NTPsec

Pi5/UputronicsV2

Report generated: Thu Aug 29 15:53:22 2019 UTC
Start Time: Thu Aug 22 15:53:02 2019 UTC
End Time: Thu Aug 29 15:53:02 2019 UTC
Report Period: 7.0 days

Daily stats   Weekly stats   24 Hour scatter plots ( 1, 2, 3 )

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 -127.845 -104.131 -16.166 0.003 25.293 84.075 118.938 41.459 188.206 21.666 0.947 ms -4.64 26.68
Local Clock Frequency Offset -281.776 -173.870 -112.596 -5.666 143.132 207.791 354.456 255.728 381.660 70.518 4.229 ppm -3.177 9.035

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 0.001 0.008 0.027 8.332 57.817 77.550 101.671 57.790 77.542 19.918 17.134 ms 0.835 3.191

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 0.0010 0.0041 0.025 5.802 42.596 56.838 85.668 42.572 56.834 13.859 11.381 ppm 1.068 4.171

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 -127.845 -104.131 -16.166 0.003 25.293 84.075 118.938 41.459 188.206 21.666 0.947 ms -4.64 26.68

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 -281.776 -173.870 -112.596 -5.666 143.132 207.791 354.456 255.728 381.660 70.518 4.229 ppm -3.177 9.035
Temp ZONE0 44.008 45.084 46.160 49.926 52.078 53.692 54.230 5.918 8.608 1.936 49.490 °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 3.000 7.000 7.000 10.000 12.000 13.000 14.000 5.000 6.000 1.432 9.588 nSat 202.1 1253
TDOP 0.540 0.630 0.670 0.960 1.520 1.900 7.850 0.850 1.270 0.301 1.017 23.28 113.5

Local GPS. The Time Dilution of Precision (TDOP) is plotted in blue. The number of visible satellites (nSat) is plotted in red.

TDOP is field 3, and nSats is field 4, from the gpsd log file. The gpsd log file is created by the ntploggps program.

TDOP is a dimensionless error factor. 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 2001:470:e815::23 (pi3.rellim.com)

peer offset 2001:470:e815::23 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::23 (pi3.rellim.com) -36.165 -19.960 -13.027 0.059 41.874 84.429 105.398 54.901 104.390 17.381 3.757 ms 0.314 8.711

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

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

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

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



Server Offset 2001:470:e815::8 (spidey.rellim.com)

peer offset 2001:470:e815::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::8 (spidey.rellim.com) -33.506 -20.374 -12.619 0.039 26.003 83.318 122.217 38.622 103.692 16.140 3.027 ms 0.4232 11.02

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 204.17.205.1

peer offset 204.17.205.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.1 -34.468 -20.252 -12.796 0.130 26.879 83.902 114.629 39.675 104.154 15.860 3.049 ms 0.4119 10.79

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 204.17.205.16

peer offset 204.17.205.16 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.16 -135.318 -55.237 -17.393 -0.395 31.946 84.676 113.836 49.339 139.913 19.387 1.729 ms -2.326 15.62

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 204.17.205.17

peer offset 204.17.205.17 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.17 -68.366 -20.400 -12.667 0.022 27.989 84.543 115.869 40.656 104.943 16.566 3.176 ms 0.2843 10.07

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 -35.256 -21.459 -12.776 0.042 27.693 78.435 101.587 40.469 99.894 15.809 2.967 ms 0.1756 9.63

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 204.17.205.27

peer offset 204.17.205.27 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.27 -34.678 -20.668 -12.995 0.012 30.155 80.496 111.213 43.151 101.164 16.123 2.958 ms 0.1512 9.617

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 204.17.205.30

peer offset 204.17.205.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.30 -34.342 -20.703 -12.789 0.033 29.430 84.759 113.832 42.219 105.462 16.783 3.353 ms 0.3592 9.759

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) -186.334 -164.536 -155.430 -137.259 -108.326 -55.460 -10.556 47.104 109.077 17.503 -135.142 ms -687 6167

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) -1.032 -1.015 -1.007 -0.107 0.016 0.067 0.119 1.024 1.083 0.498 -0.488 s -13.76 40.26

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

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

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

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



Server Jitters

peer jitters plot

The RMS Jitter of all refclocks and servers. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2001:470:e815::23 (pi3.rellim.com)

peer jitter 2001:470:e815::23 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::23 (pi3.rellim.com) 0.006 0.014 0.031 2.404 49.704 81.898 105.633 49.673 81.884 18.196 10.634 ms 0.9723 5.259

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 2001:470:e815::8 (spidey.rellim.com)

peer jitter 2001:470:e815::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 0.006 0.012 0.024 1.066 48.258 70.545 97.783 48.234 70.532 15.532 7.481 ms 1.026 5.858

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 204.17.205.1

peer jitter 204.17.205.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.1 0.006 0.014 0.026 1.085 49.857 67.367 83.064 49.831 67.353 15.604 7.579 ms 0.9599 5.423

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 204.17.205.16

peer jitter 204.17.205.16 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.16 0.010 0.051 0.140 1.649 53.797 73.828 104.881 53.657 73.777 17.405 9.435 ms 0.8686 4.669

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 204.17.205.17

peer jitter 204.17.205.17 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.17 0.004 0.010 0.025 1.138 51.286 72.161 94.594 51.261 72.151 16.286 7.919 ms 0.936 5.338

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 0.003 0.009 0.021 1.120 50.201 67.900 81.750 50.180 67.891 15.728 7.724 ms 0.9251 5.15

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 204.17.205.27

peer jitter 204.17.205.27 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.27 0.002 0.010 0.029 1.138 51.127 70.621 96.356 51.098 70.611 15.887 7.698 ms 0.978 5.531

