NTPsec

C-ntpsec-12-hour-stats

Report generated: Tue Apr 20 13:01:45 2021 UTC
Start Time: Tue Apr 20 01:01:45 2021 UTC
End Time: Tue Apr 20 13:01:45 2021 UTC
Report published: Tue Apr 20 06:01:51 2021 PDT
Report Period: 0.5 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 -1.005 -0.775 -0.254 0.348 0.665 1.188 1.123 1.670 0.351 -0.242 µs -9.609 26.85
Local Clock Frequency Offset -5.203 -5.200 -5.185 -5.033 -4.993 -4.992 -4.991 0.192 0.208 0.066 -5.058 ppm -4.77e+05 3.728e+07

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 79.000 97.000 119.000 175.000 263.000 337.000 525.000 144.000 240.000 48.019 181.805 ns 31.27 128.1

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 24.000 33.000 44.000 97.000 214.000 342.000 423.000 170.000 309.000 57.502 108.518 10e-12 5.177 19.71

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 -1.005 -0.775 -0.254 0.348 0.665 1.188 1.123 1.670 0.351 -0.242 µs -9.609 26.85

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 -5.203 -5.200 -5.185 -5.033 -4.993 -4.992 -4.991 0.192 0.208 0.066 -5.058 ppm -4.77e+05 3.728e+07
Temp ZONE0 56.920 56.920 57.458 59.072 60.148 60.148 60.148 2.690 3.228 0.878 58.865 °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 12.000 12.000 3.000 5.000 1.195 9.700 nSat 381.3 2861
TDOP 0.550 0.570 0.580 0.800 1.210 1.520 2.020 0.630 0.950 0.208 0.857 40.89 176.6

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 1.832 1.832 1.885 2.211 2.642 4.878 4.878 0.757 3.047 0.515 2.291 ms 55.17 282

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 2.180 2.216 2.306 2.543 2.824 2.956 3.009 0.517 0.739 0.154 2.548 ms 3790 5.959e+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 2.202 2.215 2.341 2.559 2.830 2.972 3.055 0.489 0.758 0.156 2.584 ms 3837 6.057e+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 -1.102 -0.597 0.256 0.772 1.308 1.369 1.368 2.409 0.437 0.225 ms -2.385 8.101

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 1.557 2.765 5.209 5.568 5.568 3.652 4.899 1.023 2.992 ms 13.59 44.67

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 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 -93.463 66.021 89.499 159.333 377.155 439.710 475.423 287.656 373.689 76.348 172.682 µs 7.539 27.65

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 3.007 6.328 6.471 8.042 8.358 8.489 8.711 1.888 2.161 0.798 7.646 ms 656.7 5822

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 1.857 1.873 1.945 3.651 4.048 4.133 4.174 2.103 2.260 0.780 3.266 ms 41.17 155.9

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

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

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

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



Server Offset 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 0.282 0.411 0.655 0.913 1.010 1.042 0.502 0.728 0.158 0.654 ms 40.15 158.4

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 1.909 1.909 1.950 2.155 2.349 2.376 2.376 0.399 0.467 0.115 2.151 ms 5548 9.883e+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 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 3.207 3.306 3.537 3.815 3.974 4.028 0.509 0.767 0.160 3.549 ms 9475 2.014e+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) -67.140 -64.953 -62.412 -55.840 -48.241 -46.706 -44.016 14.171 18.248 4.209 -55.904 ms -2955 4.281e+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 -1.006 -0.776 -0.255 0.349 0.666 1.189 1.125 1.672 0.351 -0.242 µs -9.609 26.84

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 0.000 0.000 0.223 1.302 8.812 12.561 12.561 8.589 12.561 3.151 2.611 ms 1.163 3.558

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 0.147 0.158 0.240 1.680 8.829 9.888 12.752 8.590 9.730 2.810 2.843 ms 1.443 4.076

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 0.136 0.165 0.241 1.030 8.840 9.712 9.745 8.599 9.547 2.865 2.327 ms 0.9766 2.871

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 0.384 0.404 0.711 1.638 9.735 23.339 39.691 9.024 22.935 5.093 3.713 ms 2.891 18.05

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 0.483 0.483 0.522 1.523 11.176 77.012 77.012 10.654 76.529 12.307 4.266 ms 3.335 21.17

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 0.042 0.067 0.193 8.679 8.803 10.552 8.612 8.762 2.362 1.140 ms 0.9108 4.639

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 0.153 0.179 0.208 1.462 9.581 12.446 12.477 9.374 12.267 3.188 2.942 ms 1.115 3.231

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 0.231 0.291 0.473 1.599 9.457 15.257 15.265 8.984 14.966 3.187 3.223 ms 1.544 4.788

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 0.109 0.146 0.257 1.794 12.089 13.094 13.137 11.832 12.948 3.464 3.403 ms 1.259 3.704

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 0.169 0.169 0.257 1.408 8.951 72.220 72.220 8.693 72.051 8.687 3.616 ms 4.999 40.74

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 204.17.205.24

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 0.156 0.161 0.256 1.132 8.828 10.042 13.420 8.572 9.882 2.669 2.244 ms 1.419 4.95

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) 0.130 0.230 0.334 0.951 3.111 5.692 8.507 2.777 5.462 0.990 1.221 ms 3.373 14.99

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) 47.000 69.000 97.000 212.000 509.000 714.000 1,083.000 412.000 645.000 133.667 246.472 ns 4.737 16.94

