Hi Dennis, First, my setup description was wrong, so please let me update it:
Master <--> Slave (with embedded KSZ switch) - Master is using HW timestamps. - Slave has an embedded ptp switch (KSZ9477) which provides the Slave device HW timestamps. Now, as for the output: ptp4l[13912.339]: selected /dev/ptp1 as PTP clock ptp4l[13912.341]: port 1: INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[13912.342]: port 0: INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[13912.344]: version=2 ports=3 ptp4l[13912.344]: access_delay=63000 ptp4l[13912.344]: UTC offset: 37 ptp4l[13912.345]: port 1: link up ptp4l[13915.030]: port 1: new foreign master f44d30.fffe.63e12b-1 ptp4l[13919.030]: selected best master clock f44d30.fffe.63e12b ptp4l[13919.030]: port 1: LISTENING to UNCALIBRATED on RS_SLAVE ptp4l[13919.905]: port 1: UNCALIBRATED to SLAVE on MASTER_CLOCK_SELECTED ptp4l[13935.281]: rms 2076 max 8052 freq -17397 +/- 2087 delay 7989 +/- 138 ptp4l[13951.283]: rms 54 max 162 freq -16924 +/- 59 delay 7474 +/- 21 ptp4l[13967.285]: rms 14 max 48 freq -16947 +/- 9 delay 7455 +/- 5 ptp4l[13983.287]: rms 11 max 30 freq -16948 +/- 7 delay 7452 +/- 5 ptp4l[13999.289]: rms 11 max 28 freq -16952 +/- 10 delay 7438 +/- 7 ptp4l[14015.290]: rms 68 max 136 freq -16883 +/- 67 delay 7434 +/- 7 ptp4l[14031.292]: rms 75 max 159 freq -16911 +/- 80 delay 7453 +/- 3 ptp4l[14047.294]: rms 46 max 116 freq -16940 +/- 47 delay 7449 +/- 3 ptp4l[14063.295]: rms 39 max 106 freq -16940 +/- 41 delay 7453 +/- 3 ptp4l[14079.297]: rms 36 max 105 freq -16935 +/- 40 delay 7455 +/- 1 ptp4l[14095.299]: rms 37 max 94 freq -16934 +/- 41 delay 7449 +/- 4 ptp4l[14111.301]: rms 84 max 160 freq -16894 +/- 102 delay 7446 +/- 1 ptp4l[14127.303]: rms 60 max 119 freq -16888 +/- 74 delay 7446 +/- 1 ptp4l[14143.305]: rms 40 max 102 freq -16858 +/- 37 delay 7447 +/- 4 ptp4l[14159.307]: rms 54 max 141 freq -16864 +/- 73 delay 7454 +/- 4 ptp4l[14175.309]: rms 28 max 73 freq -16849 +/- 23 delay 7457 +/- 4 ptp4l[14191.310]: rms 16 max 46 freq -16849 +/- 16 delay 7456 +/- 3 ptp4l[14207.312]: rms 10 max 24 freq -16841 +/- 8 delay 7449 +/- 4 ptp4l[14223.314]: rms 26 max 93 freq -16857 +/- 31 delay 7439 +/- 2 ptp4l[14239.316]: rms 70 max 141 freq -16917 +/- 79 delay 7443 +/- 4 ptp4l[14255.318]: rms 52 max 158 freq -16888 +/- 71 delay 7452 +/- 6 ptp4l[14271.320]: rms 73 max 152 freq -16863 +/- 70 delay 7446 +/- 5 ptp4l[14287.321]: rms 47 max 114 freq -16861 +/- 55 delay 7456 +/- 1 ptp4l[14303.323]: rms 38 max 111 freq -16862 +/- 41 delay 7460 +/- 3 ptp4l[14319.325]: rms 31 max 93 freq -16864 +/- 34 delay 7463 +/- 3 ptp4l[14335.327]: rms 61 max 121 freq -16878 +/- 60 delay 7449 +/- 4 *---------------------- Till here, no traffic, only ptp messages ------------------------- * *---------------------------------- Here I start the traffic --------------------------------- * ptp4l[14368.081]: rms 63 max 128 freq -16922 +/- 73 delay 7437 +/- 0 ptp4l[14384.084]: rms 19 max 58 freq -16911 +/- 16 ptp4l[14400.087]: rms 10 max 26 freq -16958 +/- 14 delay 7437 +/- 0 ptp4l[14416.089]: rms 11 max 28 freq -16997 +/- 12 delay 7437 +/- 0 ptp4l[14432.092]: rms 11 max 24 freq -17030 +/- 