NTPsec

ntp03.maillink.ch

Report generated: Wed Apr 2 08:53:01 2025 UTC
Start Time: Tue Apr 1 08:53:01 2025 UTC
End Time: Wed Apr 2 08:53:01 2025 UTC
Report Period: 1.0 days

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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 -65.095 -49.798 -27.309 1.375 22.007 38.943 55.066 49.316 88.741 15.239 0.324 µs -4.592 15.06
Local Clock Frequency Offset -2.849 -2.846 -2.809 -2.748 -2.717 -2.712 -2.708 0.092 0.133 0.027 -2.752 ppm -1.109e+06 1.148e+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 1.965 2.516 3.332 6.580 18.140 31.547 40.535 14.808 29.031 5.158 7.962 µs 4.414 19.84

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 0.149 0.187 0.303 0.644 2.035 2.637 2.757 1.732 2.450 0.497 0.787 ppb 3.778 12.76

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 -65.095 -49.798 -27.309 1.375 22.007 38.943 55.066 49.316 88.741 15.239 0.324 µs -4.592 15.06

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 -2.849 -2.846 -2.809 -2.748 -2.717 -2.712 -2.708 0.092 0.133 0.027 -2.752 ppm -1.109e+06 1.148e+08
Temp ZONE0 50.700 50.700 51.800 53.450 55.100 55.650 55.650 3.300 4.950 0.919 53.621 °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 6.000 7.000 8.000 9.000 11.000 12.000 12.000 3.000 5.000 0.996 9.258 nSat 594.8 5139
TDOP 0.520 0.540 0.610 0.860 1.200 1.420 1.710 0.590 0.880 0.200 0.879 50.33 217.1

Local GPS. The Time Dilution of Precision (TDOP) is plotted in blue. The number of visible satellites (nSat) is plotted in red.

TDOP is field 3, and nSats is field 4, from the gpsd log file. The gpsd log file is created by the ntploggps program.

TDOP is a dimensionless error factor. Smaller numbers are better. TDOP ranges from 1 (ideal), 2 to 5 (good), to greater than 20 (poor). Some GNSS receivers report TDOP less than one which is theoretically impossible.



Server Offsets

peer offsets plot

The offset of all refclocks and servers. This can be useful to see if offset changes are happening in a single clock or all clocks together.

Clock Offset is field 5 in the peerstats log file.



Server Offset 195.176.26.206

peer offset 195.176.26.206 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 195.176.26.206 -130.037 -101.620 -78.088 -40.678 -1.909 15.549 54.484 76.179 117.169 23.408 -40.582 µs -28.66 105.4

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 2001:638:610:be01::103 (ptbtime3.ptb.de)

peer offset 2001:638:610:be01::103 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2001:638:610:be01::103 (ptbtime3.ptb.de) -2.823 -2.789 -2.753 -2.711 -2.657 -2.612 -2.579 0.096 0.177 0.033 -2.709 ms -5.965e+05 5.023e+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 2606:4700:f1::1 (time.cloudflare.com)

peer offset 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.638 0.645 0.675 1.057 1.238 1.275 1.286 0.564 0.630 0.202 0.962 ms 64.4 283.4

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 2606:4700:f1::123 (time.cloudflare.com)

peer offset 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 0.530 0.588 0.625 1.028 1.316 1.355 1.356 0.691 0.766 0.214 0.984 ms 56.94 241.8

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 2a00:d78:0:712:94:198:159:11 (nts1.time.nl)

peer offset 2a00:d78:0:712:94:198:159:11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) -215.750 -201.309 -177.045 -105.722 24.542 74.626 127.408 201.587 275.935 56.499 -99.682 µs -28.34 97.17

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 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se)

peer offset 2a01:3f7:2:44::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 3.944 4.294 4.321 4.372 4.419 4.438 4.456 0.098 0.143 0.045 4.368 ms 9.033e+05 8.734e+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 2a02:168:420b:4::7b:12 (ntp02.maillink.ch)

peer offset 2a02:168:420b:4::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) -57.926 -54.918 -37.201 -1.288 40.945 65.429 81.920 78.146 120.347 24.649 0.202 µs -3.706 8.802

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 2a02:168:420b:d::7b:12 (ntp01.maillink.ch)

peer offset 2a02:168:420b:d::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) -57.532 -40.901 -24.556 13.456 48.449 85.375 103.190 73.005 126.276 22.400 13.729 µs -0.918 4.983

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 85.195.224.28

peer offset 85.195.224.28 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset 85.195.224.28 -392.522 -362.707 -278.085 43.056 172.030 230.657 242.447 450.115 593.364 145.006 -5.085 µs -4.909 12.93

