LinuxPTP synchronisation drifts when starting gnb #1216

jshacke · 2025-05-20T15:05:55Z

jshacke
May 20, 2025

I'm having an issue with our 7.2 configuration using Benetel 650 and FibroLAN RX GM Switch; where upon starting the gnb my ptp4l and phc2sys start to fluctuate wildly. It doesn't appear that the 650 is broadcasting, and I cannot see the network on UE and no C/U plane traffic is coming (from RU logs)

Has anyone had any experience with this?

Answered by jshacke

Jun 2, 2025

Closing: hardware issue, was NIC related. Replaced with Intel 82599ES and PTP functions as expected

View full answer

VikrantDigiCat · 2025-05-28T09:30:27Z

VikrantDigiCat
May 28, 2025

Hi @jshacke
can you please check below parameters and their corresponding values in the ptp config file that you are using?
domainNumber 24
tx_timestamp_timeout 100

Though im still struggling to get my srsRAN system to work but i also had several issues in getting PTP to work in the first place.
Let me know if this helps.

3 replies

jshacke May 28, 2025
Author

@VikrantDigiCat Thanks for getting in touch, domainNumber was already set to 24, changed my tx_timestamp_timeout from 20 to 100 as per your suggestion but rms didn't improve. RMS values fluctuate between 30 to 80. I have attached my linuxptp config file for reference.

default.txt

VikrantDigiCat May 28, 2025

@jshacke your config looks ok. Here is mine, in case it helps.
default.txt

Are you having issue on ORU or gNodeB regarding ptp sync?

jshacke May 29, 2025
Author

Thanks, likewise.

gNodeB, I'm getting various warnings about late downlink C-Plane and U-Plane messages in the transmitter queue. UE doesn't see the network.

VikrantDigiCat · 2025-05-28T09:40:01Z

VikrantDigiCat
May 28, 2025

@jshacke below is the output of my ptp4l/phc2sys running as service in the background. I'm using Falcon RX812 as the gM.

