NTPsec

A-ntpsec-3-hour-stats

Report generated: Wed Oct 23 21:03:55 2019 UTC
Start Time: Wed Oct 23 18:03:52 2019 UTC
End Time: Wed Oct 23 21:03:52 2019 UTC
Report published: Wed Oct 23 14:04:12 2019 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 -734.000 -590.000 -439.000 -118.000 226.000 334.000 526.000 665.000 924.000 203.376 -111.988 ns -8.418 23.33
Local Clock Frequency Offset -538.971 -538.895 -538.025 -524.078 -519.394 -518.845 -518.646 18.631 20.050 5.754 -525.759 ppb -7.883e+05 7.284e+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 83.000 88.000 111.000 159.000 235.000 260.000 275.000 124.000 172.000 38.026 164.520 ns 47.26 197.8

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 23.000 25.000 30.000 49.000 106.000 119.000 125.000 76.000 94.000 20.835 53.419 10e-12 9.949 34.51

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 -734.000 -590.000 -439.000 -118.000 226.000 334.000 526.000 665.000 924.000 203.376 -111.988 ns -8.418 23.33

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 -538.971 -538.895 -538.025 -524.078 -519.394 -518.845 -518.646 18.631 20.050 5.754 -525.759 ppb -7.883e+05 7.284e+07
Temp ZONE0 59.072 59.072 59.610 60.148 60.686 60.686 60.686 1.076 1.614 0.277 60.112 °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 8.000 8.000 8.000 10.000 12.000 12.000 12.000 4.000 4.000 1.242 9.781 nSat 345.9 2524
TDOP 0.570 0.570 0.580 0.710 1.470 1.490 1.500 0.890 0.920 0.307 0.872 12.76 41.61

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. TDOP ranges from 1 to greater than 20. 1 denotes the highest possible confidence level. 2 to 5 is good. Greater than 20 means there will be significant inaccuracy and error.



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 2.385 2.385 2.417 3.385 6.059 6.789 6.789 3.642 4.404 1.073 3.483 ms 19.85 77.47

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 3.011 3.011 3.011 4.892 6.318 6.318 6.318 3.307 3.307 1.107 4.471 ms 37.22 142.9

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 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 -164.745 -156.186 -90.556 30.688 165.637 465.640 777.954 256.193 621.826 99.416 36.276 µs 1.017 18.29

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 192.168.1.12

peer offset 192.168.1.12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 192.168.1.12 -529.885 -526.062 -310.069 -73.830 132.195 443.236 729.435 442.264 969.298 149.278 -76.055 µs -7.188 23.84

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 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 2.518 2.518 2.538 3.348 3.942 3.994 3.994 1.404 1.476 0.364 3.309 ms 555.6 4696

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 0.559 0.559 0.838 1.687 2.311 2.522 2.522 1.473 1.962 0.437 1.640 ms 28.79 101.9

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 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 2.142 2.142 2.160 2.736 3.381 3.462 3.462 1.220 1.320 0.336 2.780 ms 407.9 3136

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 2.059 2.059 2.152 2.635 3.163 3.253 3.253 1.011 1.195 0.330 2.607 ms 348.7 2554

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) -69.231 -61.973 -59.734 -54.132 -47.105 -45.582 -44.418 12.629 16.391 3.777 -53.727 ms -3574 5.51e+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) -735.000 -591.000 -440.000 -119.000 227.000 335.000 527.000 667.000 926.000 204.054 -112.365 ns -8.413 23.29

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 0.000 1.740 3.758 4.087 4.087 3.758 4.087 1.163 1.883 ms 2.327 5.08

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 2.288 2.288 2.288 5.412 76.117 76.117 76.117 73.829 73.829 33.522 28.501 ms 0.2493 1.215

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 0.130 0.136 0.208 0.785 75.490 75.625 75.802 75.282 75.488 28.112 13.968 ms 0.0794 2.09

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 192.168.1.12

peer jitter 192.168.1.12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 192.168.1.12 0.157 0.164 0.210 0.795 75.208 75.397 79.504 74.998 75.234 21.225 8.607 ms 0.7965 4.545

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 0.538 0.538 0.707 2.572 9.248 75.800 75.800 8.541 75.262 12.196 5.590 ms 3.497 20.92

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 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 0.506 0.506 0.574 1.753 75.558 75.581 75.581 74.984 75.075 21.931 10.098 ms 0.7643 4.053

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 0.531 0.531 0.600 2.370 34.555 34.607 34.607 33.955 34.076 7.893 4.634 ms 1.979 8.209

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 0.683 0.683 0.703 2.704 101.711 101.724 101.724 101.008 101.041 35.296 21.224 ms 0.2458 2.05

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 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) 0.120 0.360 0.502 1.199 3.380 6.357 12.606 2.878 5.998 1.115 1.527 ms 3.808 18.85

