NTPsec

A-ntpsec-6-hour-stats

Report generated: Sun Jul 3 08:02:30 2022 UTC
Start Time: Sun Jul 3 02:02:30 2022 UTC
End Time: Sun Jul 3 08:02:30 2022 UTC
Report published: Sun Jul 03 01:02:36 2022 PDT
Report Period: 0.2 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 -1.412 -1.016 -0.705 0.001 0.651 0.955 1.298 1.356 1.971 0.411 -0.005 µs -4.141 10.51
Local Clock Frequency Offset -35.950 -35.751 -35.522 -32.059 -26.474 -26.062 -25.848 9.048 9.689 2.757 -31.871 ppb -2019 2.582e+04

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 260.000 306.000 363.000 538.000 733.000 822.000 966.000 370.000 516.000 110.360 541.381 ns 71.55 331.3

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 54.000 62.000 70.000 98.000 133.000 156.000 175.000 63.000 94.000 19.336 99.237 10e-12 83.59 408.3

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 -1.412 -1.016 -0.705 0.001 0.651 0.955 1.298 1.356 1.971 0.411 -0.005 µs -4.141 10.51

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 -35.950 -35.751 -35.522 -32.059 -26.474 -26.062 -25.848 9.048 9.689 2.757 -31.871 ppb -2019 2.582e+04
Temp ZONE0 54.768 54.768 55.306 55.844 56.382 56.382 56.920 1.076 1.614 0.348 55.847 °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.



Local GPS

local gps plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
nSats 6.000 7.000 7.000 9.000 11.000 12.000 12.000 4.000 5.000 1.126 9.273 nSat 400.2 3052
TDOP 0.490 0.500 0.550 0.810 1.460 1.490 1.870 0.910 0.990 0.259 0.865 20.85 77.28

Local GPS. The Time Dilution of Precision (TDOP) is plotted in blue. The number of visible satellites (nSat) is plotted in red.

TDOP is field 3, and nSats is field 4, from the gpsd log file. The gpsd log file is created by the ntploggps program.

TDOP is a dimensionless error factor. Smaller numbers are better. TDOP ranges from 1 (ideal), 2 to 5 (good), to greater than 20 (poor). Some GNSS receivers report TDOP less than one which is theoretically impossible.



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 104.131.155.175

peer offset 104.131.155.175 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 104.131.155.175 2.658 2.658 2.889 3.389 4.028 4.259 4.259 1.138 1.601 0.416 3.478 ms 422 3275

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 162.159.200.1

peer offset 162.159.200.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 162.159.200.1 4.463 4.463 4.691 5.070 5.587 5.762 5.762 0.896 1.299 0.288 5.112 ms 4726 7.988e+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 169.229.128.134

peer offset 169.229.128.134 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 169.229.128.134 2.039 2.039 2.132 2.396 2.697 2.810 2.810 0.565 0.771 0.189 2.397 ms 1621 1.932e+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 173.11.101.155

peer offset 173.11.101.155 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 173.11.101.155 -1.628 -1.628 -1.232 -0.085 0.922 1.483 1.483 2.154 3.111 0.614 -0.142 ms -5.564 15.05

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 178.62.68.79

peer offset 178.62.68.79 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 178.62.68.79 -2.970 -2.970 -2.970 1.242 10.581 10.581 10.581 13.551 13.551 2.573 1.501 ms 0.6231 6.735

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 192.168.1.11

peer offset 192.168.1.11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.11 -515.749 -473.818 -347.486 -78.736 70.357 153.292 276.283 417.843 627.110 119.117 -94.947 µs -12.06 40.66

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 Offset 204.17.205.23

peer offset 204.17.205.23 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.23 0.864 0.864 0.995 1.446 2.475 2.475 2.475 1.480 1.611 0.485 1.538 ms 17.27 57.31

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 216.218.192.202

peer offset 216.218.192.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 216.218.192.202 1.859 1.859 2.097 2.436 2.900 3.361 3.361 0.803 1.502 0.247 2.431 ms 718.7 6619

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 216.218.254.202

peer offset 216.218.254.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 216.218.254.202 1.777 1.777 1.867 2.348 2.739 3.088 3.088 0.872 1.311 0.266 2.340 ms 500.4 4097

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 45.33.37.82

peer offset 45.33.37.82 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 45.33.37.82 1.733 1.733 2.334 2.906 3.633 4.141 4.141 1.299 2.408 0.389 2.917 ms 294.8 2051

