NTPsec

Pi5/Uputronics

Report generated: Thu Aug 29 18:43:06 2019 UTC
Start Time: Wed Aug 28 18:43:01 2019 UTC
End Time: Thu Aug 29 18:43:01 2019 UTC
Report Period: 1.0 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 -110.903 -17.481 -0.144 36.365 85.845 108.396 53.846 196.747 24.057 0.312 ms -4.812 24.47
Local Clock Frequency Offset -198.640 -147.068 -100.737 1.126 147.931 248.241 354.456 248.668 395.309 73.256 17.064 ppm -2.014 6.453

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 0.007 0.014 0.068 12.471 65.462 79.158 90.813 65.394 79.144 21.600 20.660 ms 0.8928 2.913

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 0.0031 0.0107 0.064 8.155 42.630 53.403 69.195 42.566 53.392 13.879 13.041 ppm 1.081 3.593

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 -110.903 -17.481 -0.144 36.365 85.845 108.396 53.846 196.747 24.057 0.312 ms -4.812 24.47

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 -198.640 -147.068 -100.737 1.126 147.931 248.241 354.456 248.668 395.309 73.256 17.064 ppm -2.014 6.453
Temp ZONE0 48.312 48.312 48.850 50.464 52.616 58.534 60.686 3.766 10.222 1.553 50.674 °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 4.000 6.000 7.000 9.000 12.000 12.000 13.000 5.000 6.000 1.502 9.311 nSat 156 891.8
TDOP 0.580 0.640 0.680 0.980 1.720 2.090 6.150 1.040 1.450 0.379 1.063 15.92 110.3

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) -22.748 -17.094 -13.052 -0.058 41.903 79.806 84.694 54.955 96.899 17.125 3.071 ms -0.01238 7.571

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) -30.588 -23.942 -12.843 -0.050 32.346 82.363 93.143 45.189 106.304 16.352 2.610 ms -0.1022 9.131

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 -29.826 -21.461 -13.235 -0.051 45.208 80.008 97.356 58.443 101.469 17.026 3.161 ms -0.06467 7.884

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 -89.177 -32.390 -14.114 -0.680 30.231 78.532 112.985 44.345 110.922 17.317 1.811 ms -1.37 12.54

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 -32.212 -20.941 -12.640 -0.229 50.321 86.498 92.574 62.961 107.439 17.797 2.910 ms -0.06787 7.863

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 -30.726 -21.459 -13.491 -0.045 43.756 78.721 101.587 57.247 100.180 17.759 3.478 ms -0.15 7.411

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 -33.798 -19.592 -13.092 -0.281 41.515 70.840 88.169 54.607 90.432 15.911 2.350 ms -0.4926 7.447

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 -25.655 -21.139 -12.918 -0.069 51.446 82.417 113.832 64.364 103.556 18.434 3.804 ms 0.006926 7.356

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) -185.185 -165.697 -156.665 -136.822 -99.839 -55.647 -21.160 56.827 110.050 18.560 -134.184 ms -580 4934

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) -1.030 -1.015 -1.008 -0.102 0.017 0.077 0.108 1.025 1.092 0.497 -0.486 s -13.7 40.09

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) 0.010 0.018 0.058 2.988 50.635 79.605 82.694 50.577 79.587 18.700 12.879 ms 0.7361 3.759

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) 0.008 0.016 0.030 1.240 49.066 64.697 75.182 49.036 64.681 16.250 8.861 ms 0.6945 4.019

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 0.007 0.017 0.030 1.180 53.548 66.396 79.177 53.518 66.379 17.315 9.487 ms 0.6266 3.693

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 0.021 0.057 0.132 1.428 50.011 71.331 78.198 49.880 71.275 16.634 9.192 ms 0.7246 4.096

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 0.009 0.022 0.046 1.306 52.918 70.091 79.729 52.871 70.069 17.532 9.425 ms 0.6699 3.925

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 0.007 0.011 0.024 1.425 50.337 66.949 81.504 50.313 66.939 16.988 9.425 ms 0.7297 4.191

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 0.013 0.029 0.058 1.330 50.604 61.206 73.952 50.546 61.177 16.589 9.178 ms 0.595 3.506

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 0.010 0.013 0.023 1.199 52.941 71.968 96.460 52.918 71.955 17.383 9.226 ms 0.7702 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 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) 0.409 0.741 1.078 2.915 44.319 58.176 66.313 43.241 57.435 12.977 7.902 ms 1.4 5.859

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) 350.497 458.910 534.444 791.049 926.267 970.574 1,037.416 391.824 511.665 135.585 770.590 ms 116.1 603.4

