NTPsec

chronos

Report generated: Mon Sep 26 00:05:02 2022 UTC
Start Time: Sun Sep 25 00:05:01 2022 UTC
End Time: Mon Sep 26 00:05:01 2022 UTC
Report Period: 1.0 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 -8.055 -2.542 -1.935 -0.591 1.798 18.038 49.586 3.733 20.580 3.300 -0.042 µs 2.978 44.94
Local Clock Frequency Offset -6.074 -6.073 -6.064 -5.830 -5.738 -5.709 -5.686 0.326 0.364 0.116 -5.872 ppm -1.369e+05 7.064e+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 0.238 0.279 0.327 0.531 4.345 8.346 14.348 4.018 8.067 1.539 1.050 µs 2.839 15.56

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 0.058 0.084 0.103 0.275 1.922 3.405 5.809 1.819 3.321 0.668 0.498 ppb 2.636 13.89

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 -8.055 -2.542 -1.935 -0.591 1.798 18.038 49.586 3.733 20.580 3.300 -0.042 µs 2.978 44.94

The clock offsets of the local clock as a histogram.

The Local Clock Offset is field 3 from the loopstats log file.



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 139.162.219.252

peer offset 139.162.219.252 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 139.162.219.252 -2.148 -2.011 -1.807 -1.243 -0.781 -0.214 0.012 1.026 1.797 0.345 -1.248 ms -112 580.8

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 162.159.200.123

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 -1.685 -1.323 -1.187 -0.907 -0.695 -0.657 -0.595 0.492 0.666 0.159 -0.919 ms -331 2397

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 178.32.55.184

peer offset 178.32.55.184 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 178.32.55.184 -1.742 -1.615 -1.437 -0.950 -0.499 -0.344 -0.264 0.938 1.271 0.284 -0.960 ms -97.63 490.5

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 195.171.43.12

peer offset 195.171.43.12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 195.171.43.12 -1.175 -1.092 -0.972 -0.604 -0.411 -0.380 -0.322 0.561 0.712 0.170 -0.634 ms -121.2 655.8

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 51.89.151.183

peer offset 51.89.151.183 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 51.89.151.183 -1.820 -1.692 -1.539 -1.215 -1.024 -0.970 -0.936 0.515 0.722 0.159 -1.240 ms -703.8 6436

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 81.21.65.169

peer offset 81.21.65.169 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 81.21.65.169 0.022 0.223 0.632 1.292 2.024 2.179 2.226 1.392 1.956 0.418 1.312 ms 16.12 50.45

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 82.219.4.30

peer offset 82.219.4.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 82.219.4.30 -1.935 -1.878 -1.756 -1.317 -0.893 -0.800 -0.656 0.864 1.079 0.265 -1.326 ms -233.5 1511

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) -50.558 -40.765 -36.647 -28.499 -25.399 -24.465 -22.282 11.249 16.300 3.189 -28.919 ms -1053 1.1e+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 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) -8.056 -2.543 -1.936 -0.592 1.799 18.039 49.587 3.735 20.582 3.300 -0.042 µs 2.975 44.93

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 139.162.219.252

peer jitter 139.162.219.252 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 139.162.219.252 0.102 0.173 0.301 0.524 0.858 1.667 2.148 0.556 1.494 0.260 0.567 ms 8.252 41.45

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 0.166 0.200 0.264 0.522 0.796 1.037 1.435 0.533 0.837 0.167 0.524 ms 16.99 62.76

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 178.32.55.184

peer jitter 178.32.55.184 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 178.32.55.184 0.195 0.213 0.272 0.527 0.753 1.745 2.794 0.480 1.532 0.237 0.539 ms 10.54 75

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 195.171.43.12

peer jitter 195.171.43.12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 195.171.43.12 125.186 161.423 249.648 522.602 788.674 982.123 3,555.568 539.026 820.700 247.560 526.855 µs 11.34 115.4

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 51.89.151.183

peer jitter 51.89.151.183 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 51.89.151.183 0.124 0.166 0.265 0.505 0.761 0.943 7.343 0.497 0.777 0.427 0.529 ms 14.54 233.8

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 81.21.65.169

peer jitter 81.21.65.169 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 81.21.65.169 0.143 0.213 0.282 0.528 0.822 1.531 4.838 0.540 1.318 0.317 0.556 ms 11.35 142.5