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 91.200.61.123

peer offset 91.200.61.123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 91.200.61.123 0.392 0.392 0.433 0.927 1.564 1.564 1.564 1.131 1.172 0.305 0.901 ms 13.63 42.66

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 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) -55.569 -53.983 -52.908 -48.723 -44.495 -42.121 -40.830 8.414 11.862 2.517 -48.861 ms -8566 1.761e+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 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) -1.413 -1.017 -0.706 0.002 0.652 0.956 1.299 1.358 1.973 0.412 -0.005 µs -4.14 10.5

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 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 104.131.155.175

peer jitter 104.131.155.175 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 104.131.155.175 0.576 0.576 0.734 1.489 54.779 54.790 54.790 54.044 54.214 18.651 8.996 ms 0.3469 2.62

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 162.159.200.1

peer jitter 162.159.200.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 162.159.200.1 0.326 0.326 0.513 1.153 6.848 13.356 13.356 6.335 13.030 2.469 2.102 ms 2.16 8.759

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 169.229.128.134

peer jitter 169.229.128.134 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 169.229.128.134 0.191 0.191 0.366 1.068 11.823 30.441 30.441 11.457 30.251 4.293 2.271 ms 3.214 21.12

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 173.11.101.155

peer jitter 173.11.101.155 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 173.11.101.155 0.893 0.893 0.946 1.734 12.048 12.533 12.533 11.102 11.640 2.494 2.483 ms 3.287 13.03

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 178.62.68.79

peer jitter 178.62.68.79 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 178.62.68.79 0.524 0.524 0.524 1.408 145.303 145.303 145.303 144.779 144.779 50.829 24.136 ms 0.1536 2.317

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 192.168.1.11

peer jitter 192.168.1.11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.11 0.000 0.068 0.124 0.549 6.028 12.199 13.496 5.904 12.132 2.129 1.145 ms 2.417 12.74

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 204.17.205.23

peer jitter 204.17.205.23 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.23 0.000 0.000 0.313 1.487 11.124 11.124 11.124 10.811 11.124 3.707 3.038 ms 0.9466 2.603

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 216.218.192.202

peer jitter 216.218.192.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 216.218.192.202 0.412 0.412 0.540 1.416 9.915 49.639 49.639 9.375 49.227 6.791 2.928 ms 3.986 28.25

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 216.218.254.202

peer jitter 216.218.254.202 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 216.218.254.202 0.231 0.231 0.406 1.130 12.265 15.168 15.168 11.859 14.937 3.888 2.679 ms 1.326 4.586

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 45.33.37.82

peer jitter 45.33.37.82 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 45.33.37.82 0.250 0.250 0.466 1.260 14.092 135.466 135.466 13.626 135.215 26.064 7.100 ms 2.092 12.82

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.



Server Jitter 91.200.61.123

peer jitter 91.200.61.123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 91.200.61.123 0.501 0.501 0.758 1.396 47.946 47.946 47.946 47.188 47.445 10.441 5.616 ms 1.822 8.767

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) 0.069 0.171 0.316 0.928 2.223 3.150 5.104 1.907 2.979 0.614 1.054 ms 4.045 14.56

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) 0.138 0.199 0.266 0.503 0.938 1.188 1.748 0.672 0.989 0.211 0.543 µs 9.83 33.59