May 28 09:35:35 lon5g-sp-33 ptp4l[94065]: ptp4l[71485.930]: rms    2 max    4 freq  -6671 +/-   3 delay    12 +/-   1
May 28 09:35:35 lon5g-sp-33 ptp4l: [71485.930] rms    2 max    4 freq  -6671 +/-   3 delay    12 +/-   1
May 28 09:35:35 lon5g-sp-33 phc2sys[1029]: phc2sys[71486.021]: CLOCK_REALTIME phc offset        -4 s2 freq  +12355 delay    565
May 28 09:35:35 lon5g-sp-33 phc2sys: [71486.021] CLOCK_REALTIME phc offset        -4 s2 freq  +12355 delay    565
May 28 09:35:35 lon5g-sp-33 phc2sys[1029]: phc2sys[71486.147]: CLOCK_REALTIME phc offset        25 s2 freq  +12383 delay    511
May 28 09:35:35 lon5g-sp-33 phc2sys: [71486.147] CLOCK_REALTIME phc offset        25 s2 freq  +12383 delay    511
May 28 09:35:35 lon5g-sp-33 phc2sys[1029]: phc2sys[71486.272]: CLOCK_REALTIME phc offset        14 s2 freq  +12379 delay    504
May 28 09:35:35 lon5g-sp-33 phc2sys: [71486.272] CLOCK_REALTIME phc offset        14 s2 freq  +12379 delay    504
May 28 09:35:35 lon5g-sp-33 phc2sys[1029]: phc2sys[71486.397]: CLOCK_REALTIME phc offset       -18 s2 freq  +12352 delay    557
May 28 09:35:35 lon5g-sp-33 phc2sys: [71486.397] CLOCK_REALTIME phc offset       -18 s2 freq  +12352 delay    557
May 28 09:35:36 lon5g-sp-33 phc2sys[1029]: phc2sys[71486.522]: CLOCK_REALTIME phc offset        15 s2 freq  +12379 delay    512
May 28 09:35:36 lon5g-sp-33 phc2sys: [71486.522] CLOCK_REALTIME phc offset        15 s2 freq  +12379 delay    512
May 28 09:35:36 lon5g-sp-33 phc2sys[1029]: phc2sys[71486.648]: CLOCK_REALTIME phc offset       -17 s2 freq  +12352 delay    561
May 28 09:35:36 lon5g-sp-33 phc2sys: [71486.648] CLOCK_REALTIME phc offset       -17 s2 freq  +12352 delay    561
May 28 09:35:36 lon5g-sp-33 phc2sys[1029]: phc2sys[71486.773]: CLOCK_REALTIME phc offset       -12 s2 freq  +12352 delay    562
May 28 09:35:36 lon5g-sp-33 phc2sys: [71486.773] CLOCK_REALTIME phc offset       -12 s2 freq  +12352 delay    562
May 28 09:35:36 lon5g-sp-33 phc2sys[1029]: phc2sys[71486.898]: CLOCK_REALTIME phc offset        -8 s2 freq  +12352 delay    562
May 28 09:35:36 lon5g-sp-33 phc2sys: [71486.898] CLOCK_REALTIME phc offset        -8 s2 freq  +12352 delay    562
May 28 09:35:36 lon5g-sp-33 phc2sys[1029]: phc2sys[71487.023]: CLOCK_REALTIME phc offset        -4 s2 freq  +12354 delay    556
May 28 09:35:36 lon5g-sp-33 phc2sys: [71487.023] CLOCK_REALTIME phc offset        -4 s2 freq  +12354 delay    556
May 28 09:35:36 lon5g-sp-33 ptp4l[94065]: ptp4l[71487.055]: rms    1 max    2 freq  -6671 +/-   2 delay    13 +/-   1
May 28 09:35:36 lon5g-sp-33 ptp4l: [71487.055] rms    1 max    2 freq  -6671 +/-   2 delay    13 +/-   1
May 28 09:35:36 lon5g-sp-33 phc2sys[1029]: phc2sys[71487.149]: CLOCK_REALTIME phc offset        -5 s2 freq  +12351 delay    561
May 28 09:35:36 lon5g-sp-33 phc2sys: [71487.149] CLOCK_REALTIME phc offset        -5 s2 freq  +12351 delay    561
May 28 09:35:36 lon5g-sp-33 phc2sys[1029]: phc2sys[71487.274]: CLOCK_REALTIME phc offset        30 s2 freq  +12385 delay    524
May 28 09:35:36 lon5g-sp-33 phc2sys: [71487.274] CLOCK_REALTIME phc offset        30 s2 freq  +12385 delay    524
May 28 09:35:36 lon5g-sp-33 phc2sys[1029]: phc2sys[71487.399]: CLOCK_REALTIME phc offset        12 s2 freq  +12376 delay    562
