NTPsec

C-ntpsec-3-hour-stats

Report generated: Tue Apr 20 14:01:21 2021 UTC
Start Time: Tue Apr 20 11:01:20 2021 UTC
End Time: Tue Apr 20 14:01:20 2021 UTC
Report published: Tue Apr 20 07:01:26 2021 PDT
Report Period: 0.1 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 -1.403 -1.252 -0.903 -0.309 0.269 0.570 0.746 1.172 1.822 0.359 -0.320 µs -12.45 37.68
Local Clock Frequency Offset -5.209 -5.209 -5.209 -5.184 -5.134 -5.132 -5.132 0.074 0.077 0.026 -5.179 ppm -8.231e+06 1.662e+09

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 99.000 119.000 128.000 172.000 271.000 339.000 395.000 143.000 220.000 45.317 181.773 ns 37.74 159.1

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 21.000 27.000 43.000 117.000 325.000 387.000 423.000 282.000 360.000 79.336 138.241 10e-12 3.974 12.14

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 -1.403 -1.252 -0.903 -0.309 0.269 0.570 0.746 1.172 1.822 0.359 -0.320 µs -12.45 37.68

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 -5.209 -5.209 -5.209 -5.184 -5.134 -5.132 -5.132 0.074 0.077 0.026 -5.179 ppm -8.231e+06 1.662e+09
Temp ZONE0 56.382 56.382 56.920 57.458 57.996 58.534 58.534 1.076 2.152 0.496 57.386 °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 7.000 7.000 8.000 10.000 11.000 11.000 11.000 3.000 4.000 0.914 9.622 nSat 893.4 8773
TDOP 0.620 0.620 0.640 0.780 1.210 2.000 2.020 0.570 1.380 0.217 0.835 34.42 162.1

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 1.853 1.853 1.853 2.067 2.211 2.211 2.211 0.358 0.358 0.124 2.022 ms 3663 5.693e+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 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 2.216 2.216 2.266 2.545 2.812 2.857 2.857 0.546 0.642 0.145 2.547 ms 4614 7.737e+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 162.159.200.123

peer offset 162.159.200.123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 162.159.200.123 2.296 2.296 2.330 2.586 2.871 2.929 2.929 0.542 0.633 0.157 2.584 ms 3734 5.841e+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 -1.549 -1.549 -0.748 0.198 0.699 0.800 0.800 1.447 2.348 0.457 0.135 ms -4.074 14.32

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 0.670 0.670 0.670 2.821 3.966 3.966 3.966 3.297 3.297 0.814 2.761 ms 19.89 62.37

The offset of a server in seconds. This is useful to see how the measured offset is behaving.

The chart also plots offset±rtt, where rtt is the round trip time to the server. NTP can not really know the offset of a remote chimer, NTP computes it by subtracting rtt/2 from the offset. Plotting the offset±rtt reverses this calculation to more easily see the effects of rtt changes.

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local LAN server 80µs; 90% ranges for WAN server may be 4ms and much larger.

Clock Offset is field 5 in the peerstats log file. The Round Trip Time (rtt) is field 6 in the peerstats log file.



Server Offset 192.168.1.10

peer offset 192.168.1.10 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.10 50.077 76.112 93.044 166.330 404.804 468.331 475.423 311.760 392.219 93.895 196.506 µs 5.834 17.77

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 194.58.202.211

peer offset 194.58.202.211 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 194.58.202.211 7.756 7.756 7.900 8.077 8.214 8.317 8.317 0.314 0.561 0.106 8.069 ms 4.191e+05 3.137e+07

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 194.58.202.219

peer offset 194.58.202.219 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 194.58.202.219 3.488 3.488 3.522 3.737 4.133 4.174 4.174 0.611 0.686 0.178 3.758 ms 8140 1.646e+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 203.123.48.219

peer offset 203.123.48.219 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 203.123.48.219 0.154 0.154 0.421 0.606 0.765 1.028 1.028 0.344 0.874 0.147 0.592 ms 36.99 145.6

