NTPsec

A-ntpsec-6-hour-stats

Report generated: Sun Jul 3 07:02:28 2022 UTC
Start Time: Sun Jul 3 01:02:28 2022 UTC
End Time: Sun Jul 3 07:02:28 2022 UTC
Report published: Sun Jul 03 00:02:34 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 -1,412.000 -976.000 -692.000 0.000 602.000 883.000 1,176.000 1,294.000 1,859.000 398.936 -11.910 ns -4.28 10.9
Local Clock Frequency Offset -35.843 -35.645 -35.263 -31.647 -26.474 -26.062 -25.848 8.789 9.583 2.436 -31.406 ppb -2722 3.838e+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 260.000 291.000 357.000 524.000 728.000 847.000 966.000 371.000 556.000 111.849 531.308 ns 64.4 291.7

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 61.000 69.000 95.000 129.000 153.000 175.000 60.000 92.000 18.349 96.326 10e-12 90.13 449.3

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 -1,412.000 -976.000 -692.000 0.000 602.000 883.000 1,176.000 1,294.000 1,859.000 398.936 -11.910 ns -4.28 10.9

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 -35.843 -35.645 -35.263 -31.647 -26.474 -26.062 -25.848 8.789 9.583 2.436 -31.406 ppb -2722 3.838e+04
Temp ZONE0 54.768 54.768 54.768 55.844 56.382 56.382 56.920 1.614 1.614 0.403 55.757 °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 11.000 11.000 4.000 4.000 0.985 9.128 nSat 589.9 5074
TDOP 0.580 0.590 0.620 0.850 1.460 1.490 1.870 0.840 0.900 0.240 0.894 29.79 119

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 3.344 4.013 4.028 4.028 1.124 1.369 0.384 3.414 ms 516 4266

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 0.281 5.107 ms 5137 8.923e+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 2.397 2.692 2.810 2.810 0.560 0.771 0.179 2.398 ms 1937 2.446e+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 -0.038 0.922 1.483 1.483 2.154 3.111 0.600 -0.101 ms -5.232 14.57

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 -3.778 -3.778 -2.970 1.245 6.073 10.581 10.581 9.043 14.359 2.907 1.539 ms -0.4369 5.041

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 -726.601 -515.749 -410.738 -96.669 54.761 153.292 276.283 465.499 669.041 144.968 -128.727 µs -13.21 44.21

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 0.864 1.240 2.475 2.475 2.475 1.611 1.611 0.510 1.490 ms 13.49 42.77

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 1.995 2.444 2.900 3.361 3.361 0.906 1.502 0.250 2.429 ms 684.9 6210

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 2.676 3.088 3.088 0.809 1.311 0.260 2.329 ms 525.8 4373

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 2.839 3.633 4.141 4.141 1.299 2.408 0.392 2.869 ms 272.7 1857

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 0.433 0.433 0.433 1.001 1.564 1.564 1.564 1.131 1.131 0.305 0.931 ms 15.19 48.44

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) -55.380 -53.604 -51.897 -48.071 -44.401 -42.121 -40.830 7.495 11.483 2.256 -48.163 ms -1.123e+04 2.523e+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) -1,413.000 -977.000 -693.000 -1.000 603.000 884.000 1,177.000 1,296.000 1,861.000 399.728 -11.914 ns -4.279 10.89

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 0.462 0.462 0.576 1.254 54.779 54.790 54.790 54.203 54.328 18.738 8.780 ms 0.2948 2.602

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 0.389 1.131 6.848 13.356 13.356 6.458 13.030 2.538 2.051 ms 2.03 8.191

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 0.291 0.291 0.366 1.016 11.823 30.441 30.441 11.457 30.150 4.255 2.179 ms 3.2 21.41

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 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 0.982 1.849 12.048 12.533 12.533 11.066 11.640 2.480 2.533 ms 3.365 13.4

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 0.926 3.980 139.700 145.303 145.303 138.774 144.779 48.449 22.865 ms 0.3057 2.613

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 0.098 0.132 0.494 6.028 12.199 13.496 5.897 12.101 2.141 1.119 ms 2.314 12.33

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 0.000 1.331 11.124 11.124 11.124 11.124 11.124 4.160 3.543 ms 0.6413 1.818

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 0.313 0.313 0.412 1.292 9.915 49.639 49.639 9.503 49.327 6.876 2.852 ms 3.837 27.2

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 0.421 1.273 12.265 15.168 15.168 11.845 14.937 3.973 2.833 ms 1.302 4.341

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 0.314 0.314 0.421 1.260 14.092 135.466 135.466 13.671 135.152 26.066 7.094 ms 2.091 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 0.748 0.748 0.748 1.539 47.946 47.946 47.946 47.198 47.198 10.875 6.151 ms 1.729 7.92

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 0.177 0.330 0.920 2.157 3.240 5.492 1.827 3.062 0.614 1.047 ms 4.312 17.71

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 0.187 0.260 0.487 0.907 1.149 1.748 0.647 0.962 0.203 0.527 µs 10.01 34.58