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -35.950 -35.751 -35.522 -32.059 -26.474 -26.062 -25.848 9.048 9.689 2.757 -31.871 ppb -2019 2.582e+04
Local Clock Time Offset -1.412 -1.016 -0.705 0.001 0.651 0.955 1.298 1.356 1.971 0.411 -0.005 µs -4.141 10.51
Local RMS Frequency Jitter 54.000 62.000 70.000 98.000 133.000 156.000 175.000 63.000 94.000 19.336 99.237 10e-12 83.59 408.3
Local RMS Time Jitter 260.000 306.000 363.000 538.000 733.000 822.000 966.000 370.000 516.000 110.360 541.381 ns 71.55 331.3
Server Jitter 104.131.155.175 0.576 0.576 0.734 1.489 54.779 54.790 54.790 54.044 54.214 18.651 8.996 ms 0.3469 2.62
Server Jitter 162.159.200.1 0.326 0.326 0.513 1.153 6.848 13.356 13.356 6.335 13.030 2.469 2.102 ms 2.16 8.759
Server Jitter 169.229.128.134 0.191 0.191 0.366 1.068 11.823 30.441 30.441 11.457 30.251 4.293 2.271 ms 3.214 21.12
Server Jitter 173.11.101.155 0.893 0.893 0.946 1.734 12.048 12.533 12.533 11.102 11.640 2.494 2.483 ms 3.287 13.03
Server Jitter 178.62.68.79 0.524 0.524 0.524 1.408 145.303 145.303 145.303 144.779 144.779 50.829 24.136 ms 0.1536 2.317
Server Jitter 192.168.1.11 0.000 0.068 0.124 0.549 6.028 12.199 13.496 5.904 12.132 2.129 1.145 ms 2.417 12.74
Server Jitter 204.17.205.23 0.000 0.000 0.313 1.487 11.124 11.124 11.124 10.811 11.124 3.707 3.038 ms 0.9466 2.603
Server Jitter 216.218.192.202 0.412 0.412 0.540 1.416 9.915 49.639 49.639 9.375 49.227 6.791 2.928 ms 3.986 28.25
Server Jitter 216.218.254.202 0.231 0.231 0.406 1.130 12.265 15.168 15.168 11.859 14.937 3.888 2.679 ms 1.326 4.586
Server Jitter 45.33.37.82 0.250 0.250 0.466 1.260 14.092 135.466 135.466 13.626 135.215 26.064 7.100 ms 2.092 12.82
Server Jitter 91.200.61.123 0.501 0.501 0.758 1.396 47.946 47.946 47.946 47.188 47.445 10.441 5.616 ms 1.822 8.767
Server Jitter SHM(0) 0.069 0.171 0.316 0.928 2.223 3.150 5.104 1.907 2.979 0.614 1.054 ms 4.045 14.56
Server Jitter SHM(1) 0.138 0.199 0.266 0.503 0.938 1.188 1.748 0.672 0.989 0.211 0.543 µs 9.83 33.59
Server Offset 104.131.155.175 2.658 2.658 2.889 3.389 4.028 4.259 4.259 1.138 1.601 0.416 3.478 ms 422 3275
Server Offset 162.159.200.1 4.463 4.463 4.691 5.070 5.587 5.762 5.762 0.896 1.299 0.288 5.112 ms 4726 7.988e+04
Server Offset 169.229.128.134 2.039 2.039 2.132 2.396 2.697 2.810 2.810 0.565 0.771 0.189 2.397 ms 1621 1.932e+04
Server Offset 173.11.101.155 -1.628 -1.628 -1.232 -0.085 0.922 1.483 1.483 2.154 3.111 0.614 -0.142 ms -5.564 15.05
Server Offset 178.62.68.79 -2.970 -2.970 -2.970 1.242 10.581 10.581 10.581 13.551 13.551 2.573 1.501 ms 0.6231 6.735
Server Offset 192.168.1.11 -515.749 -473.818 -347.486 -78.736 70.357 153.292 276.283 417.843 627.110 119.117 -94.947 µs -12.06 40.66
Server Offset 204.17.205.23 0.864 0.864 0.995 1.446 2.475 2.475 2.475 1.480 1.611 0.485 1.538 ms 17.27 57.31
Server Offset 216.218.192.202 1.859 1.859 2.097 2.436 2.900 3.361 3.361 0.803 1.502 0.247 2.431 ms 718.7 6619
Server Offset 216.218.254.202 1.777 1.777 1.867 2.348 2.739 3.088 3.088 0.872 1.311 0.266 2.340 ms 500.4 4097
Server Offset 45.33.37.82 1.733 1.733 2.334 2.906 3.633 4.141 4.141 1.299 2.408 0.389 2.917 ms 294.8 2051
Server Offset 91.200.61.123 0.392 0.392 0.433 0.927 1.564 1.564 1.564 1.131 1.172 0.305 0.901 ms 13.63 42.66
Server Offset SHM(0) -55.569 -53.983 -52.908 -48.723 -44.495 -42.121 -40.830 8.414 11.862 2.517 -48.861 ms -8566 1.761e+05
Server Offset SHM(1) -1.413 -1.017 -0.706 0.002 0.652 0.956 1.299 1.358 1.973 0.412 -0.005 µs -4.14 10.5
TDOP 0.490 0.500 0.550 0.810 1.460 1.490 1.870 0.910 0.990 0.259 0.865 20.85 77.28
Temp ZONE0 54.768 54.768 55.306 55.844 56.382 56.382 56.920 1.076 1.614 0.348 55.847 °C
nSats 6.000 7.000 7.000 9.000 11.000 12.000 12.000 4.000 5.000 1.126 9.273 nSat 400.2 3052
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!