NTPsec

b-ntpsec-72-hour-stats

Report generated: Sun Jan 26 14:03:06 2020 UTC
Start Time: Thu Jan 23 14:03:01 2020 UTC
End Time: Sun Jan 26 14:03:01 2020 UTC
Report published: Sun Jan 26 06:03:23 2020 PST
Report Period: 3.0 days

Local Clock Time/Frequency Offsets

local offset plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Time Offset -1.543 -1.022 -0.775 0.004 0.625 0.839 1.235 1.400 1.861 0.427 -0.027 µs -4.635 11.72
Local Clock Frequency Offset -5.884 -5.883 -5.872 -5.791 -5.622 -5.605 -5.603 0.250 0.277 0.072 -5.771 ppm -5.311e+05 4.302e+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 95.000 151.000 181.000 269.000 389.000 450.000 541.000 208.000 299.000 64.407 274.677 ns 45.1 187.4

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 27.000 36.000 44.000 84.000 186.000 218.000 330.000 142.000 182.000 44.747 96.008 10e-12 5.991 18.13

The RMS Frequency Jitter (aka wander) of the local clock's frequency. In other words, how fast the local clock changes frequency.

Lower is better. An ideal clock would be a horizontal line at 0ppm.

RMS Frequency Jitter is field 6 in the loopstats log file.



Local Clock Time Offset Histogram

local offset histogram plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Offset -1.543 -1.022 -0.775 0.004 0.625 0.839 1.235 1.400 1.861 0.427 -0.027 µs -4.635 11.72

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 -5.884 -5.883 -5.872 -5.791 -5.622 -5.605 -5.603 0.250 0.277 0.072 -5.771 ppm -5.311e+05 4.302e+07
Temp ZONE0 60.148 60.148 60.686 62.300 63.376 63.376 63.914 2.690 3.228 0.740 62.091 °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 6.000 7.000 7.000 9.000 12.000 12.000 12.000 5.000 5.000 1.370 9.313 nSat 212.3 1334
TDOP 0.510 0.580 0.610 0.880 1.560 1.870 2.310 0.950 1.290 0.286 0.938 19.97 74.9

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 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 -55.968 27.196 46.852 89.958 119.777 135.036 239.400 72.925 107.840 23.961 86.893 µs 25.42 88.03

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 2001:470:0:50::2 (clock.fmt.he.net)

peer offset 2001:470:0:50::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) -4.138 1.987 2.250 2.578 2.974 3.493 3.804 0.725 1.506 0.387 2.581 ms 189.5 1177

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::24 (pi4.rellim.com)

peer offset 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::24 (pi4.rellim.com) 3.251 3.615 3.879 4.308 4.785 5.087 5.723 0.906 1.472 0.287 4.325 ms 2824 4.033e+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 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 0.891 2.070 2.231 2.545 2.898 3.176 3.295 0.666 1.106 0.229 2.557 ms 1087 1.138e+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 2405:fc00:0:1::123

peer offset 2405:fc00:0:1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2405:fc00:0:1::123 8.643 8.913 9.173 9.634 10.598 10.905 11.330 1.425 1.992 0.431 9.735 ms 1.015e+04 2.208e+05

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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer offset 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -10.191 -9.646 -4.123 2.055 3.748 4.154 4.740 7.870 13.799 2.371 1.748 ms -3.79 16.51

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 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu)

peer offset 2607:f140:ffff:8000:0:8006:0:a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) -0.055 1.997 2.210 2.506 2.880 3.118 3.368 0.671 1.120 0.231 2.521 ms 1004 1.023e+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 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com)

peer offset 2a03:b0c0:1:d0::1f9:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) -8.812 -4.432 -0.935 2.932 6.240 11.089 12.709 7.174 15.521 2.395 2.749 ms 0.4971 6.406

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 76.14.161.109

peer offset 76.14.161.109 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 76.14.161.109 -4.294 -2.580 -1.708 -0.581 0.892 2.550 5.602 2.600 5.130 0.921 -0.518 ms -7.374 22.42

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) -472.314 -412.920 -399.115 -356.921 -312.846 -296.315 -252.124 86.270 116.605 26.192 -356.678 ms -3167 4.694e+04

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

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

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

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



Server Offset SHM(1)

peer offset SHM(1) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(1) -1.544 -1.023 -0.776 0.005 0.625 0.840 1.236 1.401 1.863 0.428 -0.027 µs -4.634 11.71

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 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 0.010 0.025 0.044 0.193 8.654 9.894 56.929 8.609 9.869 2.962 1.663 ms 2.116 33.8

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 2001:470:0:50::2 (clock.fmt.he.net)

peer jitter 2001:470:0:50::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 0.000 0.182 0.328 1.664 9.719 33.958 102.748 9.391 33.775 8.718 3.836 ms 7.043 77.91

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::24 (pi4.rellim.com)

peer jitter 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.230 0.310 0.412 1.788 9.825 18.439 182.592 9.413 18.129 9.971 3.931 ms 10.34 157.4

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.



