NTPsec

ntp.as397444.net

Report generated: Sun May 28 13:01:17 2023 UTC
Start Time: Sun May 21 13:01:05 2023 UTC
End Time: Sun May 28 13:01:05 2023 UTC
Report Period: 7.0 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 -9.000 -3.000 -2.000 0.000 2.000 3.000 22.000 4.000 6.000 1.215 -0.001 ns -1.884 20.75
Local Clock Frequency Offset 19.622 19.646 19.694 20.017 20.350 20.529 20.554 0.656 0.883 0.195 20.017 ppm 1.046e+06 1.062e+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 1.000 15.000 21.000 36.000 56.000 67.000 99.000 35.000 52.000 10.563 37.166 ns 24.1 88.06

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 0.000 0.000 0.000 0.000 0.000 0.000 3,000.000 0.000 0.000 91.841 7.762 10e-12 9.144 139.7

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 -9.000 -3.000 -2.000 0.000 2.000 3.000 22.000 4.000 6.000 1.215 -0.001 ns -1.884 20.75

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 19.622 19.646 19.694 20.017 20.350 20.529 20.554 0.656 0.883 0.195 20.017 ppm 1.046e+06 1.062e+08
Temp LM0 51.875 52.375 52.500 53.750 55.625 56.500 57.000 3.125 4.125 0.939 53.914 °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 11.000 15.000 16.000 20.000 25.000 26.000 30.000 9.000 11.000 2.542 20.354 nSat 365.3 2713
TDOP 0.180 0.190 0.190 0.210 0.230 0.240 0.270 0.040 0.050 0.012 0.211 5112 8.869e+04

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.



Refclock Offset 127.127.20.1 NMEA(1)

peer offset 127.127.20.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock Offset 127.127.20.1 NMEA(1) -20.140 -7.432 -4.773 3.587 10.380 11.890 16.160 15.153 19.322 5.153 3.294 ms -1.31 2.912

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

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local serial GPS 200 ms; local PPS 20µs.

Clock Offset is field 5 in the peerstats log file.



Refclock Offset 127.127.20.2 NMEA(2)

peer offset 127.127.20.2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock Offset 127.127.20.2 NMEA(2) -31.300 -7.911 -5.417 0.963 7.138 9.224 14.300 12.555 17.135 3.846 0.947 ms -2.807 6.982

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

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local serial GPS 200 ms; local PPS 20µs.

Clock Offset is field 5 in the peerstats log file.



Refclock Offset 127.127.20.3 NMEA(3)

peer offset 127.127.20.3 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock Offset 127.127.20.3 NMEA(3) -109.400 -84.740 -73.150 -26.020 16.150 23.080 41.130 89.300 107.820 30.119 -26.776 ms -12.52 36.69

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

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local serial GPS 200 ms; local PPS 20µs.

Clock Offset is field 5 in the peerstats log file.



Refclock Offset 127.127.46.1 GPS(1)

peer offset 127.127.46.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock Offset 127.127.46.1 GPS(1) -36.000 -18.000 -9.000 10.000 29.000 37.000 69.000 38.000 55.000 11.524 10.020 ns -0.3708 3.412

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

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local serial GPS 200 ms; local PPS 20µs.

Clock Offset is field 5 in the peerstats log file.



Refclock Offset 127.127.46.2 GPS(2)

peer offset 127.127.46.2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock Offset 127.127.46.2 GPS(2) -112.000 -80.000 -69.000 -45.000 -23.000 -12.000 20.000 46.000 68.000 13.869 -45.013 ns -89.42 439.5

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

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local serial GPS 200 ms; local PPS 20µs.

Clock Offset is field 5 in the peerstats log file.



Refclock Offset 127.127.46.3 GPS(3)

peer offset 127.127.46.3 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock Offset 127.127.46.3 GPS(3) -9.000 13.000 19.000 35.000 52.000 60.000 81.000 33.000 47.000 10.112 35.049 ns 22.63 79.16

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

Closer to 0s is better. An ideal system would be a horizontal line at 0s. Typical 90% ranges may be: local serial GPS 200 ms; local PPS 20µs.

