NTPsec

A-ntpsec-1-hour-stats

Report generated: Sun Jan 26 15:01:05 2020 UTC
Start Time: Sun Jan 26 14:00:37 2020 UTC
End Time: Sun Jan 26 15:01:05 2020 UTC
Report published: Sun Jan 26 07:01:10 2020 PST
Report Period: 0.0 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 -247.000 -77.000 3.000 243.000 504.000 572.000 616.000 501.000 649.000 146.119 245.097 ns 2.369 6.083
Local Clock Frequency Offset -664.291 -664.154 -663.696 -657.257 -649.658 -649.200 -649.185 14.038 14.954 4.740 -656.749 ppb -2.718e+06 3.794e+08

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 85.000 90.000 99.000 144.000 188.000 201.000 215.000 89.000 111.000 28.004 143.589 ns 82.74 395.1

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 42.000 43.000 47.000 69.000 137.000 162.000 171.000 90.000 119.000 24.915 74.559 10e-12 15.64 59.63

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 -247.000 -77.000 3.000 243.000 504.000 572.000 616.000 501.000 649.000 146.119 245.097 ns 2.369 6.083

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 -664.291 -664.154 -663.696 -657.257 -649.658 -649.200 -649.185 14.038 14.954 4.740 -656.749 ppb -2.718e+06 3.794e+08
Temp ZONE0 62.300 62.300 62.300 62.300 62.838 62.838 62.838 0.538 0.538 0.228 62.426 °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 9.000 9.000 9.000 10.000 12.000 12.000 12.000 3.000 3.000 0.744 10.344 nSat 2187 2.876e+04
TDOP 0.580 0.580 0.580 0.870 0.940 0.950 0.950 0.360 0.370 0.108 0.805 285.6 1949

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 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 -56.676 -56.676 -47.920 -11.293 74.271 76.941 76.941 122.191 133.617 34.517 -3.816 µs -3.842 7.939

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 -82.272 -82.272 -78.222 -41.888 49.910 77.113 77.113 128.132 159.385 36.855 -33.775 µs -11.39 29.13

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 2001:470:0:50::2 (clock.fmt.he.net)

peer offset 2001:470:0:50::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) 2.312 2.312 2.312 2.414 2.558 2.558 2.558 0.246 0.246 0.079 2.418 ms 2.591e+04 7.683e+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 2001:470:e815::24 (pi4.rellim.com)

peer offset 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:470:e815::24 (pi4.rellim.com) 3.927 3.927 3.927 4.266 4.600 4.600 4.600 0.673 0.673 0.203 4.311 ms 8288 1.685e+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 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 2.410 2.410 2.410 2.512 2.794 2.794 2.794 0.384 0.384 0.124 2.558 ms 7677 1.523e+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 2405:fc00:0:1::123

peer offset 2405:fc00:0:1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2405:fc00:0:1::123 11.122 11.122 11.122 11.402 11.712 11.712 11.712 0.590 0.590 0.157 11.405 ms 3.652e+05 2.612e+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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer offset 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 1.448 1.448 1.448 1.950 2.871 2.871 2.871 1.422 1.422 0.482 2.009 ms 41.98 171.6

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 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com)

peer offset 2a03:b0c0:1:d0::1f9:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 2.857 2.857 2.857 3.172 3.564 3.564 3.564 0.707 0.707 0.206 3.159 ms 2993 4.357e+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(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) -68.039 -62.610 -58.510 -53.732 -49.334 -48.677 -47.351 9.176 13.933 2.620 -53.862 ms -1.008e+04 2.187e+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) -248.000 -78.000 4.000 244.000 505.000 573.000 617.000 501.000 651.000 146.295 245.966 ns 2.379 6.112

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 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 0.034 0.034 0.048 0.144 8.648 8.712 8.712 8.600 8.678 2.585 1.251 ms 0.551 3.534

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 0.021 0.021 0.032 0.101 9.255 9.623 9.623 9.224 9.603 2.636 1.012 ms 0.6678 4.343

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 2001:470:0:50::2 (clock.fmt.he.net)

peer jitter 2001:470:0:50::2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 1.196 1.196 1.196 1.520 3.820 3.820 3.820 2.624 2.624 0.961 1.964 ms 5.53 15.89

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 2001:470:e815::24 (pi4.rellim.com)

peer jitter 2001:470:e815::24 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.422 0.422 0.422 1.671 12.380 12.380 12.380 11.957 11.957 4.214 4.071 ms 1.014 2.517

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 0.380 0.380 0.380 1.264 1.615 1.615 1.615 1.235 1.235 0.439 1.065 ms 6.688 15.13

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 2405:fc00:0:1::123

peer jitter 2405:fc00:0:1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2405:fc00:0:1::123 0.395 0.395 0.395 2.087 7.301 7.301 7.301 6.907 6.907 1.920 2.598 ms 2.13 5.576

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 2604:a880:1:20::17:5001 (ntp1.glypnod.com)

peer jitter 2604:a880:1:20::17:5001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.312 0.312 0.312 1.058 9.259 9.259 9.259 8.948 8.948 3.871 3.986 ms 0.4728 1.33

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 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com)

peer jitter 2a03:b0c0:1:d0::1f9:f001 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.333 0.333 0.333 0.723 8.849 8.849 8.849 8.517 8.517 2.902 1.965 ms 0.8656 2.805