10 ptp4l[14448.094]: rms 11 max 26 freq -17062 +/- 11 ptp4l[14464.097]: rms 10 max 24 freq -17089 +/- 10 ptp4l[14480.099]: rms 11 max 28 freq -17105 +/- 7 delay 7437 +/- 0 ptp4l[14496.102]: rms 11 max 24 freq -17123 +/- 8 ptp4l[14512.104]: rms 28 max 67 freq -17112 +/- 29 delay 7437 +/- 0 ptp4l[14528.106]: rms 17 max 61 freq -17121 +/- 16 delay 7434 +/- 1 ptp4l[14544.111]: rms 37 max 80 freq -17085 +/- 38 delay 7435 +/- 0 ptp4l[14560.112]: rms 26 max 66 freq -17055 +/- 27 delay 7433 +/- 0 ptp4l[14576.115]: rms 11 max 32 freq -17043 +/- 9 ptp4l[14592.116]: rms 10 max 25 freq -17035 +/- 7 delay 7433 +/- 0 ptp4l[14608.119]: rms 10 max 21 freq -17029 +/- 6 ptp4l[14624.122]: rms 12 max 31 freq -17031 +/- 8 delay 7433 +/- 0 ptp4l[14640.127]: rms 10 max 22 freq -17023 +/- 9 ptp4l[14656.127]: rms 10 max 23 freq -17015 +/- 7 delay 7433 +/- 0 ptp4l[14672.130]: rms 20 max 76 freq -17026 +/- 17 delay 7428 +/- 0 ptp4l[14688.132]: rms 49 max 119 freq -17019 +/- 51 delay 7433 +/- 0 ptp4l[14704.135]: rms 54 max 137 freq -16944 +/- 69 ptp4l[14720.137]: rms 37 max 104 freq -16925 +/- 39 delay 7435 +/- 0 ptp4l[14736.140]: rms 10 max 23 freq -16911 +/- 7 delay 7435 +/- 0 ptp4l[14752.143]: rms 10 max 21 freq -16896 +/- 10 ptp4l[14768.148]: rms 11 max 26 freq -16885 +/- 7 delay 7430 +/- 2 ptp4l[14784.148]: rms 11 max 26 freq -16893 +/- 8 delay 7428 +/- 0 ptp4l[14800.150]: rms 10 max 30 freq -16883 +/- 9 delay 7428 +/- 0 ptp4l[14816.152]: rms 10 max 26 freq -16870 +/- 7 delay 7419 +/- 0 ptp4l[14832.155]: rms 10 max 21 freq -16864 +/- 6 delay 7419 +/- 0 ptp4l[14848.157]: rms 10 max 24 freq -16859 +/- 7 ptp4l[14864.159]: rms 10 max 22 freq -16849 +/- 10 delay 7419 +/- 0 ptp4l[14880.163]: rms 11 max 27 freq -16838 +/- 8 delay 7413 +/- 0 ptp4l[14896.167]: rms 11 max 26 freq -16839 +/- 8 delay 7419 +/- 0 ptp4l[14912.167]: rms 11 max 28 freq -16845 +/- 8 ptp4l[14928.171]: rms 10 max 29 freq -16847 +/- 6 ptp4l[14944.172]: rms 11 max 25 freq -16846 +/- 7 ptp4l[14960.175]: rms 10 max 24 freq -16847 +/- 6 ptp4l[14976.176]: rms 10 max 27 freq -16851 +/- 7 ptp4l[14992.179]: rms 19 max 64 freq -16855 +/- 18 delay 7357 +/- 0 ptp4l[15008.182]: rms 27 max 88 freq -16847 +/- 28 delay 7357 +/- 0 ptp4l[15024.191]: rms 13 max 42 freq -16852 +/- 10 ptp4l[15040.188]: rms 11 max 23 freq -16847 +/- 7 delay 7357 +/- 0 ptp4l[15056.192]: rms 10 max 27 freq -16845 +/- 7 delay 7357 +/- 0 *ptp4l[15072.192]: rms 10 max 26 freq -16832 +/- 7* *---------------------------------- Here the delay is getting smaller somehow --------------------------------- * *ptp4l[15088.195]: rms 628 max 2478 freq -16660 +/- 630 delay 4879 +/- 0* ptp4l[15104.198]: rms 44 max 162 freq -16834 +/- 40 delay 4879 +/- 0 ptp4l[15120.200]: rms 11 max 23 freq -16827 +/- 7 ptp4l[15136.203]: rms 44 max 167 freq -16812 +/- 44 delay 4790 +/- 89 ptp4l[15152.207]: rms 121 max 470 freq -16785 +/- 120 delay 4231 +/- 0 ptp4l[15168.208]: rms 12 max 30 freq -16821 +/- 8 delay 4231 +/- 0 ptp4l[15184.214]: rms 10 max 25 freq -16825 +/- 6 ptp4l[15200.215]: rms 10 max 22 freq -16825 +/- 6 ptp4l[15216.215]: rms 11 max 26 freq -16829 +/- 6 ptp4l[15232.217]: rms 11 max 26 freq -16832 +/- 8 delay 4231 +/- 0 