NTPsec

crane3.services.mbix.ca

Report generated: Wed Sep 16 04:45:02 2026 UTC
Start Time: Wed Sep 9 04:45:01 2026 UTC
End Time: Wed Sep 16 04:45:01 2026 UTC
Report Period: 7.0 days

Top   Daily Stats   Weekly Stats  

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 -57.267 -23.507 -17.684 -3.229 28.595 40.003 75.751 46.279 63.510 14.004 -0.003 µs -3.032 6.967
Local Clock Frequency Offset 78.185 78.464 78.569 78.670 78.746 78.777 78.829 0.177 0.314 0.062 78.663 ppm 2.005e+09 2.528e+12

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 5.262 9.144 11.144 18.242 26.833 30.751 43.511 15.689 21.607 4.812 18.500 µs 31.92 121.2

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 2.099 3.438 4.147 6.594 9.336 10.696 16.984 5.189 7.258 1.607 6.647 ppb 40.64 164.3

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 -57.267 -23.507 -17.684 -3.229 28.595 40.003 75.751 46.279 63.510 14.004 -0.003 µs -3.032 6.967

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 78.185 78.464 78.569 78.670 78.746 78.777 78.829 0.177 0.314 0.062 78.663 ppm 2.005e+09 2.528e+12
Temp LM0 37.000 37.000 38.000 40.000 41.000 42.000 42.000 3.000 5.000 0.927 39.667 °C
Temp LM1 34.000 35.000 35.000 36.000 38.000 39.000 39.000 3.000 4.000 0.949 36.372 °C
Temp LM10 31.000 33.000 33.000 35.000 37.000 38.000 39.000 4.000 5.000 1.135 35.369 °C
Temp LM2 32.000 32.000 33.000 34.000 36.000 36.000 39.000 3.000 4.000 0.895 34.204 °C
Temp LM3 37.000 37.000 38.000 40.000 41.000 42.000 42.000 3.000 5.000 0.934 39.660 °C
Temp LM4 34.000 35.000 35.000 36.000 37.000 38.000 40.000 2.000 3.000 0.777 35.939 °C
Temp LM5 61.000 62.000 63.000 63.000 64.000 64.000 64.000 1.000 2.000 0.550 63.361 °C
Temp LM6 39.000 40.000 41.000 42.000 43.000 44.000 46.000 2.000 4.000 0.902 42.292 °C
Temp LM7 38.000 39.000 39.000 41.000 43.000 43.000 44.000 4.000 4.000 1.023 41.076 °C
Temp LM8 38.000 40.000 40.000 42.000 43.000 44.000 46.000 3.000 4.000 0.917 41.904 °C
Temp LM9 36.000 37.000 38.000 40.000 42.000 43.000 43.000 4.000 6.000 1.101 39.723 °C
Temp ZONE0 39.000 40.000 41.000 43.000 44.000 44.000 45.000 3.000 4.000 0.975 42.425 °C
Temp ZONE1 36.000 37.000 38.000 40.000 41.000 42.000 43.000 3.000 5.000 1.010 39.747 °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.



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 132.246.11.227

peer offset 132.246.11.227 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 132.246.11.227 1.250 1.953 1.995 2.084 2.171 2.210 2.281 0.176 0.258 0.067 2.082 ms 2.721e+04 8.198e+05

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 142.3.100.2

peer offset 142.3.100.2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 142.3.100.2 -134.116 -0.058 -0.041 -0.001 0.043 0.067 0.126 0.084 0.125 4.224 -0.189 ms -30.12 828.9

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 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) 309.471 333.706 343.977 371.689 404.053 416.373 432.934 60.076 82.667 18.023 372.444 µs 7663 1.519e+05

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:fde5:2a::13 (ntp3.torix.ca)

peer offset 2602:fde5:2a::13 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2602:fde5:2a::13 (ntp3.torix.ca) 1.216 1.455 1.468 1.497 2.080 2.097 2.120 0.612 0.642 0.253 1.641 ms 182.8 1114

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) -2.213 -1.236 -0.905 -0.275 0.238 0.395 0.546 1.144 1.631 0.352 -0.293 ms -12.3 40.5

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 2607:f388::123:1 (ntp1.doit.wisc.edu)

peer offset 2607:f388::123:1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:f388::123:1 (ntp1.doit.wisc.edu) -0.866 -0.443 -0.353 0.961 4.544 6.807 10.619 4.897 7.250 1.564 1.319 ms 1.198 6.155

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 PPS(0)

peer offset PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset PPS(0) -57.268 -23.508 -17.685 -3.230 28.596 40.004 75.752 46.281 63.512 14.005 -0.004 µs -3.032 6.967

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 132.246.11.227

peer jitter 132.246.11.227 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 132.246.11.227 0.033 0.052 0.073 0.314 2.224 5.205 112.581 2.152 5.153 6.052 0.959 ms 11.8 194.7

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 142.3.100.2

peer jitter 142.3.100.2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 142.3.100.2 0.009 0.015 0.021 0.041 0.107 26.795 269.262 0.086 26.780 16.208 1.503 ms 9.955 151.1

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) 3.563 7.503 10.116 20.078 42.029 58.890 332.150 31.913 51.387 15.874 22.838 µs 12.61 226.3

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 2602:fde5:2a::13 (ntp3.torix.ca)

peer jitter 2602:fde5:2a::13 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2602:fde5:2a::13 (ntp3.torix.ca) 4.806 7.591 11.539 316.287 577.546 593.958 671.607 566.007 586.367 234.339 270.988 µs 0.4831 1.355

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) 8.036 15.780 22.956 70.353 241.164 448.301 1,228.836 218.208 432.521 89.176 95.196 µs 4.105 30.42

