NTPsec

rabbit.wiktel.com

Report generated: Tue Dec 9 05:45:03 2025 UTC
Start Time: Tue Dec 2 05:45:02 2025 UTC
End Time: Tue Dec 9 05:45:02 2025 UTC
Report Period: 7.0 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 -2.945 -1.385 -0.615 0.010 0.535 1.162 3.254 1.150 2.547 0.378 0.001 µs -4.535 22.7
Local Clock Frequency Offset -17.869 -17.791 -17.743 -17.548 -17.370 -17.320 -17.104 0.373 0.471 0.121 -17.546 ppm -3.145e+06 4.608e+08

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 2.000 53.000 146.000 441.000 52.000 145.000 26.776 10.729 ns 3.229 28.12

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 0.001 0.006 0.009 0.074 0.884 1.468 2.845 0.875 1.462 0.311 0.200 ppb 1.707 9.559

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 -2.945 -1.385 -0.615 0.010 0.535 1.162 3.254 1.150 2.547 0.378 0.001 µs -4.535 22.7

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) -971.299 -813.716 -638.832 -91.145 589.595 854.470 926.031 1,228.427 1,668.186 372.958 -46.923 µs -4.543 10.72

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) -0.591 -0.402 -0.254 0.296 0.976 1.228 1.331 1.230 1.631 0.371 0.337 ms -0.05499 2.587

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) 0.752 0.894 1.099 1.700 2.371 2.773 2.949 1.272 1.878 0.381 1.740 ms 56.06 242.7

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) 0.082 0.656 1.155 2.121 3.852 6.226 7.071 2.697 5.570 0.928 2.252 ms 8.891 34.56

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) -2.629 -2.354 -2.110 -0.248 0.723 1.174 1.363 2.833 3.527 1.007 -0.646 ms -9.494 25.91

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 -1.936 -1.733 -0.194 0.323 0.404 0.474 2.056 2.340 0.647 -0.359 ms -9.592 30.76

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) -2.507 -2.343 -2.192 -1.626 -0.931 -0.674 -0.543 1.261 1.669 0.380 -1.592 ms -155.4 886.5

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 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) -2.946 -1.386 -0.616 0.011 0.536 1.163 3.255 1.152 2.549 0.378 0.001 µs -4.532 22.66

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) 7.056 16.737 22.880 52.837 116.929 156.984 304.862 94.049 140.247 30.694 58.988 µs 5.336 22.41

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 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 17.399 24.583 57.045 118.468 143.134 175.350 93.885 125.735 28.966 62.245 µs 5.811 17.07

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.



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) 10.586 19.181 28.814 59.105 134.036 205.810 1,727.184 105.222 186.629 88.099 71.600 µs 14.07 247.3

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

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

RMS Jitter is field 8 in the peerstats log file.



Server Jitter 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) 0.014 0.022 0.031 0.072 0.356 0.778 9.689 0.324 0.756 0.329 0.126 ms 17.67 440.8

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 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) 0.011 0.020 0.029 0.072 0.209 0.363 52.207 0.181 0.343 3.229 0.313 ms 11.04 165.8

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 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) 16.030 20.896 29.274 76.794 322.624 422.175 504.641 293.350 401.279 88.392 107.129 µs 2.608 8.606

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) 0.009 0.022 0.032 0.066 0.147 0.249 6.657 0.115 0.227 0.295 0.090 ms 18.75 410.9

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 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 6.000 99.000 588.000 2,334.000 98.000 587.000 103.179 30.929 ns 5.725 67.87

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 -17.869 -17.791 -17.743 -17.548 -17.370 -17.320 -17.104 0.373 0.471 0.121 -17.546 ppm -3.145e+06 4.608e+08
Local Clock Time Offset -2.945 -1.385 -0.615 0.010 0.535 1.162 3.254 1.150 2.547 0.378 0.001 µs -4.535 22.7
Local RMS Frequency Jitter 0.001 0.006 0.009 0.074 0.884 1.468 2.845 0.875 1.462 0.311 0.200 ppb 1.707 9.559
Local RMS Time Jitter 0.000 1.000 1.000 2.000 53.000 146.000 441.000 52.000 145.000 26.776 10.729 ns 3.229 28.12
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 7.056 16.737 22.880 52.837 116.929 156.984 304.862 94.049 140.247 30.694 58.988 µs 5.336 22.41
Server Jitter 2600:2600::99 (ntp1.wiktel.com) 7.549 17.399 24.583 57.045 118.468 143.134 175.350 93.885 125.735 28.966 62.245 µs 5.811 17.07
Server Jitter 2602:fb95:16::123 (time5.sigi.net) 10.586 19.181 28.814 59.105 134.036 205.810 1,727.184 105.222 186.629 88.099 71.600 µs 14.07 247.3
Server Jitter 2604:a880:400:d0::4ed:f001 (unifi.versadns.com) 0.014 0.022 0.031 0.072 0.356 0.778 9.689 0.324 0.756 0.329 0.126 ms 17.67 440.8
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 0.011 0.020 0.029 0.072 0.209 0.363 52.207 0.181 0.343 3.229 0.313 ms 11.04 165.8
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 16.030 20.896 29.274 76.794 322.624 422.175 504.641 293.350 401.279 88.392 107.129 µs 2.608 8.606
Server Jitter 2607:f1c0:f06b:5000::3 (ntp11.kernfusion.at) 0.009 0.022 0.032 0.066 0.147 0.249 6.657 0.115 0.227 0.295 0.090 ms 18.75 410.9
Server Jitter SHM(0) 0.000 1.000 1.000 6.000 99.000 588.000 2,334.000 98.000 587.000 103.179 30.929 ns 5.725 67.87
Server Offset 2600:2600::199 (ntp2.wiktel.com) -971.299 -813.716 -638.832 -91.145 589.595 854.470 926.031 1,228.427 1,668.186 372.958 -46.923 µs -4.543 10.72
Server Offset 2600:2600::99 (ntp1.wiktel.com) -0.591 -0.402 -0.254 0.296 0.976 1.228 1.331 1.230 1.631 0.371 0.337 ms -0.05499 2.587
Server Offset 2602:fb95:16::123 (time5.sigi.net) 0.752 0.894 1.099 1.700 2.371 2.773 2.949 1.272 1.878 0.381 1.740 ms 56.06 242.7
Server Offset 2604:a880:400:d0::4ed:f001 (unifi.versadns.com) 0.082 0.656 1.155 2.121 3.852 6.226 7.071 2.697 5.570 0.928 2.252 ms 8.891 34.56
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -2.629 -2.354 -2.110 -0.248 0.723 1.174 1.363 2.833 3.527 1.007 -0.646 ms -9.494 25.91
Server Offset 2606:4700:f1::123 (time.cloudflare.com) -2.182 -1.936 -1.733 -0.194 0.323 0.404 0.474 2.056 2.340 0.647 -0.359 ms -9.592 30.76
Server Offset 2607:f1c0:f06b:5000::3 (ntp11.kernfusion.at) -2.507 -2.343 -2.192 -1.626 -0.931 -0.674 -0.543 1.261 1.669 0.380 -1.592 ms -155.4 886.5
Server Offset SHM(0) -2.946 -1.386 -0.616 0.011 0.536 1.163 3.255 1.152 2.549 0.378 0.001 µs -4.532 22.66
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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