May 28 09:35:36 lon5g-sp-33 phc2sys: [71487.399] CLOCK_REALTIME phc offset        12 s2 freq  +12376 delay    562
May 28 09:35:37 lon5g-sp-33 phc2sys[1029]: phc2sys[71487.524]: CLOCK_REALTIME phc offset        -5 s2 freq  +12362 delay    565
May 28 09:35:37 lon5g-sp-33 phc2sys: [71487.524] CLOCK_REALTIME phc offset        -5 s2 freq  +12362 delay    565
May 28 09:35:37 lon5g-sp-33 phc2sys[1029]: phc2sys[71487.650]: CLOCK_REALTIME phc offset        10 s2 freq  +12376 delay    557
May 28 09:35:37 lon5g-sp-33 phc2sys: [71487.650] CLOCK_REALTIME phc offset        10 s2 freq  +12376 delay    557
May 28 09:35:37 lon5g-sp-33 phc2sys[1029]: phc2sys[71487.775]: CLOCK_REALTIME phc offset        -2 s2 freq  +12367 delay    558
May 28 09:35:37 lon5g-sp-33 phc2sys: [71487.775] CLOCK_REALTIME phc offset        -2 s2 freq  +12367 delay    558
May 28 09:35:37 lon5g-sp-33 phc2sys[1029]: phc2sys[71487.920]: CLOCK_REALTIME phc offset        27 s2 freq  +12395 delay    518
May 28 09:35:37 lon5g-sp-33 phc2sys: [71487.920] CLOCK_REALTIME phc offset        27 s2 freq  +12395 delay    518
May 28 09:35:37 lon5g-sp-33 phc2sys[1029]: phc2sys[71488.046]: CLOCK_REALTIME phc offset        -1 s2 freq  +12375 delay    557
May 28 09:35:37 lon5g-sp-33 phc2sys: [71488.046] CLOCK_REALTIME phc offset        -1 s2 freq  +12375 delay    557
May 28 09:35:37 lon5g-sp-33 phc2sys[1029]: phc2sys[71488.171]: CLOCK_REALTIME phc offset        -9 s2 freq  +12367 delay    561
May 28 09:35:37 lon5g-sp-33 phc2sys: [71488.171] CLOCK_REALTIME phc offset        -9 s2 freq  +12367 delay    561
May 28 09:35:37 lon5g-sp-33 ptp4l[94065]: ptp4l[71488.193]: rms    3 max    5 freq  -6677 +/-   2 delay    14 +/-   1
May 28 09:35:37 lon5g-sp-33 ptp4l: [71488.193] rms    3 max    5 freq  -6677 +/-   2 delay    14 +/-   1
May 28 09:35:37 lon5g-sp-33 phc2sys[1029]: phc2sys[71488.296]: CLOCK_REALTIME phc offset        -3 s2 freq  +12370 delay    561
May 28 09:35:37 lon5g-sp-33 phc2sys: [71488.296] CLOCK_REALTIME phc offset        -3 s2 freq  +12370 delay    561
May 28 09:35:37 lon5g-sp-33 phc2sys[1029]: phc2sys[71488.421]: CLOCK_REALTIME phc offset        21 s2 freq  +12394 delay    501
May 28 09:35:37 lon5g-sp-33 phc2sys: [71488.421] CLOCK_REALTIME phc offset        21 s2 freq  +12394 delay    501
May 28 09:35:38 lon5g-sp-33 phc2sys[1029]: phc2sys[71488.547]: CLOCK_REALTIME phc offset         1 s2 freq  +12380 delay    558
May 28 09:35:38 lon5g-sp-33 phc2sys: [71488.547] CLOCK_REALTIME phc offset         1 s2 freq  +12380 delay    558
May 28 09:35:38 lon5g-sp-33 phc2sys[1029]: phc2sys[71488.672]: CLOCK_REALTIME phc offset         0 s2 freq  +12379 delay    558
May 28 09:35:38 lon5g-sp-33 phc2sys: [71488.672] CLOCK_REALTIME phc offset         0 s2 freq  +12379 delay    558
May 28 09:35:38 lon5g-sp-33 phc2sys[1029]: phc2sys[71488.797]: CLOCK_REALTIME phc offset       -11 s2 freq  +12368 delay    561
May 28 09:35:38 lon5g-sp-33 phc2sys: [71488.797] CLOCK_REALTIME phc offset       -11 s2 freq  +12368 delay    561
May 28 09:35:38 lon5g-sp-33 phc2sys[1029]: phc2sys[71488.922]: CLOCK_REALTIME phc offset        16 s2 freq  +12392 delay    522
May 28 09:35:38 lon5g-sp-33 phc2sys: [71488.922] CLOCK_REALTIME phc offset        16 s2 freq  +12392 delay    522