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 PPS(0)

peer offset PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset PPS(0) -53.244 -44.342 -22.338 7.315 32.035 57.557 72.744 54.373 101.899 16.247 6.781 µs -2.064 7.994

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) -633.423 -600.857 -497.831 -374.429 -328.518 -294.420 -17.887 169.313 306.437 61.840 -387.413 ms -405 3107

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(2)

peer offset SHM(2) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Offset SHM(2) -51.841 -46.122 -22.670 6.464 31.538 57.410 69.452 54.208 103.532 16.187 5.882 µs -2.265 8.477

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 195.176.26.206

peer jitter 195.176.26.206 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 195.176.26.206 12.728 16.631 23.158 67.065 236.401 560.485 1,123.229 213.243 543.854 115.291 100.338 µs 4.838 39.77

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 2001:638:610:be01::103 (ptbtime3.ptb.de)

peer jitter 2001:638:610:be01::103 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2001:638:610:be01::103 (ptbtime3.ptb.de) 18.254 18.724 29.839 68.970 300.516 385.251 500.863 270.677 366.527 81.852 99.289 µs 2.677 9.246

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 2606:4700:f1::1 (time.cloudflare.com)

peer jitter 2606:4700:f1::1 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 19.357 20.582 27.957 66.228 260.826 371.055 442.147 232.869 350.473 74.568 94.342 µs 2.899 10.45

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 2606:4700:f1::123 (time.cloudflare.com)

peer jitter 2606:4700:f1::123 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 26.030 27.576 36.148 78.967 362.181 813.599 964.057 326.033 786.023 124.777 117.219 µs 3.751 21.85

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 2a00:d78:0:712:94:198:159:11 (nts1.time.nl)

peer jitter 2a00:d78:0:712:94:198:159:11 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) 0.034 0.079 0.137 2.184 5.434 12.569 13.375 5.296 12.490 2.049 2.381 ms 2.972 14.23

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 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se)

peer jitter 2a01:3f7:2:44::8 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 17.236 25.575 30.958 78.579 296.298 474.356 3,312.192 265.340 448.781 261.134 134.419 µs 7.633 83.88

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 2a02:168:420b:4::7b:12 (ntp02.maillink.ch)

peer jitter 2a02:168:420b:4::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) 2.776 3.122 5.276 17.459 46.601 69.819 86.289 41.325 66.697 13.914 20.852 µs 3.006 9.736

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 2a02:168:420b:d::7b:12 (ntp01.maillink.ch)

peer jitter 2a02:168:420b:d::7b:12 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) 10.546 12.214 18.426 59.276 463.049 613.117 1,181.756 444.623 600.903 160.380 125.727 µs 2.28 12.91

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 85.195.224.28

peer jitter 85.195.224.28 plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter 85.195.224.28 13.910 16.532 23.150 74.002 318.438 706.492 1,158.899 295.288 689.960 138.280 121.478 µs 3.511 22.88

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 PPS(0)

peer jitter PPS(0) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter PPS(0) 0.093 0.391 0.881 1.862 3.262 4.742 26.085 2.381 4.351 0.819 1.939 µs 8.982 63.3

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) 3.397 4.891 7.656 26.430 108.052 207.354 388.863 100.396 202.464 41.145 38.859 ms 3.734 24.37

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(2)

peer jitter SHM(2) plot

Percentiles...... Ranges...... Skew- Kurt-
Name Min1%5%50%95% 99%Max   90%98%StdDev  MeanUnits nessosis
Server Jitter SHM(2) 0.162 0.518 1.038 5.517 18.361 29.757 36.423 17.323 29.239 5.932 7.165 µs 2.302 8.289

