NTPsec

rabbit.wiktel.com

Report generated: Thu Aug 6 16:53:02 2026 UTC
Start Time: Wed Aug 5 16:53:02 2026 UTC
End Time: Thu Aug 6 16:53:02 2026 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 -890.000 -416.000 -179.000 0.000 173.000 560.000 1,029.000 352.000 976.000 134.331 -0.999 ns -3.125 19.47
Local Clock Frequency Offset -20.638 -20.634 -20.624 -20.573 -20.510 -20.503 -20.500 0.114 0.131 0.034 -20.569 ppm -2.304e+08 1.412e+11

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 0.000 1.000 1.000 1.000 14.000 51.000 124.000 13.000 50.000 9.061 3.610 ns 4.219 38.63

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 0.000 3.000 7.000 24.000 320.000 581.000 897.000 313.000 578.000 112.910 67.995 10e-12 1.967 10.59

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 -890.000 -416.000 -179.000 0.000 173.000 560.000 1,029.000 352.000 976.000 134.331 -0.999 ns -3.125 19.47

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 198.23.132.33

peer offset 198.23.132.33 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 198.23.132.33 -6.337 -6.303 -6.147 -1.949 -1.138 -0.999 -0.851 5.009 5.304 2.208 -3.475 ms -24.92 86.22

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 23.157.100.123

peer offset 23.157.100.123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 23.157.100.123 0.992 1.019 1.092 1.668 2.195 2.246 2.294 1.103 1.227 0.322 1.649 ms 82.43 393

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::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) -634.505 -599.181 -559.107 -271.675 -3.305 40.238 86.465 555.802 639.419 174.253 -280.710 µs -25.76 90.79

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) -263.461 -249.875 -180.706 99.678 354.288 409.414 447.285 534.994 659.289 175.248 92.293 µs -1.685 3.647

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) -449.524 -395.799 -283.328 19.929 342.260 406.840 521.237 625.588 802.639 186.488 16.987 µs -3.434 8.201

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 45.63.54.13

peer offset 45.63.54.13 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 45.63.54.13 -6.392 -6.352 -6.310 -2.008 -1.350 -1.149 -1.084 4.960 5.203 2.144 -3.656 ms -28.05 99.99

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) -891.000 -417.000 -180.000 1.000 174.000 561.000 1,030.000 354.000 978.000 134.813 -0.977 ns -3.131 19.37

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 198.23.132.33

peer jitter 198.23.132.33 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 198.23.132.33 21.858 23.811 37.729 86.805 344.334 499.686 4,231.425 306.605 475.875 253.344 139.699 µs 11.9 189.9

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 23.157.100.123

peer jitter 23.157.100.123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 23.157.100.123 0.018 0.021 0.033 0.064 0.126 4.365 13.784 0.092 4.344 1.157 0.213 ms 6.124 66.09

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::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) 16.828 23.021 31.142 55.503 103.170 125.764 136.516 72.028 102.743 22.625 59.855 µs 10.24 32.66

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 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) 18.840 21.100 31.806 59.147 110.526 128.990 166.184 78.720 107.890 23.884 63.819 µs 10.5 33.85

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) 18.082 24.902 35.129 83.341 340.722 442.682 547.483 305.593 417.780 98.791 121.225 µs 2.438 7.603

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 45.63.54.13

peer jitter 45.63.54.13 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 45.63.54.13 0.021 0.023 0.034 0.065 0.383 3.815 4.221 0.349 3.792 0.528 0.180 ms 4.149 30.55

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 0.000 1.000 2.000 34.000 164.000 648.000 33.000 164.000 34.696 9.671 ns 6.9 88.82

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 -20.638 -20.634 -20.624 -20.573 -20.510 -20.503 -20.500 0.114 0.131 0.034 -20.569 ppm -2.304e+08 1.412e+11
Local Clock Time Offset -890.000 -416.000 -179.000 0.000 173.000 560.000 1,029.000 352.000 976.000 134.331 -0.999 ns -3.125 19.47
Local RMS Frequency Jitter 0.000 3.000 7.000 24.000 320.000 581.000 897.000 313.000 578.000 112.910 67.995 10e-12 1.967 10.59
Local RMS Time Jitter 0.000 1.000 1.000 1.000 14.000 51.000 124.000 13.000 50.000 9.061 3.610 ns 4.219 38.63
Server Jitter 198.23.132.33 21.858 23.811 37.729 86.805 344.334 499.686 4,231.425 306.605 475.875 253.344 139.699 µs 11.9 189.9
Server Jitter 23.157.100.123 0.018 0.021 0.033 0.064 0.126 4.365 13.784 0.092 4.344 1.157 0.213 ms 6.124 66.09
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 16.828 23.021 31.142 55.503 103.170 125.764 136.516 72.028 102.743 22.625 59.855 µs 10.24 32.66
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 18.840 21.100 31.806 59.147 110.526 128.990 166.184 78.720 107.890 23.884 63.819 µs 10.5 33.85
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 18.082 24.902 35.129 83.341 340.722 442.682 547.483 305.593 417.780 98.791 121.225 µs 2.438 7.603
Server Jitter 45.63.54.13 0.021 0.023 0.034 0.065 0.383 3.815 4.221 0.349 3.792 0.528 0.180 ms 4.149 30.55
Server Jitter SHM(0) 0.000 0.000 1.000 2.000 34.000 164.000 648.000 33.000 164.000 34.696 9.671 ns 6.9 88.82
Server Offset 198.23.132.33 -6.337 -6.303 -6.147 -1.949 -1.138 -0.999 -0.851 5.009 5.304 2.208 -3.475 ms -24.92 86.22
Server Offset 23.157.100.123 0.992 1.019 1.092 1.668 2.195 2.246 2.294 1.103 1.227 0.322 1.649 ms 82.43 393
Server Offset 2600:2600::199 (ntp2.wiktel.com) -634.505 -599.181 -559.107 -271.675 -3.305 40.238 86.465 555.802 639.419 174.253 -280.710 µs -25.76 90.79
Server Offset 2600:2600::99 (ntp1.wiktel.com) -263.461 -249.875 -180.706 99.678 354.288 409.414 447.285 534.994 659.289 175.248 92.293 µs -1.685 3.647
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -449.524 -395.799 -283.328 19.929 342.260 406.840 521.237 625.588 802.639 186.488 16.987 µs -3.434 8.201
Server Offset 45.63.54.13 -6.392 -6.352 -6.310 -2.008 -1.350 -1.149 -1.084 4.960 5.203 2.144 -3.656 ms -28.05 99.99
Server Offset SHM(0) -891.000 -417.000 -180.000 1.000 174.000 561.000 1,030.000 354.000 978.000 134.813 -0.977 ns -3.131 19.37
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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