NTPsec

A-ntpsec-6-hour-stats

Report generated: Sun Aug 18 18:05:07 2019 UTC
Start Time: Sun Aug 18 12:05:05 2019 UTC
End Time: Sun Aug 18 18:05:05 2019 UTC
Report published: Sun Aug 18 11:05:18 2019 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 -472.000 -327.000 -222.000 56.000 357.000 491.000 811.000 579.000 818.000 175.801 62.775 ns -2.027 5.264
Local Clock Frequency Offset -595.078 -594.986 -594.604 -581.604 -574.051 -573.486 -573.395 20.553 21.500 6.463 -582.969 ppb -7.587e+05 6.922e+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 95.000 109.000 129.000 182.000 251.000 285.000 332.000 122.000 176.000 37.008 184.788 ns 76.09 360.2

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 20.000 26.000 28.000 42.000 73.000 89.000 105.000 45.000 63.000 13.301 44.658 10e-12 21.47 81.41

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 -472.000 -327.000 -222.000 56.000 357.000 491.000 811.000 579.000 818.000 175.801 62.775 ns -2.027 5.264

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 -595.078 -594.986 -594.604 -581.604 -574.051 -573.486 -573.395 20.553 21.500 6.463 -582.969 ppb -7.587e+05 6.922e+07
Temp ZONE0 59.072 59.072 59.072 60.148 60.148 60.686 60.686 1.076 1.614 0.396 59.888 °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 1.335 8.815 nSat 193.3 1186
TDOP 0.590 0.590 0.620 0.870 1.640 1.760 5.360 1.020 1.170 0.386 0.960 12.47 94.89

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 1.329 1.329 1.799 3.232 3.955 4.192 4.192 2.156 2.864 0.691 3.013 ms 47.28 188.7

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 -4.423 -4.423 -4.138 -1.869 3.304 4.695 4.695 7.441 9.117 2.346 -1.161 ms -7.077 16.8

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 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 -63.612 -46.688 -30.835 6.916 55.634 93.447 118.680 86.469 140.135 26.686 7.481 µs -1.861 5.736

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 -54.038 -35.388 -26.642 10.682 62.100 91.744 106.151 88.742 127.132 26.375 13.279 µs -1.054 3.955

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 0.913 0.913 1.056 1.562 2.322 2.909 2.909 1.267 1.996 0.443 1.635 ms 27.95 103.1

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 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 1.083 1.083 1.271 1.796 2.172 2.248 2.248 0.901 1.165 0.247 1.781 ms 256.9 1704

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 1.959 1.959 2.240 2.521 2.745 2.830 2.830 0.505 0.872 0.163 2.514 ms 3038 4.439e+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 66.220.9.122

peer offset 66.220.9.122 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 66.220.9.122 2.046 2.046 2.221 2.510 2.764 2.901 2.901 0.543 0.856 0.155 2.505 ms 3500 5.358e+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(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) -65.867 -59.164 -56.830 -48.375 -44.837 -43.840 -42.349 11.993 15.324 3.903 -49.641 ms -2624 3.659e+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) -473.000 -328.000 -223.000 57.000 358.000 492.000 812.000 581.000 820.000 176.522 63.028 ns -2.032 5.262

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 0.280 0.280 0.391 1.358 99.408 149.076 149.076 99.017 148.796 28.936 9.925 ms 1.748 10.16

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 0.000 0.000 0.494 3.189 14.213 66.010 66.010 13.719 66.010 12.880 6.743 ms 2.493 12.44

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 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 0.012 0.014 0.027 0.118 8.659 8.811 12.262 8.632 8.798 2.509 1.101 ms 0.7011 4.372

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 0.011 0.014 0.026 0.121 8.711 10.135 10.169 8.684 10.121 2.685 1.344 ms 0.5332 3.502

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 0.115 0.115 0.240 0.998 13.071 205.763 205.763 12.830 205.649 32.297 7.484 ms 3.149 22.01

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 0.202 0.202 0.293 1.356 9.181 12.480 12.480 8.888 12.278 2.808 2.432 ms 1.349 4.427

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 0.118 0.118 0.208 0.761 8.898 19.888 19.888 8.691 19.771 3.569 2.076 ms 1.578 8.272

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 66.220.9.122

peer jitter 66.220.9.122 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 66.220.9.122 0.155 0.155 0.241 0.831 8.831 20.095 20.095 8.589 19.940 3.317 2.111 ms 1.807 10.29

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) 0.105 0.342 0.502 1.252 3.110 5.146 13.225 2.607 4.804 0.949 1.488 ms 4.161 19.93

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 69.000 98.000 173.000 329.000 418.000 633.000 231.000 349.000 72.422 188.478 ns 10.1 34.69

