.187 6.226 9.399 10.111 10.758 9.586 12.668 3.018 5.268 ms 2.054 4.427
Server Offset 192.168.1.11 -3.684 -0.456 -0.146 0.013 0.168 0.445 200.958 0.313 0.901 4.444 0.152 ms 33.49 1362
Server Offset 192.168.1.12 -196.386 -0.834 -0.289 -0.070 0.746 1.543 188.626 1.035 2.378 5.974 -0.013 ms -11.09 950.5
Server Offset 203.123.48.219 -1.564 -1.219 -0.759 5.116 8.244 9.682 24.858 9.003 10.901 3.017 4.436 ms 1.902 8.747
Server Offset 204.17.205.24 -0.201 0.785 1.175 1.761 2.863 4.172 11.877 1.688 3.387 0.760 1.885 ms 13.82 123.8
Server Offset 216.218.192.202 -4.786 1.886 2.064 2.586 3.695 4.559 8.037 1.631 2.673 0.642 2.686 ms 41.63 200
Server Offset 216.218.254.202 1.275 1.592 2.119 2.582 3.644 4.439 6.370 1.525 2.847 0.527 2.689 ms 83.05 426.9
Server Offset SHM(0) -79.209 -63.080 -60.405 -52.597 -45.139 -43.253 -40.562 15.266 19.828 4.605 -52.561 ms -1950 2.468e+04
Server Offset SHM(1) -1,811.000 -886.000 -603.000 33.000 574.000 792.000 1,537.000 1,177.000 1,678.000 369.628 17.858 ns -3.934 10.19
TDOP 0.500 0.560 0.600 0.820 1.400 1.690 3.660 0.800 1.130 0.263 0.889 21.86 84.91
Temp ZONE0 59.072 59.072 59.610 60.686 62.300 62.838 63.376 2.690 3.766 0.816 60.757 °C
nSats 5.000 7.000 7.000 9.000 11.000 12.000 12.000 4.000 5.000 1.281 9.370 nSat 270.7 1829
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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