ptp4l[15248.220]: rms 175 max 945 freq -16744 +/- 201 delay 3299 +/- 0 ptp4l[15264.223]: rms 643 max 2521 freq -16663 +/- 631 delay 2060 +/- 1238 ptp4l[15280.227]: rms 159 max 455 freq -16836 +/- 169 ptp4l[15296.227]: rms 46 max 113 freq -16812 +/- 52 ptp4l[15312.231]: rms 30 max 106 freq -16816 +/- 36 delay 822 +/- 0 ptp4l[15328.232]: rms 56 max 132 freq -16799 +/- 66 delay 822 +/- 0 ptp4l[15344.235]: rms 59 max 135 freq -16808 +/- 63 ptp4l[15360.237]: rms 13 max 56 freq -16823 +/- 10 delay 821 +/- 0 ptp4l[15376.240]: rms 38 max 104 freq -16818 +/- 41 ptp4l[15392.243]: rms 46 max 113 freq -16814 +/- 50 delay 821 +/- 0 ptp4l[15408.246]: rms 10 max 21 freq -16825 +/- 6 ptp4l[15424.247]: rms 58 max 146 freq -16810 +/- 69 ptp4l[15440.250]: rms 15 max 45 freq -16829 +/- 12 ptp4l[15456.252]: rms 37 max 118 freq -16791 +/- 69 delay 821 +/- 0 ptp4l[15472.255]: rms 62 max 151 freq -16754 +/- 65 delay 821 +/- 0 ptp4l[15488.257]: rms 47 max 102 freq -16754 +/- 67 delay 821 +/- 0 ptp4l[15504.259]: rms 23 max 54 freq -16722 +/- 22 delay 821 +/- 0 *ptp4l[15520.262]: rms 70 max 129 freq -16757 +/- 71 delay 821 +/- 0* *---------------------------------- Here I stop the traffic --------------------------------- * *ptp4l[15536.263]: rms 875 max 2463 freq -17147 +/- 918 delay 5696 +/- 1494* *ptp4l[15552.264]: rms 166 max 490 freq -16802 +/- 117 delay 7433 +/- 3* ptp4l[15568.266]: rms 12 max 26 freq -16741 +/- 13 delay 7442 +/- 5 ptp4l[15584.267]: rms 11 max 28 freq -16711 +/- 10 delay 7455 +/- 2 ptp4l[15600.269]: rms 15 max 62 freq -16707 +/- 13 delay 7448 +/- 6 ptp4l[15616.270]: rms 62 max 134 freq -16759 +/- 64 delay 7440 +/- 2 ptp4l[15632.272]: rms 18 max 47 freq -16831 +/- 18 delay 7444 +/- 2 ptp4l[15648.273]: rms 10 max 23 freq -16833 +/- 7 delay 7444 +/- 5 ptp4l[15664.275]: rms 11 max 29 freq -16833 +/- 9 delay 7451 +/- 6 ptp4l[15680.276]: rms 30 max 73 freq -16843 +/- 30 delay 7452 +/- 3 ptp4l[15696.278]: rms 36 max 81 freq -16871 +/- 37 delay 7450 +/- 4 ptp4l[15712.280]: rms 15 max 39 freq -16871 +/- 13 delay 7449 +/- 6 ptp4l[15728.281]: rms 12 max 35 freq -16880 +/- 8 delay 7452 +/- 6 On Fri, Jun 4, 2021 at 12:27 PM Dennis Hagarty (dehagart) < dehag...@cisco.com> wrote: > Hi Joseph, > > > > Do you have any output showing it? > > > > I might have an explanation :-) > > But I need to test my theory against your data. > > > > Regards > > Dennis > > > > *From:* Joseph Matan <joseph.matan...@gmail.com> > *Sent:* Thursday, 03 June 2021 21:18 > *To:* linuxptp-users@lists.sourceforge.net > *Subject:* [Linuxptp-users] Path delay is getting smaller under heavy > traffic > > > > Hi all, > > > > This is my simple setup: > > master <--> switch <--> slave > > The switch is not a ptp-aware. > > > > When there is only ptp traffic, the path delay is almost constant (very > low jitter). > > The weird thing (to me anyway...) is that under heavy traffic the path > delay is getting smaller - how does that make sense? > > If the switch is not ptp-aware I was expecting the path delay to get > bigger. > > > > Does anyone have a good explanation for this behavior ? > > > > Thanks, > > Joseph >
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