NTPsec

c-ntpsec-72-hour-stats

Report generated: Tue Apr 20 13:02:35 2021 UTC
Start Time: Sat Apr 17 13:02:33 2021 UTC
End Time: Tue Apr 20 13:02:33 2021 UTC
Report published: Tue Apr 20 06:02:48 2021 PDT
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 -1.593 -0.944 -0.696 0.031 0.746 1.013 2.363 1.442 1.957 0.449 0.025 µs -3.616 8.741
Local Clock Frequency Offset -5.332 -5.327 -5.251 -5.071 -4.941 -4.931 -4.929 0.310 0.396 0.095 -5.082 ppm -1.621e+05 8.848e+06

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 79.000 105.000 122.000 174.000 266.000 340.000 525.000 144.000 235.000 46.639 181.541 ns 34.21 142.1

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 24.000 35.000 45.000 104.000 237.000 322.000 516.000 192.000 287.000 60.759 116.142 10e-12 4.996 17.56

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 -1.593 -0.944 -0.696 0.031 0.746 1.013 2.363 1.442 1.957 0.449 0.025 µs -3.616 8.741

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 -5.332 -5.327 -5.251 -5.071 -4.941 -4.931 -4.929 0.310 0.396 0.095 -5.082 ppm -1.621e+05 8.848e+06
Temp ZONE0 55.844 56.382 56.920 58.534 60.686 61.224 61.762 3.766 4.842 1.176 58.676 °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 6.000 7.000 9.000 11.000 12.000 13.000 4.000 6.000 1.399 9.359 nSat 200.8 1237
TDOP 0.490 0.560 0.600 0.840 1.230 1.590 2.070 0.630 1.030 0.220 0.874 36.92 158.7

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. Smaller numbers are better. TDOP ranges from 1 (ideal), 2 to 5 (good), to greater than 20 (poor). Some GNSS receivers report TDOP less than one which is theoretically impossible.



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 1.351 1.492 1.674 2.124 2.611 3.354 4.878 0.937 1.862 0.344 2.138 ms 160.2 981.8

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

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

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

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



Server Offset 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 1.899 2.138 2.245 2.526 2.835 3.144 4.739 0.591 1.006 0.206 2.539 ms 1478 1.719e+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 162.159.200.123

peer offset 162.159.200.123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 162.159.200.123 1.476 2.153 2.319 2.585 2.923 3.277 3.633 0.604 1.124 0.201 2.598 ms 1726 2.1e+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 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 -1.607 -1.185 -0.492 0.254 0.814 1.377 2.367 1.306 2.562 0.426 0.229 ms -1.972 8.276

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 -3.061 -0.891 0.670 2.315 4.406 5.428 5.570 3.736 6.319 1.118 2.305 ms 4.241 13.03

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 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 -93.463 43.061 82.983 154.473 246.520 416.253 515.163 163.537 373.192 61.376 158.559 µs 10.58 42.78

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 194.58.202.211

peer offset 194.58.202.211 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 194.58.202.211 2.188 3.565 3.772 8.183 8.536 8.642 9.098 4.764 5.078 1.543 7.533 ms 68.35 293.8

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

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

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

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



Server Offset 194.58.202.219

peer offset 194.58.202.219 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 194.58.202.219 1.857 1.958 2.320 3.760 4.100 6.104 6.571 1.780 4.145 0.508 3.722 ms 271.5 1849

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 -33.660 -7.476 0.340 0.671 1.352 3.444 21.927 1.012 10.921 1.920 0.621 ms -9.891 203.9

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 204.123.2.5

peer offset 204.123.2.5 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.123.2.5 1.721 1.819 1.909 2.160 2.465 2.656 2.961 0.556 0.837 0.172 2.175 ms 1612 1.92e+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 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 2.777 3.102 3.243 3.539 3.875 4.140 4.439 0.632 1.037 0.198 3.548 ms 4882 8.341e+04

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

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

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

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



Server Offset SHM(0)

peer offset SHM(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(0) -68.577 -64.956 -62.800 -54.935 -46.991 -44.957 -43.403 15.809 19.999 4.735 -55.009 ms -2047 2.631e+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) -1.594 -0.945 -0.697 0.032 0.747 1.014 2.364 1.444 1.959 0.450 0.025 µs -3.617 8.736

