NTPsec

rabbit.wiktel.com

Report generated: Tue Dec 9 09:53:01 2025 UTC
Start Time: Mon Dec 8 09:53:01 2025 UTC
End Time: Tue Dec 9 09:53:01 2025 UTC
Report Period: 1.0 days

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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 -2.947 -1.500 -0.568 -0.025 0.735 1.623 3.253 1.303 3.123 0.448 0.010 µs -3.486 17.71
Local Clock Frequency Offset -17.658 -17.654 -17.583 -17.447 -17.336 -17.318 -17.302 0.247 0.336 0.075 -17.455 ppm -1.253e+07 2.909e+09

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 1.000 1.000 1.000 2.000 64.000 173.000 441.000 63.000 172.000 31.365 12.656 ns 3.046 25.69

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 0.002 0.006 0.011 0.088 1.062 1.738 2.845 1.051 1.732 0.367 0.239 ppb 1.658 8.601

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 -2.947 -1.500 -0.568 -0.025 0.735 1.623 3.253 1.303 3.123 0.448 0.010 µs -3.486 17.71

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 2600:2600::199 (ntp2.wiktel.com)

peer offset 2600:2600::199 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2600:2600::199 (ntp2.wiktel.com) 157.754 169.093 259.271 477.409 854.470 897.970 920.538 595.199 728.877 180.326 497.382 µs 11.24 34.4

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 2600:2600::99 (ntp1.wiktel.com)

peer offset 2600:2600::99 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2600:2600::99 (ntp1.wiktel.com) 0.539 0.562 0.628 0.846 1.236 1.290 1.331 0.609 0.728 0.182 0.873 ms 67.13 308

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 2602:fb95:16::123 (time5.sigi.net)

peer offset 2602:fb95:16::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2602:fb95:16::123 (time5.sigi.net) 1.845 1.849 1.922 2.279 2.802 2.872 2.949 0.880 1.023 0.238 2.288 ms 668.9 6012

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:a880:400:d0::4ed:f001 (unifi.versadns.com)

peer offset 2604:a880:400:d0::4ed:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2604:a880:400:d0::4ed:f001 (unifi.versadns.com) 2.454 2.536 2.633 2.964 3.714 3.870 4.016 1.080 1.334 0.312 3.001 ms 668.9 6026

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 2606:4700:f1::1 (time.cloudflare.com)

peer offset 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -1.880 -1.855 -1.770 -1.395 -1.008 -0.894 -0.888 0.762 0.961 0.249 -1.400 ms -310.4 2186

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 2606:4700:f1::123 (time.cloudflare.com)

peer offset 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -2.182 -2.125 -1.936 -1.610 -1.260 -1.149 -1.089 0.676 0.975 0.205 -1.594 ms -698.7 6355

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:f1c0:f06b:5000::3 (ntp11.kernfusion.at)

peer offset 2607:f1c0:f06b:5000::3 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:f1c0:f06b:5000::3 (ntp11.kernfusion.at) -1.457 -1.389 -1.323 -1.061 -0.710 -0.606 -0.548 0.612 0.783 0.189 -1.055 ms -304.2 2125

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) -2.948 -1.500 -0.569 -0.026 0.736 1.624 3.254 1.305 3.124 0.449 0.010 µs -3.488 17.68

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 2600:2600::199 (ntp2.wiktel.com)

peer jitter 2600:2600::199 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 9.313 13.307 21.161 51.702 119.352 150.824 260.191 98.191 137.517 30.787 59.116 µs 5.116 20.25

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 2600:2600::99 (ntp1.wiktel.com)

peer jitter 2600:2600::99 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 7.549 15.654 25.408 53.706 109.258 136.166 175.350 83.850 120.512 27.148 60.518 µs 6.388 19.28

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 2602:fb95:16::123 (time5.sigi.net)

peer jitter 2602:fb95:16::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2602:fb95:16::123 (time5.sigi.net) 15.246 20.906 28.595 58.928 141.441 208.442 246.262 112.846 187.536 36.983 67.483 µs 4.693 16.73

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.