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 -2.849 -2.846 -2.809 -2.748 -2.717 -2.712 -2.708 0.092 0.133 0.027 -2.752 ppm -1.109e+06 1.148e+08
Local Clock Time Offset -65.095 -49.798 -27.309 1.375 22.007 38.943 55.066 49.316 88.741 15.239 0.324 µs -4.592 15.06
Local RMS Frequency Jitter 0.149 0.187 0.303 0.644 2.035 2.637 2.757 1.732 2.450 0.497 0.787 ppb 3.778 12.76
Local RMS Time Jitter 1.965 2.516 3.332 6.580 18.140 31.547 40.535 14.808 29.031 5.158 7.962 µs 4.414 19.84
Server Jitter 195.176.26.206 12.728 16.631 23.158 67.065 236.401 560.485 1,123.229 213.243 543.854 115.291 100.338 µs 4.838 39.77
Server Jitter 2001:638:610:be01::103 (ptbtime3.ptb.de) 18.254 18.724 29.839 68.970 300.516 385.251 500.863 270.677 366.527 81.852 99.289 µs 2.677 9.246
Server Jitter 2606:4700:f1::1 (time.cloudflare.com) 19.357 20.582 27.957 66.228 260.826 371.055 442.147 232.869 350.473 74.568 94.342 µs 2.899 10.45
Server Jitter 2606:4700:f1::123 (time.cloudflare.com) 26.030 27.576 36.148 78.967 362.181 813.599 964.057 326.033 786.023 124.777 117.219 µs 3.751 21.85
Server Jitter 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) 0.034 0.079 0.137 2.184 5.434 12.569 13.375 5.296 12.490 2.049 2.381 ms 2.972 14.23
Server Jitter 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 17.236 25.575 30.958 78.579 296.298 474.356 3,312.192 265.340 448.781 261.134 134.419 µs 7.633 83.88
Server Jitter 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) 2.776 3.122 5.276 17.459 46.601 69.819 86.289 41.325 66.697 13.914 20.852 µs 3.006 9.736
Server Jitter 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) 10.546 12.214 18.426 59.276 463.049 613.117 1,181.756 444.623 600.903 160.380 125.727 µs 2.28 12.91
Server Jitter 85.195.224.28 13.910 16.532 23.150 74.002 318.438 706.492 1,158.899 295.288 689.960 138.280 121.478 µs 3.511 22.88
Server Jitter PPS(0) 0.093 0.391 0.881 1.862 3.262 4.742 26.085 2.381 4.351 0.819 1.939 µs 8.982 63.3
Server Jitter SHM(0) 3.397 4.891 7.656 26.430 108.052 207.354 388.863 100.396 202.464 41.145 38.859 ms 3.734 24.37
Server Jitter SHM(2) 0.162 0.518 1.038 5.517 18.361 29.757 36.423 17.323 29.239 5.932 7.165 µs 2.302 8.289
Server Offset 195.176.26.206 -130.037 -101.620 -78.088 -40.678 -1.909 15.549 54.484 76.179 117.169 23.408 -40.582 µs -28.66 105.4
Server Offset 2001:638:610:be01::103 (ptbtime3.ptb.de) -2.823 -2.789 -2.753 -2.711 -2.657 -2.612 -2.579 0.096 0.177 0.033 -2.709 ms -5.965e+05 5.023e+07
Server Offset 2606:4700:f1::1 (time.cloudflare.com) 0.638 0.645 0.675 1.057 1.238 1.275 1.286 0.564 0.630 0.202 0.962 ms 64.4 283.4
Server Offset 2606:4700:f1::123 (time.cloudflare.com) 0.530 0.588 0.625 1.028 1.316 1.355 1.356 0.691 0.766 0.214 0.984 ms 56.94 241.8
Server Offset 2a00:d78:0:712:94:198:159:11 (nts1.time.nl) -215.750 -201.309 -177.045 -105.722 24.542 74.626 127.408 201.587 275.935 56.499 -99.682 µs -28.34 97.17
Server Offset 2a01:3f7:2:44::8 (sth1-ts.nts.netnod.se) 3.944 4.294 4.321 4.372 4.419 4.438 4.456 0.098 0.143 0.045 4.368 ms 9.033e+05 8.734e+07
Server Offset 2a02:168:420b:4::7b:12 (ntp02.maillink.ch) -57.926 -54.918 -37.201 -1.288 40.945 65.429 81.920 78.146 120.347 24.649 0.202 µs -3.706 8.802
Server Offset 2a02:168:420b:d::7b:12 (ntp01.maillink.ch) -57.532 -40.901 -24.556 13.456 48.449 85.375 103.190 73.005 126.276 22.400 13.729 µs -0.918 4.983
Server Offset 85.195.224.28 -392.522 -362.707 -278.085 43.056 172.030 230.657 242.447 450.115 593.364 145.006 -5.085 µs -4.909 12.93
Server Offset PPS(0) -53.244 -44.342 -22.338 7.315 32.035 57.557 72.744 54.373 101.899 16.247 6.781 µs -2.064 7.994
Server Offset SHM(0) -633.423 -600.857 -497.831 -374.429 -328.518 -294.420 -17.887 169.313 306.437 61.840 -387.413 ms -405 3107
Server Offset SHM(2) -51.841 -46.122 -22.670 6.464 31.538 57.410 69.452 54.208 103.532 16.187 5.882 µs -2.265 8.477
TDOP 0.520 0.540 0.610 0.860 1.200 1.420 1.710 0.590 0.880 0.200 0.879 50.33 217.1
Temp ZONE0 50.700 50.700 51.800 53.450 55.100 55.650 55.650 3.300 4.950 0.919 53.621 °C
nSats 6.000 7.000 8.000 9.000 11.000 12.000 12.000 3.000 5.000 0.996 9.258 nSat 594.8 5139
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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