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) 34.000 58.000 83.000 158.000 317.000 415.000 565.000 234.000 357.000 75.640 173.816 ns 7.317 24.75

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 -538.971 -538.895 -538.025 -524.078 -519.394 -518.845 -518.646 18.631 20.050 5.754 -525.759 ppb -7.883e+05 7.284e+07
Local Clock Time Offset -734.000 -590.000 -439.000 -118.000 226.000 334.000 526.000 665.000 924.000 203.376 -111.988 ns -8.418 23.33
Local RMS Frequency Jitter 23.000 25.000 30.000 49.000 106.000 119.000 125.000 76.000 94.000 20.835 53.419 10e-12 9.949 34.51
Local RMS Time Jitter 83.000 88.000 111.000 159.000 235.000 260.000 275.000 124.000 172.000 38.026 164.520 ns 47.26 197.8
Server Jitter 104.131.155.175 0.000 0.000 0.000 1.740 3.758 4.087 4.087 3.758 4.087 1.163 1.883 ms 2.327 5.08
Server Jitter 178.62.68.79 2.288 2.288 2.288 5.412 76.117 76.117 76.117 73.829 73.829 33.522 28.501 ms 0.2493 1.215
Server Jitter 192.168.1.11 0.130 0.136 0.208 0.785 75.490 75.625 75.802 75.282 75.488 28.112 13.968 ms 0.0794 2.09
Server Jitter 192.168.1.12 0.157 0.164 0.210 0.795 75.208 75.397 79.504 74.998 75.234 21.225 8.607 ms 0.7965 4.545
Server Jitter 203.123.48.219 0.538 0.538 0.707 2.572 9.248 75.800 75.800 8.541 75.262 12.196 5.590 ms 3.497 20.92
Server Jitter 204.17.205.24 0.506 0.506 0.574 1.753 75.558 75.581 75.581 74.984 75.075 21.931 10.098 ms 0.7643 4.053
Server Jitter 216.218.192.202 0.531 0.531 0.600 2.370 34.555 34.607 34.607 33.955 34.076 7.893 4.634 ms 1.979 8.209
Server Jitter 216.218.254.202 0.683 0.683 0.703 2.704 101.711 101.724 101.724 101.008 101.041 35.296 21.224 ms 0.2458 2.05
Server Jitter SHM(0) 0.120 0.360 0.502 1.199 3.380 6.357 12.606 2.878 5.998 1.115 1.527 ms 3.808 18.85
Server Jitter SHM(1) 34.000 58.000 83.000 158.000 317.000 415.000 565.000 234.000 357.000 75.640 173.816 ns 7.317 24.75
Server Offset 104.131.155.175 2.385 2.385 2.417 3.385 6.059 6.789 6.789 3.642 4.404 1.073 3.483 ms 19.85 77.47
Server Offset 178.62.68.79 3.011 3.011 3.011 4.892 6.318 6.318 6.318 3.307 3.307 1.107 4.471 ms 37.22 142.9
Server Offset 192.168.1.11 -164.745 -156.186 -90.556 30.688 165.637 465.640 777.954 256.193 621.826 99.416 36.276 µs 1.017 18.29
Server Offset 192.168.1.12 -529.885 -526.062 -310.069 -73.830 132.195 443.236 729.435 442.264 969.298 149.278 -76.055 µs -7.188 23.84
Server Offset 203.123.48.219 2.518 2.518 2.538 3.348 3.942 3.994 3.994 1.404 1.476 0.364 3.309 ms 555.6 4696
Server Offset 204.17.205.24 0.559 0.559 0.838 1.687 2.311 2.522 2.522 1.473 1.962 0.437 1.640 ms 28.79 101.9
Server Offset 216.218.192.202 2.142 2.142 2.160 2.736 3.381 3.462 3.462 1.220 1.320 0.336 2.780 ms 407.9 3136
Server Offset 216.218.254.202 2.059 2.059 2.152 2.635 3.163 3.253 3.253 1.011 1.195 0.330 2.607 ms 348.7 2554
Server Offset SHM(0) -69.231 -61.973 -59.734 -54.132 -47.105 -45.582 -44.418 12.629 16.391 3.777 -53.727 ms -3574 5.51e+04
Server Offset SHM(1) -735.000 -591.000 -440.000 -119.000 227.000 335.000 527.000 667.000 926.000 204.054 -112.365 ns -8.413 23.29
TDOP 0.570 0.570 0.580 0.710 1.470 1.490 1.500 0.890 0.920 0.307 0.872 12.76 41.61
Temp ZONE0 59.072 59.072 59.610 60.148 60.686 60.686 60.686 1.076 1.614 0.277 60.112 °C
nSats 8.000 8.000 8.000 10.000 12.000 12.000 12.000 4.000 4.000 1.242 9.781 nSat 345.9 2524
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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