NTPsec

C-ntpsec-6-hour-stats

Report generated: Wed Oct 23 20:06:12 2019 UTC
Start Time: Wed Oct 23 14:06:12 2019 UTC
End Time: Wed Oct 23 20:06:12 2019 UTC
Report published: Wed Oct 23 13:07:25 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 -769.000 -500.000 -315.000 25.000 414.000 591.000 772.000 729.000 1,091.000 218.976 32.161 ns -3.059 7.954
Local Clock Frequency Offset -7.203 -7.202 -7.202 -7.194 -7.192 -7.192 -7.192 0.0097 0.0107 0.0031 -7.195 ppm -1.304e+10 3.069e+13

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 78.000 99.000 111.000 162.000 245.000 281.000 339.000 134.000 182.000 40.894 167.038 ns 39.35 160.2

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 24.000 29.000 49.000 87.000 104.000 122.000 58.000 80.000 17.527 51.861 10e-12 14.33 49.02

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 -769.000 -500.000 -315.000 25.000 414.000 591.000 772.000 729.000 1,091.000 218.976 32.161 ns -3.059 7.954

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 -7.203 -7.202 -7.202 -7.194 -7.192 -7.192 -7.192 0.0097 0.0107 0.0031 -7.195 ppm -1.304e+10 3.069e+13
Temp ZONE0 63.376 63.376 63.376 63.914 64.452 64.452 64.990 1.076 1.076 0.456 63.908 °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 7.000 7.000 7.000 10.000 11.000 12.000 12.000 4.000 5.000 1.090 9.390 nSat 464.5 3706
TDOP 0.500 0.500 0.600 0.830 1.450 1.480 1.480 0.850 0.980 0.254 0.902 24.98 91.7

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 1.902 1.902 2.060 2.700 4.719 4.955 4.955 2.659 3.053 0.778 2.884 ms 29.12 114.4

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 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 -0.776 -0.776 -0.462 -0.035 0.854 1.293 1.293 1.316 2.069 0.430 0.051 ms -2.342 5.621

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

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

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

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



Server Offset 164.67.62.194

peer offset 164.67.62.194 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 164.67.62.194 1.122 1.122 2.224 2.629 3.135 3.343 3.343 0.911 2.222 0.335 2.638 ms 344.6 2493

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 -0.243 -0.243 -0.168 0.612 1.447 1.876 1.876 1.615 2.120 0.462 0.614 ms 1.28 3.838

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 -1.356 -1.356 -1.249 2.075 5.531 5.531 5.531 6.781 6.888 1.581 1.927 ms 0.4588 3.507

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 -114.916 3.350 84.335 261.507 388.466 548.368 650.522 304.131 545.018 93.984 256.856 µs 10.33 32.4

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 4.263 4.263 4.417 5.289 6.456 6.966 6.966 2.039 2.703 0.550 5.387 ms 705.8 6450

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 1.303 1.303 1.565 2.042 2.859 3.230 3.230 1.294 1.927 0.372 2.076 ms 110.3 582.7

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 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) -66.033 -62.652 -61.732 -54.668 -46.955 -45.457 -44.932 14.777 17.195 4.406 -54.500 ms -2430 3.303e+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) -770.000 -501.000 -316.000 25.000 415.000 592.000 773.000 731.000 1,093.000 219.707 32.279 ns -3.061 7.944

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 2.079 132.443 161.363 161.363 132.443 161.363 48.403 24.538 ms 0.2558 2.58

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 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 0.341 0.341 0.613 2.102 24.468 24.779 24.779 23.854 24.438 5.623 4.201 ms 1.956 7.653

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 0.383 0.383 0.815 2.386 8.872 10.048 10.048 8.057 9.665 2.681 3.590 ms 2.029 4.605

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 0.450 0.450 0.735 2.845 12.115 15.935 15.935 11.379 15.485 3.835 4.425 ms 1.68 4.542

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 1.206 1.206 1.534 2.948 9.376 9.376 9.376 7.842 8.171 2.801 4.066 ms 2.496 5.696

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 0.117 0.142 0.219 1.259 74.988 77.620 82.082 74.769 77.478 20.620 9.334 ms 0.7672 4.304

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 0.454 0.454 0.596 2.855 9.322 9.831 9.831 8.726 9.377 2.716 3.867 ms 2.171 4.981

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 0.467 0.467 0.581 2.478 8.916 9.156 9.156 8.335 8.689 2.986 3.808 ms 1.564 3.163

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) 0.371 0.487 0.673 2.674 6.895 8.385 10.942 6.223 7.898 2.098 3.199 ms 2.414 5.899

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) 28.000 68.000 87.000 188.000 421.000 549.000 691.000 334.000 481.000 104.642 213.554 ns 5.419 17.03