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

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

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

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



Server 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 0.153 0.297 1.640 9.418 12.237 12.561 9.121 12.084 3.272 3.111 ms 1.209 3.205

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 0.114 0.158 0.259 1.499 8.929 12.465 15.317 8.670 12.306 2.876 2.676 ms 1.49 4.732

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 162.159.200.123

peer jitter 162.159.200.123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 162.159.200.123 0.113 0.165 0.258 1.181 8.975 12.687 48.142 8.717 12.522 3.536 2.675 ms 3.082 32.8

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 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 0.194 0.475 0.704 1.896 9.551 12.658 57.135 8.847 12.183 4.225 3.500 ms 5.432 61.99

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

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

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 178.62.68.79

peer jitter 178.62.68.79 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 178.62.68.79 0.269 0.299 0.527 1.631 8.574 36.354 77.012 8.046 36.055 6.716 3.395 ms 6.38 63.66

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 0.008 0.038 0.062 0.184 8.680 9.709 14.394 8.618 9.670 2.716 1.460 ms 0.6139 3.682

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 194.58.202.211

peer jitter 194.58.202.211 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 194.58.202.211 0.129 0.179 0.271 1.348 9.232 11.988 14.481 8.961 11.809 3.034 2.786 ms 1.238 3.775

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 194.58.202.219

peer jitter 194.58.202.219 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 194.58.202.219 0.143 0.197 0.309 1.676 9.449 12.973 17.966 9.140 12.776 3.238 3.215 ms 1.317 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 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 0.000 0.000 0.202 1.309 8.858 12.580 21.001 8.656 12.580 2.967 2.464 ms 1.516 6.089

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 204.123.2.5

peer jitter 204.123.2.5 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.123.2.5 0.169 0.187 0.279 1.446 8.805 10.273 72.220 8.527 10.086 4.219 2.657 ms 9.376 153.5

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 0.121 0.176 0.273 1.165 9.044 12.510 14.209 8.771 12.334 3.119 2.593 ms 1.103 3.61

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) 0.055 0.218 0.332 0.928 3.028 5.686 9.635 2.696 5.468 1.003 1.209 ms 3.416 15.8

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 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) 35.000 71.000 98.000 216.000 507.000 683.000 1,507.000 409.000 612.000 134.523 248.916 ns 4.937 20.07