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 204.123.2.5

peer offset 204.123.2.5 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.123.2.5 1.965 1.965 1.965 2.094 2.300 2.300 2.300 0.335 0.335 0.105 2.136 ms 7270 1.416e+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 204.17.205.24

peer offset 204.17.205.24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 204.17.205.24 3.026 3.026 3.207 3.497 3.735 3.766 3.766 0.527 0.740 0.148 3.490 ms 1.16e+04 2.635e+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(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) -64.843 -63.316 -62.064 -55.011 -49.739 -47.338 -45.025 12.325 15.978 3.968 -55.570 ms -3423 5.204e+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 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) -1.404 -1.253 -0.904 -0.310 0.270 0.571 0.747 1.174 1.824 0.360 -0.320 µs -12.46 37.67

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 0.170 0.170 0.170 0.968 1.981 1.981 1.981 1.811 1.811 0.611 0.857 ms 1.704 3.435

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 0.201 0.201 0.220 1.864 7.087 8.628 8.628 6.866 8.428 2.007 2.453 ms 2.222 6.479

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 162.159.200.123

peer jitter 162.159.200.123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 162.159.200.123 0.096 0.096 0.213 0.879 8.840 8.925 8.925 8.626 8.829 2.783 1.906 ms 0.8788 2.916

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 0.404 0.404 0.819 2.438 21.463 23.339 23.339 20.644 22.935 5.871 5.712 ms 1.495 5.081

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 1.048 1.048 1.048 2.082 9.014 9.014 9.014 7.967 7.967 3.444 4.437 ms 1.226 2.06

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 192.168.1.10

peer jitter 192.168.1.10 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.10 0.023 0.031 0.053 0.171 8.714 8.882 8.892 8.661 8.851 2.521 1.039 ms 0.7169 4.196

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 194.58.202.211

peer jitter 194.58.202.211 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 194.58.202.211 0.137 0.137 0.182 0.816 9.988 10.506 10.506 9.806 10.369 3.357 2.627 ms 0.588 2.134

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 194.58.202.219

peer jitter 194.58.202.219 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 194.58.202.219 0.178 0.178 0.181 1.331 11.772 11.902 11.902 11.592 11.723 3.373 2.660 ms 0.9162 2.998

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 203.123.48.219

peer jitter 203.123.48.219 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 203.123.48.219 0.244 0.244 0.249 1.017 8.810 8.875 8.875 8.561 8.632 3.433 3.207 ms 0.5806 1.608

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 204.123.2.5

peer jitter 204.123.2.5 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.123.2.5 0.503 0.503 0.503 1.399 9.154 9.154 9.154 8.651 8.651 3.143 3.036 ms 0.9823 2.315

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 204.17.205.24

peer jitter 204.17.205.24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 204.17.205.24 0.226 0.226 0.243 0.600 8.781 8.818 8.818 8.538 8.593 2.542 1.853 ms 1.086 3.801

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) 0.113 0.227 0.322 1.048 3.207 5.541 7.131 2.885 5.315 1.001 1.299 ms 3.258 13.7

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 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) 61.000 83.000 101.000 227.000 549.000 722.000 987.000 448.000 639.000 142.400 260.700 ns 4.463 14.8