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 204.17.205.30

peer jitter 204.17.205.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.30 0.005 0.011 0.021 1.082 50.007 71.761 96.460 49.986 71.750 16.135 7.788 ms 0.974 5.551

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) 0.251 0.717 1.052 2.757 37.967 57.666 76.760 36.916 56.949 11.730 6.797 ms 1.798 8.093

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) 0.000 0.000 0.376 0.756 0.969 1.001 1.049 0.593 1.001 0.220 0.723 s 17.34 50.74

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 -281.776 -173.870 -112.596 -5.666 143.132 207.791 354.456 255.728 381.660 70.518 4.229 ppm -3.177 9.035
Local Clock Time Offset -127.845 -104.131 -16.166 0.003 25.293 84.075 118.938 41.459 188.206 21.666 0.947 ms -4.64 26.68
Local RMS Frequency Jitter 0.0010 0.0041 0.025 5.802 42.596 56.838 85.668 42.572 56.834 13.859 11.381 ppm 1.068 4.171
Local RMS Time Jitter 0.001 0.008 0.027 8.332 57.817 77.550 101.671 57.790 77.542 19.918 17.134 ms 0.835 3.191
Server Jitter 2001:470:e815::23 (pi3.rellim.com) 0.006 0.014 0.031 2.404 49.704 81.898 105.633 49.673 81.884 18.196 10.634 ms 0.9723 5.259
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 0.006 0.012 0.024 1.066 48.258 70.545 97.783 48.234 70.532 15.532 7.481 ms 1.026 5.858
Server Jitter 204.17.205.1 0.006 0.014 0.026 1.085 49.857 67.367 83.064 49.831 67.353 15.604 7.579 ms 0.9599 5.423
Server Jitter 204.17.205.16 0.010 0.051 0.140 1.649 53.797 73.828 104.881 53.657 73.777 17.405 9.435 ms 0.8686 4.669
Server Jitter 204.17.205.17 0.004 0.010 0.025 1.138 51.286 72.161 94.594 51.261 72.151 16.286 7.919 ms 0.936 5.338
Server Jitter 204.17.205.24 0.003 0.009 0.021 1.120 50.201 67.900 81.750 50.180 67.891 15.728 7.724 ms 0.9251 5.15
Server Jitter 204.17.205.27 0.002 0.010 0.029 1.138 51.127 70.621 96.356 51.098 70.611 15.887 7.698 ms 0.978 5.531
Server Jitter 204.17.205.30 0.005 0.011 0.021 1.082 50.007 71.761 96.460 49.986 71.750 16.135 7.788 ms 0.974 5.551
Server Jitter SHM(0) 0.251 0.717 1.052 2.757 37.967 57.666 76.760 36.916 56.949 11.730 6.797 ms 1.798 8.093
Server Jitter SHM(1) 0.000 0.000 0.376 0.756 0.969 1.001 1.049 0.593 1.001 0.220 0.723 s 17.34 50.74
Server Offset 2001:470:e815::23 (pi3.rellim.com) -36.165 -19.960 -13.027 0.059 41.874 84.429 105.398 54.901 104.390 17.381 3.757 ms 0.314 8.711
Server Offset 2001:470:e815::8 (spidey.rellim.com) -33.506 -20.374 -12.619 0.039 26.003 83.318 122.217 38.622 103.692 16.140 3.027 ms 0.4232 11.02
Server Offset 204.17.205.1 -34.468 -20.252 -12.796 0.130 26.879 83.902 114.629 39.675 104.154 15.860 3.049 ms 0.4119 10.79
Server Offset 204.17.205.16 -135.318 -55.237 -17.393 -0.395 31.946 84.676 113.836 49.339 139.913 19.387 1.729 ms -2.326 15.62
Server Offset 204.17.205.17 -68.366 -20.400 -12.667 0.022 27.989 84.543 115.869 40.656 104.943 16.566 3.176 ms 0.2843 10.07
Server Offset 204.17.205.24 -35.256 -21.459 -12.776 0.042 27.693 78.435 101.587 40.469 99.894 15.809 2.967 ms 0.1756 9.63
Server Offset 204.17.205.27 -34.678 -20.668 -12.995 0.012 30.155 80.496 111.213 43.151 101.164 16.123 2.958 ms 0.1512 9.617
Server Offset 204.17.205.30 -34.342 -20.703 -12.789 0.033 29.430 84.759 113.832 42.219 105.462 16.783 3.353 ms 0.3592 9.759
Server Offset SHM(0) -186.334 -164.536 -155.430 -137.259 -108.326 -55.460 -10.556 47.104 109.077 17.503 -135.142 ms -687 6167
Server Offset SHM(1) -1.032 -1.015 -1.007 -0.107 0.016 0.067 0.119 1.024 1.083 0.498 -0.488 s -13.76 40.26
TDOP 0.540 0.630 0.670 0.960 1.520 1.900 7.850 0.850 1.270 0.301 1.017 23.28 113.5
Temp ZONE0 44.008 45.084 46.160 49.926 52.078 53.692 54.230 5.918 8.608 1.936 49.490 °C
nSats 3.000 7.000 7.000 10.000 12.000 13.000 14.000 5.000 6.000 1.432 9.588 nSat 202.1 1253
Summary as CSV file


This server:

CPU: Rasberry Pi 3
OS: Gentoo stable
Kernel: 4.4.45, Config
GPS; RPI GPS Add-on V2 GPS HAT
GPS/PPS server: gpsd
NTP server: NTPsec
ntp.conf: current

Notes:

22:00 10 Feb 2017 UTC Change kernel PREEMTP Server to Low Latency
00:00  3 Feb 2017 Cloned from pi4

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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