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) 0.170 0.315 0.449 1.166 3.869 8.020 10.749 3.419 7.705 1.484 1.732 ms 2.821 11.87

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) 51.000 70.000 79.000 149.000 267.000 328.000 479.000 188.000 258.000 63.173 159.419 ns 9.187 31.06

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset -664.291 -664.154 -663.696 -657.257 -649.658 -649.200 -649.185 14.038 14.954 4.740 -656.749 ppb -2.718e+06 3.794e+08
Local Clock Time Offset -247.000 -77.000 3.000 243.000 504.000 572.000 616.000 501.000 649.000 146.119 245.097 ns 2.369 6.083
Local RMS Frequency Jitter 42.000 43.000 47.000 69.000 137.000 162.000 171.000 90.000 119.000 24.915 74.559 10e-12 15.64 59.63
Local RMS Time Jitter 85.000 90.000 99.000 144.000 188.000 201.000 215.000 89.000 111.000 28.004 143.589 ns 82.74 395.1
Server Jitter 192.168.1.11 0.034 0.034 0.048 0.144 8.648 8.712 8.712 8.600 8.678 2.585 1.251 ms 0.551 3.534
Server Jitter 192.168.1.12 0.021 0.021 0.032 0.101 9.255 9.623 9.623 9.224 9.603 2.636 1.012 ms 0.6678 4.343
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 1.196 1.196 1.196 1.520 3.820 3.820 3.820 2.624 2.624 0.961 1.964 ms 5.53 15.89
Server Jitter 2001:470:e815::24 (pi4.rellim.com) 0.422 0.422 0.422 1.671 12.380 12.380 12.380 11.957 11.957 4.214 4.071 ms 1.014 2.517
Server Jitter 216.218.254.202 0.380 0.380 0.380 1.264 1.615 1.615 1.615 1.235 1.235 0.439 1.065 ms 6.688 15.13
Server Jitter 2405:fc00:0:1::123 0.395 0.395 0.395 2.087 7.301 7.301 7.301 6.907 6.907 1.920 2.598 ms 2.13 5.576
Server Jitter 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 0.312 0.312 0.312 1.058 9.259 9.259 9.259 8.948 8.948 3.871 3.986 ms 0.4728 1.33
Server Jitter 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 0.333 0.333 0.333 0.723 8.849 8.849 8.849 8.517 8.517 2.902 1.965 ms 0.8656 2.805
Server Jitter SHM(0) 0.170 0.315 0.449 1.166 3.869 8.020 10.749 3.419 7.705 1.484 1.732 ms 2.821 11.87
Server Jitter SHM(1) 51.000 70.000 79.000 149.000 267.000 328.000 479.000 188.000 258.000 63.173 159.419 ns 9.187 31.06
Server Offset 192.168.1.11 -56.676 -56.676 -47.920 -11.293 74.271 76.941 76.941 122.191 133.617 34.517 -3.816 µs -3.842 7.939
Server Offset 192.168.1.12 -82.272 -82.272 -78.222 -41.888 49.910 77.113 77.113 128.132 159.385 36.855 -33.775 µs -11.39 29.13
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) 2.312 2.312 2.312 2.414 2.558 2.558 2.558 0.246 0.246 0.079 2.418 ms 2.591e+04 7.683e+05
Server Offset 2001:470:e815::24 (pi4.rellim.com) 3.927 3.927 3.927 4.266 4.600 4.600 4.600 0.673 0.673 0.203 4.311 ms 8288 1.685e+05
Server Offset 216.218.254.202 2.410 2.410 2.410 2.512 2.794 2.794 2.794 0.384 0.384 0.124 2.558 ms 7677 1.523e+05
Server Offset 2405:fc00:0:1::123 11.122 11.122 11.122 11.402 11.712 11.712 11.712 0.590 0.590 0.157 11.405 ms 3.652e+05 2.612e+07
Server Offset 2604:a880:1:20::17:5001 (ntp1.glypnod.com) 1.448 1.448 1.448 1.950 2.871 2.871 2.871 1.422 1.422 0.482 2.009 ms 41.98 171.6
Server Offset 2a03:b0c0:1:d0::1f9:f001 (ntp2.glypnod.com) 2.857 2.857 2.857 3.172 3.564 3.564 3.564 0.707 0.707 0.206 3.159 ms 2993 4.357e+04
Server Offset SHM(0) -68.039 -62.610 -58.510 -53.732 -49.334 -48.677 -47.351 9.176 13.933 2.620 -53.862 ms -1.008e+04 2.187e+05
Server Offset SHM(1) -248.000 -78.000 4.000 244.000 505.000 573.000 617.000 501.000 651.000 146.295 245.966 ns 2.379 6.112
TDOP 0.580 0.580 0.580 0.870 0.940 0.950 0.950 0.360 0.370 0.108 0.805 285.6 1949
Temp ZONE0 62.300 62.300 62.300 62.300 62.838 62.838 62.838 0.538 0.538 0.228 62.426 °C
nSats 9.000 9.000 9.000 10.000 12.000 12.000 12.000 3.000 3.000 0.744 10.344 nSat 2187 2.876e+04
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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