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -5.209 -5.209 -5.209 -5.184 -5.134 -5.132 -5.132 0.074 0.077 0.026 -5.179 ppm -8.231e+06 1.662e+09
Local Clock Time Offset -1.403 -1.252 -0.903 -0.309 0.269 0.570 0.746 1.172 1.822 0.359 -0.320 µs -12.45 37.68
Local RMS Frequency Jitter 21.000 27.000 43.000 117.000 325.000 387.000 423.000 282.000 360.000 79.336 138.241 10e-12 3.974 12.14
Local RMS Time Jitter 99.000 119.000 128.000 172.000 271.000 339.000 395.000 143.000 220.000 45.317 181.773 ns 37.74 159.1
Server Jitter 104.131.155.175 0.170 0.170 0.170 0.968 1.981 1.981 1.981 1.811 1.811 0.611 0.857 ms 1.704 3.435
Server Jitter 162.159.200.1 0.201 0.201 0.220 1.864 7.087 8.628 8.628 6.866 8.428 2.007 2.453 ms 2.222 6.479
Server Jitter 162.159.200.123 0.096 0.096 0.213 0.879 8.840 8.925 8.925 8.626 8.829 2.783 1.906 ms 0.8788 2.916
Server Jitter 173.11.101.155 0.404 0.404 0.819 2.438 21.463 23.339 23.339 20.644 22.935 5.871 5.712 ms 1.495 5.081
Server Jitter 178.62.68.79 1.048 1.048 1.048 2.082 9.014 9.014 9.014 7.967 7.967 3.444 4.437 ms 1.226 2.06
Server Jitter 192.168.1.10 0.023 0.031 0.053 0.171 8.714 8.882 8.892 8.661 8.851 2.521 1.039 ms 0.7169 4.196
Server Jitter 194.58.202.211 0.137 0.137 0.182 0.816 9.988 10.506 10.506 9.806 10.369 3.357 2.627 ms 0.588 2.134
Server Jitter 194.58.202.219 0.178 0.178 0.181 1.331 11.772 11.902 11.902 11.592 11.723 3.373 2.660 ms 0.9162 2.998
Server Jitter 203.123.48.219 0.244 0.244 0.249 1.017 8.810 8.875 8.875 8.561 8.632 3.433 3.207 ms 0.5806 1.608
Server Jitter 204.123.2.5 0.503 0.503 0.503 1.399 9.154 9.154 9.154 8.651 8.651 3.143 3.036 ms 0.9823 2.315
Server Jitter 204.17.205.24 0.226 0.226 0.243 0.600 8.781 8.818 8.818 8.538 8.593 2.542 1.853 ms 1.086 3.801
Server Jitter SHM(0) 0.113 0.227 0.322 1.048 3.207 5.541 7.131 2.885 5.315 1.001 1.299 ms 3.258 13.7
Server Jitter SHM(1) 61.000 83.000 101.000 227.000 549.000 722.000 987.000 448.000 639.000 142.400 260.700 ns 4.463 14.8
Server Offset 104.131.155.175 1.853 1.853 1.853 2.067 2.211 2.211 2.211 0.358 0.358 0.124 2.022 ms 3663 5.693e+04
Server Offset 162.159.200.1 2.216 2.216 2.266 2.545 2.812 2.857 2.857 0.546 0.642 0.145 2.547 ms 4614 7.737e+04
Server Offset 162.159.200.123 2.296 2.296 2.330 2.586 2.871 2.929 2.929 0.542 0.633 0.157 2.584 ms 3734 5.841e+04
Server Offset 173.11.101.155 -1.549 -1.549 -0.748 0.198 0.699 0.800 0.800 1.447 2.348 0.457 0.135 ms -4.074 14.32
Server Offset 178.62.68.79 0.670 0.670 0.670 2.821 3.966 3.966 3.966 3.297 3.297 0.814 2.761 ms 19.89 62.37
Server Offset 192.168.1.10 50.077 76.112 93.044 166.330 404.804 468.331 475.423 311.760 392.219 93.895 196.506 µs 5.834 17.77
Server Offset 194.58.202.211 7.756 7.756 7.900 8.077 8.214 8.317 8.317 0.314 0.561 0.106 8.069 ms 4.191e+05 3.137e+07
Server Offset 194.58.202.219 3.488 3.488 3.522 3.737 4.133 4.174 4.174 0.611 0.686 0.178 3.758 ms 8140 1.646e+05
Server Offset 203.123.48.219 0.154 0.154 0.421 0.606 0.765 1.028 1.028 0.344 0.874 0.147 0.592 ms 36.99 145.6
Server Offset 204.123.2.5 1.965 1.965 1.965 2.094 2.300 2.300 2.300 0.335 0.335 0.105 2.136 ms 7270 1.416e+05
Server Offset 204.17.205.24 3.026 3.026 3.207 3.497 3.735 3.766 3.766 0.527 0.740 0.148 3.490 ms 1.16e+04 2.635e+05
Server Offset SHM(0) -64.843 -63.316 -62.064 -55.011 -49.739 -47.338 -45.025 12.325 15.978 3.968 -55.570 ms -3423 5.204e+04
Server Offset SHM(1) -1.404 -1.253 -0.904 -0.310 0.270 0.571 0.747 1.174 1.824 0.360 -0.320 µs -12.46 37.67
TDOP 0.620 0.620 0.640 0.780 1.210 2.000 2.020 0.570 1.380 0.217 0.835 34.42 162.1
Temp ZONE0 56.382 56.382 56.920 57.458 57.996 58.534 58.534 1.076 2.152 0.496 57.386 °C
nSats 7.000 7.000 8.000 10.000 11.000 11.000 11.000 3.000 4.000 0.914 9.622 nSat 893.4 8773
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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