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 82.219.4.30

peer jitter 82.219.4.30 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 82.219.4.30 0.140 0.196 0.301 0.541 0.884 1.835 1.875 0.583 1.638 0.220 0.565 ms 11.33 53.43

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) 0.174 0.300 0.412 1.168 6.981 11.527 22.564 6.569 11.227 2.345 2.063 ms 2.65 14.97

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) 0.081 0.155 0.215 0.460 5.741 18.444 48.272 5.526 18.289 3.332 1.268 µs 3.831 34.5

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -6.074 -6.073 -6.064 -5.830 -5.738 -5.709 -5.686 0.326 0.364 0.116 -5.872 ppm -1.369e+05 7.064e+06
Local Clock Time Offset -8.055 -2.542 -1.935 -0.591 1.798 18.038 49.586 3.733 20.580 3.300 -0.042 µs 2.978 44.94
Local RMS Frequency Jitter 0.058 0.084 0.103 0.275 1.922 3.405 5.809 1.819 3.321 0.668 0.498 ppb 2.636 13.89
Local RMS Time Jitter 0.238 0.279 0.327 0.531 4.345 8.346 14.348 4.018 8.067 1.539 1.050 µs 2.839 15.56
Server Jitter 139.162.219.252 0.102 0.173 0.301 0.524 0.858 1.667 2.148 0.556 1.494 0.260 0.567 ms 8.252 41.45
Server Jitter 162.159.200.123 0.166 0.200 0.264 0.522 0.796 1.037 1.435 0.533 0.837 0.167 0.524 ms 16.99 62.76
Server Jitter 178.32.55.184 0.195 0.213 0.272 0.527 0.753 1.745 2.794 0.480 1.532 0.237 0.539 ms 10.54 75
Server Jitter 195.171.43.12 125.186 161.423 249.648 522.602 788.674 982.123 3,555.568 539.026 820.700 247.560 526.855 µs 11.34 115.4
Server Jitter 51.89.151.183 0.124 0.166 0.265 0.505 0.761 0.943 7.343 0.497 0.777 0.427 0.529 ms 14.54 233.8
Server Jitter 81.21.65.169 0.143 0.213 0.282 0.528 0.822 1.531 4.838 0.540 1.318 0.317 0.556 ms 11.35 142.5
Server Jitter 82.219.4.30 0.140 0.196 0.301 0.541 0.884 1.835 1.875 0.583 1.638 0.220 0.565 ms 11.33 53.43
Server Jitter SHM(0) 0.174 0.300 0.412 1.168 6.981 11.527 22.564 6.569 11.227 2.345 2.063 ms 2.65 14.97
Server Jitter SHM(1) 0.081 0.155 0.215 0.460 5.741 18.444 48.272 5.526 18.289 3.332 1.268 µs 3.831 34.5
Server Offset 139.162.219.252 -2.148 -2.011 -1.807 -1.243 -0.781 -0.214 0.012 1.026 1.797 0.345 -1.248 ms -112 580.8
Server Offset 162.159.200.123 -1.685 -1.323 -1.187 -0.907 -0.695 -0.657 -0.595 0.492 0.666 0.159 -0.919 ms -331 2397
Server Offset 178.32.55.184 -1.742 -1.615 -1.437 -0.950 -0.499 -0.344 -0.264 0.938 1.271 0.284 -0.960 ms -97.63 490.5
Server Offset 195.171.43.12 -1.175 -1.092 -0.972 -0.604 -0.411 -0.380 -0.322 0.561 0.712 0.170 -0.634 ms -121.2 655.8
Server Offset 51.89.151.183 -1.820 -1.692 -1.539 -1.215 -1.024 -0.970 -0.936 0.515 0.722 0.159 -1.240 ms -703.8 6436
Server Offset 81.21.65.169 0.022 0.223 0.632 1.292 2.024 2.179 2.226 1.392 1.956 0.418 1.312 ms 16.12 50.45
Server Offset 82.219.4.30 -1.935 -1.878 -1.756 -1.317 -0.893 -0.800 -0.656 0.864 1.079 0.265 -1.326 ms -233.5 1511
Server Offset SHM(0) -50.558 -40.765 -36.647 -28.499 -25.399 -24.465 -22.282 11.249 16.300 3.189 -28.919 ms -1053 1.1e+04
Server Offset SHM(1) -8.056 -2.543 -1.936 -0.592 1.799 18.039 49.587 3.735 20.582 3.300 -0.042 µs 2.975 44.93
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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