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 -7.203 -7.202 -7.202 -7.194 -7.192 -7.192 -7.192 0.0097 0.0107 0.0031 -7.195 ppm -1.304e+10 3.069e+13
Local Clock Time Offset -769.000 -500.000 -315.000 25.000 414.000 591.000 772.000 729.000 1,091.000 218.976 32.161 ns -3.059 7.954
Local RMS Frequency Jitter 20.000 24.000 29.000 49.000 87.000 104.000 122.000 58.000 80.000 17.527 51.861 10e-12 14.33 49.02
Local RMS Time Jitter 78.000 99.000 111.000 162.000 245.000 281.000 339.000 134.000 182.000 40.894 167.038 ns 39.35 160.2
Server Jitter 104.131.155.175 0.000 0.000 0.000 2.079 132.443 161.363 161.363 132.443 161.363 48.403 24.538 ms 0.2558 2.58
Server Jitter 162.159.200.1 0.341 0.341 0.613 2.102 24.468 24.779 24.779 23.854 24.438 5.623 4.201 ms 1.956 7.653
Server Jitter 164.67.62.194 0.383 0.383 0.815 2.386 8.872 10.048 10.048 8.057 9.665 2.681 3.590 ms 2.029 4.605
Server Jitter 173.11.101.155 0.450 0.450 0.735 2.845 12.115 15.935 15.935 11.379 15.485 3.835 4.425 ms 1.68 4.542
Server Jitter 178.62.68.79 1.206 1.206 1.534 2.948 9.376 9.376 9.376 7.842 8.171 2.801 4.066 ms 2.496 5.696
Server Jitter 192.168.1.10 0.117 0.142 0.219 1.259 74.988 77.620 82.082 74.769 77.478 20.620 9.334 ms 0.7672 4.304
Server Jitter 203.123.48.219 0.454 0.454 0.596 2.855 9.322 9.831 9.831 8.726 9.377 2.716 3.867 ms 2.171 4.981
Server Jitter 204.17.205.24 0.467 0.467 0.581 2.478 8.916 9.156 9.156 8.335 8.689 2.986 3.808 ms 1.564 3.163
Server Jitter SHM(0) 0.371 0.487 0.673 2.674 6.895 8.385 10.942 6.223 7.898 2.098 3.199 ms 2.414 5.899
Server Jitter SHM(1) 28.000 68.000 87.000 188.000 421.000 549.000 691.000 334.000 481.000 104.642 213.554 ns 5.419 17.03
Server Offset 104.131.155.175 1.902 1.902 2.060 2.700 4.719 4.955 4.955 2.659 3.053 0.778 2.884 ms 29.12 114.4
Server Offset 162.159.200.1 -0.776 -0.776 -0.462 -0.035 0.854 1.293 1.293 1.316 2.069 0.430 0.051 ms -2.342 5.621
Server Offset 164.67.62.194 1.122 1.122 2.224 2.629 3.135 3.343 3.343 0.911 2.222 0.335 2.638 ms 344.6 2493
Server Offset 173.11.101.155 -0.243 -0.243 -0.168 0.612 1.447 1.876 1.876 1.615 2.120 0.462 0.614 ms 1.28 3.838
Server Offset 178.62.68.79 -1.356 -1.356 -1.249 2.075 5.531 5.531 5.531 6.781 6.888 1.581 1.927 ms 0.4588 3.507
Server Offset 192.168.1.10 -114.916 3.350 84.335 261.507 388.466 548.368 650.522 304.131 545.018 93.984 256.856 µs 10.33 32.4
Server Offset 203.123.48.219 4.263 4.263 4.417 5.289 6.456 6.966 6.966 2.039 2.703 0.550 5.387 ms 705.8 6450
Server Offset 204.17.205.24 1.303 1.303 1.565 2.042 2.859 3.230 3.230 1.294 1.927 0.372 2.076 ms 110.3 582.7
Server Offset SHM(0) -66.033 -62.652 -61.732 -54.668 -46.955 -45.457 -44.932 14.777 17.195 4.406 -54.500 ms -2430 3.303e+04
Server Offset SHM(1) -770.000 -501.000 -316.000 25.000 415.000 592.000 773.000 731.000 1,093.000 219.707 32.279 ns -3.061 7.944
TDOP 0.500 0.500 0.600 0.830 1.450 1.480 1.480 0.850 0.980 0.254 0.902 24.98 91.7
Temp ZONE0 63.376 63.376 63.376 63.914 64.452 64.452 64.990 1.076 1.076 0.456 63.908 °C
nSats 7.000 7.000 7.000 10.000 11.000 12.000 12.000 4.000 5.000 1.090 9.390 nSat 464.5 3706
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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