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 -5.203 -5.200 -5.185 -5.033 -4.993 -4.992 -4.991 0.192 0.208 0.066 -5.058 ppm -4.77e+05 3.728e+07
Local Clock Time Offset -1.403 -1.005 -0.775 -0.254 0.348 0.665 1.188 1.123 1.670 0.351 -0.242 µs -9.609 26.85
Local RMS Frequency Jitter 24.000 33.000 44.000 97.000 214.000 342.000 423.000 170.000 309.000 57.502 108.518 10e-12 5.177 19.71
Local RMS Time Jitter 79.000 97.000 119.000 175.000 263.000 337.000 525.000 144.000 240.000 48.019 181.805 ns 31.27 128.1
Server Jitter 104.131.155.175 0.000 0.000 0.223 1.302 8.812 12.561 12.561 8.589 12.561 3.151 2.611 ms 1.163 3.558
Server Jitter 162.159.200.1 0.147 0.158 0.240 1.680 8.829 9.888 12.752 8.590 9.730 2.810 2.843 ms 1.443 4.076
Server Jitter 162.159.200.123 0.136 0.165 0.241 1.030 8.840 9.712 9.745 8.599 9.547 2.865 2.327 ms 0.9766 2.871
Server Jitter 173.11.101.155 0.384 0.404 0.711 1.638 9.735 23.339 39.691 9.024 22.935 5.093 3.713 ms 2.891 18.05
Server Jitter 178.62.68.79 0.483 0.483 0.522 1.523 11.176 77.012 77.012 10.654 76.529 12.307 4.266 ms 3.335 21.17
Server Jitter 192.168.1.10 0.023 0.042 0.067 0.193 8.679 8.803 10.552 8.612 8.762 2.362 1.140 ms 0.9108 4.639
Server Jitter 194.58.202.211 0.153 0.179 0.208 1.462 9.581 12.446 12.477 9.374 12.267 3.188 2.942 ms 1.115 3.231
Server Jitter 194.58.202.219 0.231 0.291 0.473 1.599 9.457 15.257 15.265 8.984 14.966 3.187 3.223 ms 1.544 4.788
Server Jitter 203.123.48.219 0.109 0.146 0.257 1.794 12.089 13.094 13.137 11.832 12.948 3.464 3.403 ms 1.259 3.704
Server Jitter 204.123.2.5 0.169 0.169 0.257 1.408 8.951 72.220 72.220 8.693 72.051 8.687 3.616 ms 4.999 40.74
Server Jitter 204.17.205.24 0.156 0.161 0.256 1.132 8.828 10.042 13.420 8.572 9.882 2.669 2.244 ms 1.419 4.95
Server Jitter SHM(0) 0.130 0.230 0.334 0.951 3.111 5.692 8.507 2.777 5.462 0.990 1.221 ms 3.373 14.99
Server Jitter SHM(1) 47.000 69.000 97.000 212.000 509.000 714.000 1,083.000 412.000 645.000 133.667 246.472 ns 4.737 16.94
Server Offset 104.131.155.175 1.832 1.832 1.885 2.211 2.642 4.878 4.878 0.757 3.047 0.515 2.291 ms 55.17 282
Server Offset 162.159.200.1 2.180 2.216 2.306 2.543 2.824 2.956 3.009 0.517 0.739 0.154 2.548 ms 3790 5.959e+04
Server Offset 162.159.200.123 2.202 2.215 2.341 2.559 2.830 2.972 3.055 0.489 0.758 0.156 2.584 ms 3837 6.057e+04
Server Offset 173.11.101.155 -1.549 -1.102 -0.597 0.256 0.772 1.308 1.369 1.368 2.409 0.437 0.225 ms -2.385 8.101
Server Offset 178.62.68.79 0.670 0.670 1.557 2.765 5.209 5.568 5.568 3.652 4.899 1.023 2.992 ms 13.59 44.67
Server Offset 192.168.1.10 -93.463 66.021 89.499 159.333 377.155 439.710 475.423 287.656 373.689 76.348 172.682 µs 7.539 27.65
Server Offset 194.58.202.211 3.007 6.328 6.471 8.042 8.358 8.489 8.711 1.888 2.161 0.798 7.646 ms 656.7 5822
Server Offset 194.58.202.219 1.857 1.873 1.945 3.651 4.048 4.133 4.174 2.103 2.260 0.780 3.266 ms 41.17 155.9
Server Offset 203.123.48.219 0.154 0.282 0.411 0.655 0.913 1.010 1.042 0.502 0.728 0.158 0.654 ms 40.15 158.4
Server Offset 204.123.2.5 1.909 1.909 1.950 2.155 2.349 2.376 2.376 0.399 0.467 0.115 2.151 ms 5548 9.883e+04
Server Offset 204.17.205.24 3.026 3.207 3.306 3.537 3.815 3.974 4.028 0.509 0.767 0.160 3.549 ms 9475 2.014e+05
Server Offset SHM(0) -67.140 -64.953 -62.412 -55.840 -48.241 -46.706 -44.016 14.171 18.248 4.209 -55.904 ms -2955 4.281e+04
Server Offset SHM(1) -1.404 -1.006 -0.776 -0.255 0.349 0.666 1.189 1.125 1.672 0.351 -0.242 µs -9.609 26.84
TDOP 0.550 0.570 0.580 0.800 1.210 1.520 2.020 0.630 0.950 0.208 0.857 40.89 176.6
Temp ZONE0 56.920 56.920 57.458 59.072 60.148 60.148 60.148 2.690 3.228 0.878 58.865 °C
nSats 7.000 7.000 8.000 10.000 11.000 12.000 12.000 3.000 5.000 1.195 9.700 nSat 381.3 2861
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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