Server Jitter 2604:a880:400:d0::4ed:f001 (unifi.versadns.com)

peer jitter 2604:a880:400:d0::4ed:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2604:a880:400:d0::4ed:f001 (unifi.versadns.com) 17.363 19.729 28.176 59.770 326.409 425.862 549.489 298.233 406.133 90.131 92.318 µs 2.541 9.131

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 2606:4700:f1::1 (time.cloudflare.com)

peer jitter 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 14.807 15.093 23.139 74.666 212.883 335.526 346.287 189.744 320.433 60.458 88.327 µs 3.276 11.46

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 2606:4700:f1::123 (time.cloudflare.com)

peer jitter 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 22.059 22.626 32.368 86.382 319.084 386.837 463.512 286.716 364.211 86.826 113.666 µs 2.631 8.184

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:f1c0:f06b:5000::3 (ntp11.kernfusion.at)

peer jitter 2607:f1c0:f06b:5000::3 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:f1c0:f06b:5000::3 (ntp11.kernfusion.at) 0.014 0.023 0.033 0.071 0.166 6.604 6.657 0.133 6.581 0.746 0.166 ms 5.721 51.41

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) 0.000 1.000 1.000 7.000 119.000 700.000 2,334.000 118.000 699.000 120.731 36.733 ns 5.501 63.15

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

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

RMS Jitter is field 8 in the peerstats log file.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -17.658 -17.654 -17.583 -17.447 -17.336 -17.318 -17.302 0.247 0.336 0.075 -17.455 ppm -1.253e+07 2.909e+09
Local Clock Time Offset -2.947 -1.500 -0.568 -0.025 0.735 1.623 3.253 1.303 3.123 0.448 0.010 µs -3.486 17.71
Local RMS Frequency Jitter 0.002 0.006 0.011 0.088 1.062 1.738 2.845 1.051 1.732 0.367 0.239 ppb 1.658 8.601
Local RMS Time Jitter 1.000 1.000 1.000 2.000 64.000 173.000 441.000 63.000 172.000 31.365 12.656 ns 3.046 25.69
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 9.313 13.307 21.161 51.702 119.352 150.824 260.191 98.191 137.517 30.787 59.116 µs 5.116 20.25
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 7.549 15.654 25.408 53.706 109.258 136.166 175.350 83.850 120.512 27.148 60.518 µs 6.388 19.28
Server Jitter 2602:fb95:16::123 (time5.sigi.net) 15.246 20.906 28.595 58.928 141.441 208.442 246.262 112.846 187.536 36.983 67.483 µs 4.693 16.73
Server Jitter 2604:a880:400:d0::4ed:f001 (unifi.versadns.com) 17.363 19.729 28.176 59.770 326.409 425.862 549.489 298.233 406.133 90.131 92.318 µs 2.541 9.131
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 14.807 15.093 23.139 74.666 212.883 335.526 346.287 189.744 320.433 60.458 88.327 µs 3.276 11.46
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 22.059 22.626 32.368 86.382 319.084 386.837 463.512 286.716 364.211 86.826 113.666 µs 2.631 8.184
Server Jitter 2607:f1c0:f06b:5000::3 (ntp11.kernfusion.at) 0.014 0.023 0.033 0.071 0.166 6.604 6.657 0.133 6.581 0.746 0.166 ms 5.721 51.41
Server Jitter SHM(0) 0.000 1.000 1.000 7.000 119.000 700.000 2,334.000 118.000 699.000 120.731 36.733 ns 5.501 63.15
Server Offset 2600:2600::199 (ntp2.wiktel.com) 157.754 169.093 259.271 477.409 854.470 897.970 920.538 595.199 728.877 180.326 497.382 µs 11.24 34.4
Server Offset 2600:2600::99 (ntp1.wiktel.com) 0.539 0.562 0.628 0.846 1.236 1.290 1.331 0.609 0.728 0.182 0.873 ms 67.13 308
Server Offset 2602:fb95:16::123 (time5.sigi.net) 1.845 1.849 1.922 2.279 2.802 2.872 2.949 0.880 1.023 0.238 2.288 ms 668.9 6012
Server Offset 2604:a880:400:d0::4ed:f001 (unifi.versadns.com) 2.454 2.536 2.633 2.964 3.714 3.870 4.016 1.080 1.334 0.312 3.001 ms 668.9 6026
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -1.880 -1.855 -1.770 -1.395 -1.008 -0.894 -0.888 0.762 0.961 0.249 -1.400 ms -310.4 2186
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -2.182 -2.125 -1.936 -1.610 -1.260 -1.149 -1.089 0.676 0.975 0.205 -1.594 ms -698.7 6355
Server Offset 2607:f1c0:f06b:5000::3 (ntp11.kernfusion.at) -1.457 -1.389 -1.323 -1.061 -0.710 -0.606 -0.548 0.612 0.783 0.189 -1.055 ms -304.2 2125
Server Offset SHM(0) -2.948 -1.500 -0.569 -0.026 0.736 1.624 3.254 1.305 3.124 0.449 0.010 µs -3.488 17.68
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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