Clock Offset is field 5 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 -6.856 -4.099 -3.433 -2.958 -2.497 -2.123 -1.852 0.936 1.976 0.345 -2.954 ms -905.7 9052

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

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

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

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



Server Offset 169.229.128.134

peer offset 169.229.128.134 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 169.229.128.134 -885.500 -483.000 -137.500 238.400 599.000 947.400 1,257.000 736.500 1,430.400 232.754 233.332 µs -0.2917 6.295

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) -481.800 -281.200 -137.200 -4.660 349.600 701.800 988.000 486.800 983.000 167.441 40.826 µs -1.013 6.81

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 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu)

peer offset 2607:f140:ffff:8000:0:8006:0:a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) -164.700 -46.560 36.960 207.700 554.900 858.200 1,325.000 517.940 904.760 173.814 241.065 µs 3.126 13.76

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 2610:20:6f96:96::4 (time-d-b.nist.gov)

peer offset 2610:20:6f96:96::4 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2610:20:6f96:96::4 (time-d-b.nist.gov) -1.742 -1.154 -0.814 -0.166 0.322 0.723 0.970 1.136 1.877 0.346 -0.193 ms -8.728 26.5

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 2610:20:6f97:97::6 (time-e-wwv.nist.gov)

peer offset 2610:20:6f97:97::6 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2610:20:6f97:97::6 (time-e-wwv.nist.gov) -0.921 -0.733 -0.335 0.223 0.842 1.249 1.378 1.176 1.982 0.372 0.228 ms -1.044 4.306

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 PPS1

peer offset PPS1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset PPS1 -94.810 -29.780 -16.190 7.898 36.440 58.130 107.300 52.630 87.910 16.294 8.370 µs -1.117 5.493

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.



Refclock RMS Jitter 127.127.20.1 NMEA(1)

peer jitter 127.127.20.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock RMS Jitter 127.127.20.1 NMEA(1) 0.016 0.263 0.412 1.104 2.739 3.537 13.840 2.327 3.274 0.769 1.301 ms 3.899 15.36

The RMS Jitter of a local refclock. 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.



Refclock RMS Jitter 127.127.20.2 NMEA(2)

peer jitter 127.127.20.2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock RMS Jitter 127.127.20.2 NMEA(2) 0.057 0.654 0.970 1.578 2.296 2.873 11.350 1.326 2.219 0.430 1.604 ms 29.85 125.4

The RMS Jitter of a local refclock. 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.



Refclock RMS Jitter 127.127.20.3 NMEA(3)

peer jitter 127.127.20.3 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock RMS Jitter 127.127.20.3 NMEA(3) 0.016 0.225 0.355 0.978 2.009 2.717 23.360 1.654 2.492 1.182 1.106 ms 11.23 159.2

The RMS Jitter of a local refclock. 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.



Refclock RMS Jitter 127.127.46.1 GPS(1)

peer jitter 127.127.46.1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock RMS Jitter 127.127.46.1 GPS(1) 1.000 2.000 2.000 3.000 5.000 9.000 51.000 3.000 7.000 1.783 3.428 ns 11.09 127.8

The RMS Jitter of a local refclock. 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.



Refclock RMS Jitter 127.127.46.2 GPS(2)

peer jitter 127.127.46.2 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock RMS Jitter 127.127.46.2 GPS(2) 2.000 2.000 3.000 4.000 6.000 9.000 53.000 3.000 7.000 1.776 4.229 ns 13.83 142.3

The RMS Jitter of a local refclock. 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.