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 -35.843 -35.645 -35.263 -31.647 -26.474 -26.062 -25.848 8.789 9.583 2.436 -31.406 ppb -2722 3.838e+04
Local Clock Time Offset -1,412.000 -976.000 -692.000 0.000 602.000 883.000 1,176.000 1,294.000 1,859.000 398.936 -11.910 ns -4.28 10.9
Local RMS Frequency Jitter 54.000 61.000 69.000 95.000 129.000 153.000 175.000 60.000 92.000 18.349 96.326 10e-12 90.13 449.3
Local RMS Time Jitter 260.000 291.000 357.000 524.000 728.000 847.000 966.000 371.000 556.000 111.849 531.308 ns 64.4 291.7
Server Jitter 104.131.155.175 0.462 0.462 0.576 1.254 54.779 54.790 54.790 54.203 54.328 18.738 8.780 ms 0.2948 2.602
Server Jitter 162.159.200.1 0.326 0.326 0.389 1.131 6.848 13.356 13.356 6.458 13.030 2.538 2.051 ms 2.03 8.191
Server Jitter 169.229.128.134 0.291 0.291 0.366 1.016 11.823 30.441 30.441 11.457 30.150 4.255 2.179 ms 3.2 21.41
Server Jitter 173.11.101.155 0.893 0.893 0.982 1.849 12.048 12.533 12.533 11.066 11.640 2.480 2.533 ms 3.365 13.4
Server Jitter 178.62.68.79 0.524 0.524 0.926 3.980 139.700 145.303 145.303 138.774 144.779 48.449 22.865 ms 0.3057 2.613
Server Jitter 192.168.1.11 0.000 0.098 0.132 0.494 6.028 12.199 13.496 5.897 12.101 2.141 1.119 ms 2.314 12.33
Server Jitter 204.17.205.23 0.000 0.000 0.000 1.331 11.124 11.124 11.124 11.124 11.124 4.160 3.543 ms 0.6413 1.818
Server Jitter 216.218.192.202 0.313 0.313 0.412 1.292 9.915 49.639 49.639 9.503 49.327 6.876 2.852 ms 3.837 27.2
Server Jitter 216.218.254.202 0.231 0.231 0.421 1.273 12.265 15.168 15.168 11.845 14.937 3.973 2.833 ms 1.302 4.341
Server Jitter 45.33.37.82 0.314 0.314 0.421 1.260 14.092 135.466 135.466 13.671 135.152 26.066 7.094 ms 2.091 12.82
Server Jitter 91.200.61.123 0.748 0.748 0.748 1.539 47.946 47.946 47.946 47.198 47.198 10.875 6.151 ms 1.729 7.92
Server Jitter SHM(0) 0.069 0.177 0.330 0.920 2.157 3.240 5.492 1.827 3.062 0.614 1.047 ms 4.312 17.71
Server Jitter SHM(1) 0.138 0.187 0.260 0.487 0.907 1.149 1.748 0.647 0.962 0.203 0.527 µs 10.01 34.58
Server Offset 104.131.155.175 2.658 2.658 2.889 3.344 4.013 4.028 4.028 1.124 1.369 0.384 3.414 ms 516 4266
Server Offset 162.159.200.1 4.463 4.463 4.691 5.070 5.587 5.762 5.762 0.896 1.299 0.281 5.107 ms 5137 8.923e+04
Server Offset 169.229.128.134 2.039 2.039 2.132 2.397 2.692 2.810 2.810 0.560 0.771 0.179 2.398 ms 1937 2.446e+04
Server Offset 173.11.101.155 -1.628 -1.628 -1.232 -0.038 0.922 1.483 1.483 2.154 3.111 0.600 -0.101 ms -5.232 14.57
Server Offset 178.62.68.79 -3.778 -3.778 -2.970 1.245 6.073 10.581 10.581 9.043 14.359 2.907 1.539 ms -0.4369 5.041
Server Offset 192.168.1.11 -726.601 -515.749 -410.738 -96.669 54.761 153.292 276.283 465.499 669.041 144.968 -128.727 µs -13.21 44.21
Server Offset 204.17.205.23 0.864 0.864 0.864 1.240 2.475 2.475 2.475 1.611 1.611 0.510 1.490 ms 13.49 42.77
Server Offset 216.218.192.202 1.859 1.859 1.995 2.444 2.900 3.361 3.361 0.906 1.502 0.250 2.429 ms 684.9 6210
Server Offset 216.218.254.202 1.777 1.777 1.867 2.348 2.676 3.088 3.088 0.809 1.311 0.260 2.329 ms 525.8 4373
Server Offset 45.33.37.82 1.733 1.733 2.334 2.839 3.633 4.141 4.141 1.299 2.408 0.392 2.869 ms 272.7 1857
Server Offset 91.200.61.123 0.433 0.433 0.433 1.001 1.564 1.564 1.564 1.131 1.131 0.305 0.931 ms 15.19 48.44
Server Offset SHM(0) -55.380 -53.604 -51.897 -48.071 -44.401 -42.121 -40.830 7.495 11.483 2.256 -48.163 ms -1.123e+04 2.523e+05
Server Offset SHM(1) -1,413.000 -977.000 -693.000 -1.000 603.000 884.000 1,177.000 1,296.000 1,861.000 399.728 -11.914 ns -4.279 10.89
TDOP 0.580 0.590 0.620 0.850 1.460 1.490 1.870 0.840 0.900 0.240 0.894 29.79 119
Temp ZONE0 54.768 54.768 54.768 55.844 56.382 56.382 56.920 1.614 1.614 0.403 55.757 °C
nSats 6.000 7.000 7.000 9.000 11.000 11.000 11.000 4.000 4.000 0.985 9.128 nSat 589.9 5074
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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