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 0.097 0.246 0.401 2.037 9.231 10.602 12.681 8.830 10.356 2.926 3.280 ms 1.576 3.926

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 2405:fc00:0:1::123

peer jitter 2405:fc00:0:1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2405:fc00:0:1::123 0.129 0.277 0.422 3.103 11.255 57.454 170.776 10.834 57.177 11.197 5.241 ms 8.108 99.47

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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer jitter 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.177 0.282 0.431 1.896 9.440 14.838 110.847 9.009 14.556 7.600 3.789 ms 9.096 123

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 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu)

peer jitter 2607:f140:ffff:8000:0:8006:0:a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.127 0.220 0.371 1.827 10.125 15.758 136.181 9.754 15.538 7.271 3.679 ms 12.1 219.1

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 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com)

peer jitter 2a03:b0c0:1:d0::1f9:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.121 0.242 0.374 1.967 10.073 22.115 139.316 9.699 21.873 8.201 4.016 ms 9.859 155.7

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 76.14.161.109

peer jitter 76.14.161.109 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 76.14.161.109 0.763 1.176 1.663 8.923 37.130 50.520 171.784 35.466 49.344 14.674 13.829 ms 3.534 32.3

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) 1.327 4.310 5.801 11.067 22.120 28.936 82.853 16.319 24.626 5.194 12.150 ms 7.814 28.01

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 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) 47.000 98.000 132.000 250.000 481.000 608.000 862.000 349.000 510.000 108.252 270.460 ns 8.958 29.73

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 -5.884 -5.883 -5.872 -5.791 -5.622 -5.605 -5.603 0.250 0.277 0.072 -5.771 ppm -5.311e+05 4.302e+07
Local Clock Time Offset -1.543 -1.022 -0.775 0.004 0.625 0.839 1.235 1.400 1.861 0.427 -0.027 µs -4.635 11.72
Local RMS Frequency Jitter 27.000 36.000 44.000 84.000 186.000 218.000 330.000 142.000 182.000 44.747 96.008 10e-12 5.991 18.13
Local RMS Time Jitter 95.000 151.000 181.000 269.000 389.000 450.000 541.000 208.000 299.000 64.407 274.677 ns 45.1 187.4
Server Jitter 192.168.1.10 0.010 0.025 0.044 0.193 8.654 9.894 56.929 8.609 9.869 2.962 1.663 ms 2.116 33.8
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 0.000 0.182 0.328 1.664 9.719 33.958 102.748 9.391 33.775 8.718 3.836 ms 7.043 77.91
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.230 0.310 0.412 1.788 9.825 18.439 182.592 9.413 18.129 9.971 3.931 ms 10.34 157.4
Server Jitter 216.218.254.202 0.097 0.246 0.401 2.037 9.231 10.602 12.681 8.830 10.356 2.926 3.280 ms 1.576 3.926
Server Jitter 2405:fc00:0:1::123 0.129 0.277 0.422 3.103 11.255 57.454 170.776 10.834 57.177 11.197 5.241 ms 8.108 99.47
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.177 0.282 0.431 1.896 9.440 14.838 110.847 9.009 14.556 7.600 3.789 ms 9.096 123
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 0.127 0.220 0.371 1.827 10.125 15.758 136.181 9.754 15.538 7.271 3.679 ms 12.1 219.1
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.121 0.242 0.374 1.967 10.073 22.115 139.316 9.699 21.873 8.201 4.016 ms 9.859 155.7
Server Jitter 76.14.161.109 0.763 1.176 1.663 8.923 37.130 50.520 171.784 35.466 49.344 14.674 13.829 ms 3.534 32.3
Server Jitter SHM(0) 1.327 4.310 5.801 11.067 22.120 28.936 82.853 16.319 24.626 5.194 12.150 ms 7.814 28.01
Server Jitter SHM(1) 47.000 98.000 132.000 250.000 481.000 608.000 862.000 349.000 510.000 108.252 270.460 ns 8.958 29.73
Server Offset 192.168.1.10 -55.968 27.196 46.852 89.958 119.777 135.036 239.400 72.925 107.840 23.961 86.893 µs 25.42 88.03
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) -4.138 1.987 2.250 2.578 2.974 3.493 3.804 0.725 1.506 0.387 2.581 ms 189.5 1177
Server Offset 2001:470:e815::24 (pi4.rellim.com) 3.251 3.615 3.879 4.308 4.785 5.087 5.723 0.906 1.472 0.287 4.325 ms 2824 4.033e+04
Server Offset 216.218.254.202 0.891 2.070 2.231 2.545 2.898 3.176 3.295 0.666 1.106 0.229 2.557 ms 1087 1.138e+04
Server Offset 2405:fc00:0:1::123 8.643 8.913 9.173 9.634 10.598 10.905 11.330 1.425 1.992 0.431 9.735 ms 1.015e+04 2.208e+05
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) -10.191 -9.646 -4.123 2.055 3.748 4.154 4.740 7.870 13.799 2.371 1.748 ms -3.79 16.51
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) -0.055 1.997 2.210 2.506 2.880 3.118 3.368 0.671 1.120 0.231 2.521 ms 1004 1.023e+04
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) -8.812 -4.432 -0.935 2.932 6.240 11.089 12.709 7.174 15.521 2.395 2.749 ms 0.4971 6.406
Server Offset 76.14.161.109 -4.294 -2.580 -1.708 -0.581 0.892 2.550 5.602 2.600 5.130 0.921 -0.518 ms -7.374 22.42
Server Offset SHM(0) -472.314 -412.920 -399.115 -356.921 -312.846 -296.315 -252.124 86.270 116.605 26.192 -356.678 ms -3167 4.694e+04
Server Offset SHM(1) -1.544 -1.023 -0.776 0.005 0.625 0.840 1.236 1.401 1.863 0.428 -0.027 µs -4.634 11.71
TDOP 0.510 0.580 0.610 0.880 1.560 1.870 2.310 0.950 1.290 0.286 0.938 19.97 74.9
Temp ZONE0 60.148 60.148 60.686 62.300 63.376 63.376 63.914 2.690 3.228 0.740 62.091 °C
nSats 6.000 7.000 7.000 9.000 12.000 12.000 12.000 5.000 5.000 1.370 9.313 nSat 212.3 1334
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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