Refclock RMS Jitter 127.127.46.3 GPS(3)

peer jitter 127.127.46.3 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Refclock RMS Jitter 127.127.46.3 GPS(3) 1.000 1.000 1.000 2.000 5.000 9.000 53.000 4.000 8.000 1.975 2.606 ns 7.819 89.17

The RMS Jitter of a local refclock. 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 23.420 48.120 73.250 199.500 436.600 576.700 750.000 363.350 528.580 112.872 221.557 µs 4.952 15.95

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 169.229.128.134

peer jitter 169.229.128.134 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 169.229.128.134 44.060 64.340 103.600 197.600 315.600 453.600 616.100 212.000 389.260 74.122 205.296 µs 12.09 44.51

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) 5.841 9.602 18.730 78.860 248.500 316.200 374.500 229.770 306.598 74.825 103.591 µs 2.14 5.382

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 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu)

peer jitter 2607:f140:ffff:8000:0:8006:0:a plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 3.972 16.500 29.360 75.820 238.600 306.300 339.200 209.240 289.800 70.494 105.796 µs 2.53 6.329

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 2610:20:6f96:96::4 (time-d-b.nist.gov)

peer jitter 2610:20:6f96:96::4 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2610:20:6f96:96::4 (time-d-b.nist.gov) 88.610 174.700 225.400 338.800 536.200 581.300 621.900 310.800 406.600 95.099 357.270 µs 29.67 111.1

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 2610:20:6f97:97::6 (time-e-wwv.nist.gov)

peer jitter 2610:20:6f97:97::6 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2610:20:6f97:97::6 (time-e-wwv.nist.gov) 41.220 114.700 176.100 299.300 472.900 603.200 817.400 296.800 488.500 100.355 313.925 µs 16.63 56.82

The RMS Jitter of a server. Jitter is the current estimated dispersion, in other words the variation in offset between samples.

Closer to 0s is better. An ideal system would be a horizontal line at 0s.

RMS Jitter is field 8 in the peerstats log file.



Server Jitter PPS1

peer jitter PPS1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter PPS1 0.076 0.623 26.910 39.520 47.590 53.430 90.920 20.680 52.807 7.807 38.591 µs 70.88 311.7

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.