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:f388::123:1 (ntp1.doit.wisc.edu)

peer jitter 2607:f388::123:1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:f388::123:1 (ntp1.doit.wisc.edu) 2.112 3.993 6.057 12.548 23.855 29.883 37.164 17.797 25.889 5.528 13.483 ms 8.158 25.59

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 PPS(0)

peer jitter PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter PPS(0) 1.634 5.023 7.150 17.020 34.719 44.871 79.539 27.569 39.848 8.580 18.419 µs 6.029 19.41

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset 78.185 78.464 78.569 78.670 78.746 78.777 78.829 0.177 0.314 0.062 78.663 ppm 2.005e+09 2.528e+12
Local Clock Time Offset -57.267 -23.507 -17.684 -3.229 28.595 40.003 75.751 46.279 63.510 14.004 -0.003 µs -3.032 6.967
Local RMS Frequency Jitter 2.099 3.438 4.147 6.594 9.336 10.696 16.984 5.189 7.258 1.607 6.647 ppb 40.64 164.3
Local RMS Time Jitter 5.262 9.144 11.144 18.242 26.833 30.751 43.511 15.689 21.607 4.812 18.500 µs 31.92 121.2
Server Jitter 132.246.11.227 0.033 0.052 0.073 0.314 2.224 5.205 112.581 2.152 5.153 6.052 0.959 ms 11.8 194.7
Server Jitter 142.3.100.2 0.009 0.015 0.021 0.041 0.107 26.795 269.262 0.086 26.780 16.208 1.503 ms 9.955 151.1
Server Jitter 2600:2600::199 (ntp2.wiktel.com) 3.563 7.503 10.116 20.078 42.029 58.890 332.150 31.913 51.387 15.874 22.838 µs 12.61 226.3
Server Jitter 2602:fde5:2a::13 (ntp3.torix.ca) 4.806 7.591 11.539 316.287 577.546 593.958 671.607 566.007 586.367 234.339 270.988 µs 0.4831 1.355
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 8.036 15.780 22.956 70.353 241.164 448.301 1,228.836 218.208 432.521 89.176 95.196 µs 4.105 30.42
Server Jitter 2607:f388::123:1 (ntp1.doit.wisc.edu) 2.112 3.993 6.057 12.548 23.855 29.883 37.164 17.797 25.889 5.528 13.483 ms 8.158 25.59
Server Jitter PPS(0) 1.634 5.023 7.150 17.020 34.719 44.871 79.539 27.569 39.848 8.580 18.419 µs 6.029 19.41
Server Offset 132.246.11.227 1.250 1.953 1.995 2.084 2.171 2.210 2.281 0.176 0.258 0.067 2.082 ms 2.721e+04 8.198e+05
Server Offset 142.3.100.2 -134.116 -0.058 -0.041 -0.001 0.043 0.067 0.126 0.084 0.125 4.224 -0.189 ms -30.12 828.9
Server Offset 2600:2600::199 (ntp2.wiktel.com) 309.471 333.706 343.977 371.689 404.053 416.373 432.934 60.076 82.667 18.023 372.444 µs 7663 1.519e+05
Server Offset 2602:fde5:2a::13 (ntp3.torix.ca) 1.216 1.455 1.468 1.497 2.080 2.097 2.120 0.612 0.642 0.253 1.641 ms 182.8 1114
Server Offset 2606:4700:f1::1 (time.cloudflare.com) -2.213 -1.236 -0.905 -0.275 0.238 0.395 0.546 1.144 1.631 0.352 -0.293 ms -12.3 40.5
Server Offset 2607:f388::123:1 (ntp1.doit.wisc.edu) -0.866 -0.443 -0.353 0.961 4.544 6.807 10.619 4.897 7.250 1.564 1.319 ms 1.198 6.155
Server Offset PPS(0) -57.268 -23.508 -17.685 -3.230 28.596 40.004 75.752 46.281 63.512 14.005 -0.004 µs -3.032 6.967
Temp LM0 37.000 37.000 38.000 40.000 41.000 42.000 42.000 3.000 5.000 0.927 39.667 °C
Temp LM1 34.000 35.000 35.000 36.000 38.000 39.000 39.000 3.000 4.000 0.949 36.372 °C
Temp LM10 31.000 33.000 33.000 35.000 37.000 38.000 39.000 4.000 5.000 1.135 35.369 °C
Temp LM2 32.000 32.000 33.000 34.000 36.000 36.000 39.000 3.000 4.000 0.895 34.204 °C
Temp LM3 37.000 37.000 38.000 40.000 41.000 42.000 42.000 3.000 5.000 0.934 39.660 °C
Temp LM4 34.000 35.000 35.000 36.000 37.000 38.000 40.000 2.000 3.000 0.777 35.939 °C
Temp LM5 61.000 62.000 63.000 63.000 64.000 64.000 64.000 1.000 2.000 0.550 63.361 °C
Temp LM6 39.000 40.000 41.000 42.000 43.000 44.000 46.000 2.000 4.000 0.902 42.292 °C
Temp LM7 38.000 39.000 39.000 41.000 43.000 43.000 44.000 4.000 4.000 1.023 41.076 °C
Temp LM8 38.000 40.000 40.000 42.000 43.000 44.000 46.000 3.000 4.000 0.917 41.904 °C
Temp LM9 36.000 37.000 38.000 40.000 42.000 43.000 43.000 4.000 6.000 1.101 39.723 °C
Temp ZONE0 39.000 40.000 41.000 43.000 44.000 44.000 45.000 3.000 4.000 0.975 42.425 °C
Temp ZONE1 36.000 37.000 38.000 40.000 41.000 42.000 43.000 3.000 5.000 1.010 39.747 °C
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.



This page autogenerated by ntpviz, part of the NTPsec project
html 5    Valid CSS!