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 -198.640 -147.068 -100.737 1.126 147.931 248.241 354.456 248.668 395.309 73.256 17.064 ppm -2.014 6.453
Local Clock Time Offset -127.845 -110.903 -17.481 -0.144 36.365 85.845 108.396 53.846 196.747 24.057 0.312 ms -4.812 24.47
Local RMS Frequency Jitter 0.0031 0.0107 0.064 8.155 42.630 53.403 69.195 42.566 53.392 13.879 13.041 ppm 1.081 3.593
Local RMS Time Jitter 0.007 0.014 0.068 12.471 65.462 79.158 90.813 65.394 79.144 21.600 20.660 ms 0.8928 2.913
Server Jitter 2001:470:e815::23 (pi3.rellim.com) 0.010 0.018 0.058 2.988 50.635 79.605 82.694 50.577 79.587 18.700 12.879 ms 0.7361 3.759
Server Jitter 2001:470:e815::8 (spidey.rellim.com) 0.008 0.016 0.030 1.240 49.066 64.697 75.182 49.036 64.681 16.250 8.861 ms 0.6945 4.019
Server Jitter 204.17.205.1 0.007 0.017 0.030 1.180 53.548 66.396 79.177 53.518 66.379 17.315 9.487 ms 0.6266 3.693
Server Jitter 204.17.205.16 0.021 0.057 0.132 1.428 50.011 71.331 78.198 49.880 71.275 16.634 9.192 ms 0.7246 4.096
Server Jitter 204.17.205.17 0.009 0.022 0.046 1.306 52.918 70.091 79.729 52.871 70.069 17.532 9.425 ms 0.6699 3.925
Server Jitter 204.17.205.24 0.007 0.011 0.024 1.425 50.337 66.949 81.504 50.313 66.939 16.988 9.425 ms 0.7297 4.191
Server Jitter 204.17.205.27 0.013 0.029 0.058 1.330 50.604 61.206 73.952 50.546 61.177 16.589 9.178 ms 0.595 3.506
Server Jitter 204.17.205.30 0.010 0.013 0.023 1.199 52.941 71.968 96.460 52.918 71.955 17.383 9.226 ms 0.7702 4.542
Server Jitter SHM(0) 0.409 0.741 1.078 2.915 44.319 58.176 66.313 43.241 57.435 12.977 7.902 ms 1.4 5.859
Server Jitter SHM(1) 350.497 458.910 534.444 791.049 926.267 970.574 1,037.416 391.824 511.665 135.585 770.590 ms 116.1 603.4
Server Offset 2001:470:e815::23 (pi3.rellim.com) -22.748 -17.094 -13.052 -0.058 41.903 79.806 84.694 54.955 96.899 17.125 3.071 ms -0.01238 7.571
Server Offset 2001:470:e815::8 (spidey.rellim.com) -30.588 -23.942 -12.843 -0.050 32.346 82.363 93.143 45.189 106.304 16.352 2.610 ms -0.1022 9.131
Server Offset 204.17.205.1 -29.826 -21.461 -13.235 -0.051 45.208 80.008 97.356 58.443 101.469 17.026 3.161 ms -0.06467 7.884
Server Offset 204.17.205.16 -89.177 -32.390 -14.114 -0.680 30.231 78.532 112.985 44.345 110.922 17.317 1.811 ms -1.37 12.54
Server Offset 204.17.205.17 -32.212 -20.941 -12.640 -0.229 50.321 86.498 92.574 62.961 107.439 17.797 2.910 ms -0.06787 7.863
Server Offset 204.17.205.24 -30.726 -21.459 -13.491 -0.045 43.756 78.721 101.587 57.247 100.180 17.759 3.478 ms -0.15 7.411
Server Offset 204.17.205.27 -33.798 -19.592 -13.092 -0.281 41.515 70.840 88.169 54.607 90.432 15.911 2.350 ms -0.4926 7.447
Server Offset 204.17.205.30 -25.655 -21.139 -12.918 -0.069 51.446 82.417 113.832 64.364 103.556 18.434 3.804 ms 0.006926 7.356
Server Offset SHM(0) -185.185 -165.697 -156.665 -136.822 -99.839 -55.647 -21.160 56.827 110.050 18.560 -134.184 ms -580 4934
Server Offset SHM(1) -1.030 -1.015 -1.008 -0.102 0.017 0.077 0.108 1.025 1.092 0.497 -0.486 s -13.7 40.09
TDOP 0.580 0.640 0.680 0.980 1.720 2.090 6.150 1.040 1.450 0.379 1.063 15.92 110.3
Temp ZONE0 48.312 48.312 48.850 50.464 52.616 58.534 60.686 3.766 10.222 1.553 50.674 °C
nSats 4.000 6.000 7.000 9.000 12.000 12.000 13.000 5.000 6.000 1.502 9.311 nSat 156 891.8
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
19:00 21 Dec 2016 UTC SD corruption, start all over again...

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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