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 -5.332 -5.327 -5.251 -5.071 -4.941 -4.931 -4.929 0.310 0.396 0.095 -5.082 ppm -1.621e+05 8.848e+06
Local Clock Time Offset -1.593 -0.944 -0.696 0.031 0.746 1.013 2.363 1.442 1.957 0.449 0.025 µs -3.616 8.741
Local RMS Frequency Jitter 24.000 35.000 45.000 104.000 237.000 322.000 516.000 192.000 287.000 60.759 116.142 10e-12 4.996 17.56
Local RMS Time Jitter 79.000 105.000 122.000 174.000 266.000 340.000 525.000 144.000 235.000 46.639 181.541 ns 34.21 142.1
Server Jitter 104.131.155.175 0.000 0.153 0.297 1.640 9.418 12.237 12.561 9.121 12.084 3.272 3.111 ms 1.209 3.205
Server Jitter 162.159.200.1 0.114 0.158 0.259 1.499 8.929 12.465 15.317 8.670 12.306 2.876 2.676 ms 1.49 4.732
Server Jitter 162.159.200.123 0.113 0.165 0.258 1.181 8.975 12.687 48.142 8.717 12.522 3.536 2.675 ms 3.082 32.8
Server Jitter 173.11.101.155 0.194 0.475 0.704 1.896 9.551 12.658 57.135 8.847 12.183 4.225 3.500 ms 5.432 61.99
Server Jitter 178.62.68.79 0.269 0.299 0.527 1.631 8.574 36.354 77.012 8.046 36.055 6.716 3.395 ms 6.38 63.66
Server Jitter 192.168.1.10 0.008 0.038 0.062 0.184 8.680 9.709 14.394 8.618 9.670 2.716 1.460 ms 0.6139 3.682
Server Jitter 194.58.202.211 0.129 0.179 0.271 1.348 9.232 11.988 14.481 8.961 11.809 3.034 2.786 ms 1.238 3.775
Server Jitter 194.58.202.219 0.143 0.197 0.309 1.676 9.449 12.973 17.966 9.140 12.776 3.238 3.215 ms 1.317 4
Server Jitter 203.123.48.219 0.000 0.000 0.202 1.309 8.858 12.580 21.001 8.656 12.580 2.967 2.464 ms 1.516 6.089
Server Jitter 204.123.2.5 0.169 0.187 0.279 1.446 8.805 10.273 72.220 8.527 10.086 4.219 2.657 ms 9.376 153.5
Server Jitter 204.17.205.24 0.121 0.176 0.273 1.165 9.044 12.510 14.209 8.771 12.334 3.119 2.593 ms 1.103 3.61
Server Jitter SHM(0) 0.055 0.218 0.332 0.928 3.028 5.686 9.635 2.696 5.468 1.003 1.209 ms 3.416 15.8
Server Jitter SHM(1) 35.000 71.000 98.000 216.000 507.000 683.000 1,507.000 409.000 612.000 134.523 248.916 ns 4.937 20.07
Server Offset 104.131.155.175 1.351 1.492 1.674 2.124 2.611 3.354 4.878 0.937 1.862 0.344 2.138 ms 160.2 981.8
Server Offset 162.159.200.1 1.899 2.138 2.245 2.526 2.835 3.144 4.739 0.591 1.006 0.206 2.539 ms 1478 1.719e+04
Server Offset 162.159.200.123 1.476 2.153 2.319 2.585 2.923 3.277 3.633 0.604 1.124 0.201 2.598 ms 1726 2.1e+04
Server Offset 173.11.101.155 -1.607 -1.185 -0.492 0.254 0.814 1.377 2.367 1.306 2.562 0.426 0.229 ms -1.972 8.276
Server Offset 178.62.68.79 -3.061 -0.891 0.670 2.315 4.406 5.428 5.570 3.736 6.319 1.118 2.305 ms 4.241 13.03
Server Offset 192.168.1.10 -93.463 43.061 82.983 154.473 246.520 416.253 515.163 163.537 373.192 61.376 158.559 µs 10.58 42.78
Server Offset 194.58.202.211 2.188 3.565 3.772 8.183 8.536 8.642 9.098 4.764 5.078 1.543 7.533 ms 68.35 293.8
Server Offset 194.58.202.219 1.857 1.958 2.320 3.760 4.100 6.104 6.571 1.780 4.145 0.508 3.722 ms 271.5 1849
Server Offset 203.123.48.219 -33.660 -7.476 0.340 0.671 1.352 3.444 21.927 1.012 10.921 1.920 0.621 ms -9.891 203.9
Server Offset 204.123.2.5 1.721 1.819 1.909 2.160 2.465 2.656 2.961 0.556 0.837 0.172 2.175 ms 1612 1.92e+04
Server Offset 204.17.205.24 2.777 3.102 3.243 3.539 3.875 4.140 4.439 0.632 1.037 0.198 3.548 ms 4882 8.341e+04
Server Offset SHM(0) -68.577 -64.956 -62.800 -54.935 -46.991 -44.957 -43.403 15.809 19.999 4.735 -55.009 ms -2047 2.631e+04
Server Offset SHM(1) -1.594 -0.945 -0.697 0.032 0.747 1.014 2.364 1.444 1.959 0.450 0.025 µs -3.617 8.736
TDOP 0.490 0.560 0.600 0.840 1.230 1.590 2.070 0.630 1.030 0.220 0.874 36.92 158.7
Temp ZONE0 55.844 56.382 56.920 58.534 60.686 61.224 61.762 3.766 4.842 1.176 58.676 °C
nSats 3.000 6.000 7.000 9.000 11.000 12.000 13.000 4.000 6.000 1.399 9.359 nSat 200.8 1237
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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