Summary


Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Local Clock Frequency Offset 19.622 19.646 19.694 20.017 20.350 20.529 20.554 0.656 0.883 0.195 20.017 ppm 1.046e+06 1.062e+08
Local Clock Time Offset -9.000 -3.000 -2.000 0.000 2.000 3.000 22.000 4.000 6.000 1.215 -0.001 ns -1.884 20.75
Local RMS Frequency Jitter 0.000 0.000 0.000 0.000 0.000 0.000 3,000.000 0.000 0.000 91.841 7.762 10e-12 9.144 139.7
Local RMS Time Jitter 1.000 15.000 21.000 36.000 56.000 67.000 99.000 35.000 52.000 10.563 37.166 ns 24.1 88.06
Refclock Offset 127.127.20.1 NMEA(1) -20.140 -7.432 -4.773 3.587 10.380 11.890 16.160 15.153 19.322 5.153 3.294 ms -1.31 2.912
Refclock Offset 127.127.20.2 NMEA(2) -31.300 -7.911 -5.417 0.963 7.138 9.224 14.300 12.555 17.135 3.846 0.947 ms -2.807 6.982
Refclock Offset 127.127.20.3 NMEA(3) -109.400 -84.740 -73.150 -26.020 16.150 23.080 41.130 89.300 107.820 30.119 -26.776 ms -12.52 36.69
Refclock Offset 127.127.46.1 GPS(1) -36.000 -18.000 -9.000 10.000 29.000 37.000 69.000 38.000 55.000 11.524 10.020 ns -0.3708 3.412
Refclock Offset 127.127.46.2 GPS(2) -112.000 -80.000 -69.000 -45.000 -23.000 -12.000 20.000 46.000 68.000 13.869 -45.013 ns -89.42 439.5
Refclock Offset 127.127.46.3 GPS(3) -9.000 13.000 19.000 35.000 52.000 60.000 81.000 33.000 47.000 10.112 35.049 ns 22.63 79.16
Refclock RMS Jitter 127.127.20.1 NMEA(1) 0.016 0.263 0.412 1.104 2.739 3.537 13.840 2.327 3.274 0.769 1.301 ms 3.899 15.36
Refclock RMS Jitter 127.127.20.2 NMEA(2) 0.057 0.654 0.970 1.578 2.296 2.873 11.350 1.326 2.219 0.430 1.604 ms 29.85 125.4
Refclock RMS Jitter 127.127.20.3 NMEA(3) 0.016 0.225 0.355 0.978 2.009 2.717 23.360 1.654 2.492 1.182 1.106 ms 11.23 159.2
Refclock RMS Jitter 127.127.46.1 GPS(1) 1.000 2.000 2.000 3.000 5.000 9.000 51.000 3.000 7.000 1.783 3.428 ns 11.09 127.8
Refclock RMS Jitter 127.127.46.2 GPS(2) 2.000 2.000 3.000 4.000 6.000 9.000 53.000 3.000 7.000 1.776 4.229 ns 13.83 142.3
Refclock RMS Jitter 127.127.46.3 GPS(3) 1.000 1.000 1.000 2.000 5.000 9.000 53.000 4.000 8.000 1.975 2.606 ns 7.819 89.17
Server Jitter 162.159.200.123 23.420 48.120 73.250 199.500 436.600 576.700 750.000 363.350 528.580 112.872 221.557 µs 4.952 15.95
Server Jitter 169.229.128.134 44.060 64.340 103.600 197.600 315.600 453.600 616.100 212.000 389.260 74.122 205.296 µs 12.09 44.51
Server Jitter 2001:470:0:50::2 (clock.fmt.he.net) 5.841 9.602 18.730 78.860 248.500 316.200 374.500 229.770 306.598 74.825 103.591 µs 2.14 5.382
Server Jitter 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) 3.972 16.500 29.360 75.820 238.600 306.300 339.200 209.240 289.800 70.494 105.796 µs 2.53 6.329
Server Jitter 2610:20:6f96:96::4 (time-d-b.nist.gov) 88.610 174.700 225.400 338.800 536.200 581.300 621.900 310.800 406.600 95.099 357.270 µs 29.67 111.1
Server Jitter 2610:20:6f97:97::6 (time-e-wwv.nist.gov) 41.220 114.700 176.100 299.300 472.900 603.200 817.400 296.800 488.500 100.355 313.925 µs 16.63 56.82
Server Jitter PPS1 0.076 0.623 26.910 39.520 47.590 53.430 90.920 20.680 52.807 7.807 38.591 µs 70.88 311.7
Server Offset 162.159.200.123 -6.856 -4.099 -3.433 -2.958 -2.497 -2.123 -1.852 0.936 1.976 0.345 -2.954 ms -905.7 9052
Server Offset 169.229.128.134 -885.500 -483.000 -137.500 238.400 599.000 947.400 1,257.000 736.500 1,430.400 232.754 233.332 µs -0.2917 6.295
Server Offset 2001:470:0:50::2 (clock.fmt.he.net) -481.800 -281.200 -137.200 -4.660 349.600 701.800 988.000 486.800 983.000 167.441 40.826 µs -1.013 6.81
Server Offset 2607:f140:ffff:8000:0:8006:0:a (ntp1.net.berkeley.edu) -164.700 -46.560 36.960 207.700 554.900 858.200 1,325.000 517.940 904.760 173.814 241.065 µs 3.126 13.76
Server Offset 2610:20:6f96:96::4 (time-d-b.nist.gov) -1.742 -1.154 -0.814 -0.166 0.322 0.723 0.970 1.136 1.877 0.346 -0.193 ms -8.728 26.5
Server Offset 2610:20:6f97:97::6 (time-e-wwv.nist.gov) -0.921 -0.733 -0.335 0.223 0.842 1.249 1.378 1.176 1.982 0.372 0.228 ms -1.044 4.306
Server Offset PPS1 -94.810 -29.780 -16.190 7.898 36.440 58.130 107.300 52.630 87.910 16.294 8.370 µs -1.117 5.493
TDOP 0.180 0.190 0.190 0.210 0.230 0.240 0.270 0.040 0.050 0.012 0.211 5112 8.869e+04
Temp LM0 51.875 52.375 52.500 53.750 55.625 56.500 57.000 3.125 4.125 0.939 53.914 °C
nSats 11.000 15.000 16.000 20.000 25.000 26.000 30.000 9.000 11.000 2.542 20.354 nSat 365.3 2713
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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