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 -595.078 -594.986 -594.604 -581.604 -574.051 -573.486 -573.395 20.553 21.500 6.463 -582.969 ppb -7.587e+05 6.922e+07
Local Clock Time Offset -472.000 -327.000 -222.000 56.000 357.000 491.000 811.000 579.000 818.000 175.801 62.775 ns -2.027 5.264
Local RMS Frequency Jitter 20.000 26.000 28.000 42.000 73.000 89.000 105.000 45.000 63.000 13.301 44.658 10e-12 21.47 81.41
Local RMS Time Jitter 95.000 109.000 129.000 182.000 251.000 285.000 332.000 122.000 176.000 37.008 184.788 ns 76.09 360.2
Server Jitter 104.131.155.175 0.280 0.280 0.391 1.358 99.408 149.076 149.076 99.017 148.796 28.936 9.925 ms 1.748 10.16
Server Jitter 178.62.68.79 0.000 0.000 0.494 3.189 14.213 66.010 66.010 13.719 66.010 12.880 6.743 ms 2.493 12.44
Server Jitter 192.168.1.11 0.012 0.014 0.027 0.118 8.659 8.811 12.262 8.632 8.798 2.509 1.101 ms 0.7011 4.372
Server Jitter 192.168.1.12 0.011 0.014 0.026 0.121 8.711 10.135 10.169 8.684 10.121 2.685 1.344 ms 0.5332 3.502
Server Jitter 203.123.48.219 0.115 0.115 0.240 0.998 13.071 205.763 205.763 12.830 205.649 32.297 7.484 ms 3.149 22.01
Server Jitter 204.17.205.24 0.202 0.202 0.293 1.356 9.181 12.480 12.480 8.888 12.278 2.808 2.432 ms 1.349 4.427
Server Jitter 216.218.254.202 0.118 0.118 0.208 0.761 8.898 19.888 19.888 8.691 19.771 3.569 2.076 ms 1.578 8.272
Server Jitter 66.220.9.122 0.155 0.155 0.241 0.831 8.831 20.095 20.095 8.589 19.940 3.317 2.111 ms 1.807 10.29
Server Jitter SHM(0) 0.105 0.342 0.502 1.252 3.110 5.146 13.225 2.607 4.804 0.949 1.488 ms 4.161 19.93
Server Jitter SHM(1) 50.000 69.000 98.000 173.000 329.000 418.000 633.000 231.000 349.000 72.422 188.478 ns 10.1 34.69
Server Offset 104.131.155.175 1.329 1.329 1.799 3.232 3.955 4.192 4.192 2.156 2.864 0.691 3.013 ms 47.28 188.7
Server Offset 178.62.68.79 -4.423 -4.423 -4.138 -1.869 3.304 4.695 4.695 7.441 9.117 2.346 -1.161 ms -7.077 16.8
Server Offset 192.168.1.11 -63.612 -46.688 -30.835 6.916 55.634 93.447 118.680 86.469 140.135 26.686 7.481 µs -1.861 5.736
Server Offset 192.168.1.12 -54.038 -35.388 -26.642 10.682 62.100 91.744 106.151 88.742 127.132 26.375 13.279 µs -1.054 3.955
Server Offset 203.123.48.219 0.913 0.913 1.056 1.562 2.322 2.909 2.909 1.267 1.996 0.443 1.635 ms 27.95 103.1
Server Offset 204.17.205.24 1.083 1.083 1.271 1.796 2.172 2.248 2.248 0.901 1.165 0.247 1.781 ms 256.9 1704
Server Offset 216.218.254.202 1.959 1.959 2.240 2.521 2.745 2.830 2.830 0.505 0.872 0.163 2.514 ms 3038 4.439e+04
Server Offset 66.220.9.122 2.046 2.046 2.221 2.510 2.764 2.901 2.901 0.543 0.856 0.155 2.505 ms 3500 5.358e+04
Server Offset SHM(0) -65.867 -59.164 -56.830 -48.375 -44.837 -43.840 -42.349 11.993 15.324 3.903 -49.641 ms -2624 3.659e+04
Server Offset SHM(1) -473.000 -328.000 -223.000 57.000 358.000 492.000 812.000 581.000 820.000 176.522 63.028 ns -2.032 5.262
TDOP 0.590 0.590 0.620 0.870 1.640 1.760 5.360 1.020 1.170 0.386 0.960 12.47 94.89
Temp ZONE0 59.072 59.072 59.072 60.148 60.148 60.686 60.686 1.076 1.614 0.396 59.888 °C
nSats 5.000 7.000 7.000 9.000 11.000 12.000 12.000 4.000 5.000 1.335 8.815 nSat 193.3 1186
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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