May 28 09:35:38 lon5g-sp-33 phc2sys[1029]: phc2sys[71489.048]: CLOCK_REALTIME phc offset       -13 s2 freq  +12368 delay    560
May 28 09:35:38 lon5g-sp-33 phc2sys: [71489.048] CLOCK_REALTIME phc offset       -13 s2 freq  +12368 delay    560
May 28 09:35:38 lon5g-sp-33 phc2sys[1029]: phc2sys[71489.173]: CLOCK_REALTIME phc offset       -10 s2 freq  +12367 delay    561
May 28 09:35:38 lon5g-sp-33 phc2sys: [71489.173] CLOCK_REALTIME phc offset       -10 s2 freq  +12367 delay    561
May 28 09:35:38 lon5g-sp-33 phc2sys[1029]: phc2sys[71489.298]: CLOCK_REALTIME phc offset       -14 s2 freq  +12360 delay    561
May 28 09:35:38 lon5g-sp-33 phc2sys: [71489.298] CLOCK_REALTIME phc offset       -14 s2 freq  +12360 delay    561
May 28 09:35:38 lon5g-sp-33 ptp4l[94065]: ptp4l[71489.312]: rms    2 max    4 freq  -6673 +/-   3 delay    14 +/-   1
May 28 09:35:38 lon5g-sp-33 ptp4l: [71489.312] rms    2 max    4 freq  -6673 +/-   3 delay    14 +/-   1
May 28 09:35:38 lon5g-sp-33 phc2sys[1029]: phc2sys[71489.423]: CLOCK_REALTIME phc offset        25 s2 freq  +12395 delay    521
May 28 09:35:38 lon5g-sp-33 phc2sys: [71489.423] CLOCK_REALTIME phc offset        25 s2 freq  +12395 delay    521
May 28 09:35:39 lon5g-sp-33 phc2sys[1029]: phc2sys[71489.549]: CLOCK_REALTIME phc offset         3 s2 freq  +12380 delay    559
May 28 09:35:39 lon5g-sp-33 phc2sys: [71489.549] CLOCK_REALTIME phc offset         3 s2 freq  +12380 delay    559
May 28 09:35:39 lon5g-sp-33 phc2sys[1029]: phc2sys[71489.674]: CLOCK_REALTIME phc offset        -5 s2 freq  +12373 delay    561
May 28 09:35:39 lon5g-sp-33 phc2sys: [71489.674] CLOCK_REALTIME phc offset        -5 s2 freq  +12373 delay    561
May 28 09:35:39 lon5g-sp-33 phc2sys[1029]: phc2sys[71489.799]: CLOCK_REALTIME phc offset       -18 s2 freq  +12358 delay    565
May 28 09:35:39 lon5g-sp-33 phc2sys: [71489.799] CLOCK_REALTIME phc offset       -18 s2 freq  +12358 delay    565
May 28 09:35:39 lon5g-sp-33 phc2sys[1029]: phc2sys[71489.924]: CLOCK_REALTIME phc offset       -16 s2 freq  +12355 delay    561
May 28 09:35:39 lon5g-sp-33 phc2sys: [71489.924] CLOCK_REALTIME phc offset       -16 s2 freq  +12355 delay    561
May 28 09:35:39 lon5g-sp-33 phc2sys[1029]: phc2sys[71490.050]: CLOCK_REALTIME phc offset        -9 s2 freq  +12357 delay    561
May 28 09:35:39 lon5g-sp-33 phc2sys: [71490.050] CLOCK_REALTIME phc offset        -9 s2 freq  +12357 delay    561
May 28 09:35:39 lon5g-sp-33 phc2sys[1029]: phc2sys[71490.175]: CLOCK_REALTIME phc offset       -11 s2 freq  +12353 delay    561
May 28 09:35:39 lon5g-sp-33 phc2sys: [71490.175] CLOCK_REALTIME phc offset       -11 s2 freq  +12353 delay    561
May 28 09:35:39 lon5g-sp-33 phc2sys[1029]: phc2sys[71490.340]: CLOCK_REALTIME phc offset        19 s2 freq  +12379 delay    519
May 28 09:35:39 lon5g-sp-33 phc2sys: [71490.340] CLOCK_REALTIME phc offset        19 s2 freq  +12379 delay    519
May 28 09:35:39 lon5g-sp-33 ptp4l[94065]: ptp4l[71490.429]: rms    1 max    3 freq  -6675 +/-   2 delay    14 +/-   1
May 28 09:35:39 lon5g-sp-33 ptp4l: [71490.429] rms    1 max    3 freq  -6675 +/-   2 delay    14 +/-   1
May 28 09:35:39 lon5g-sp-33 phc2sys[1029]: phc2sys[71490.466]: CLOCK_REALTIME phc offset         5 s2 freq  +12371 delay    566
May 28 09:35:39 lon5g-sp-33 phc2sys: [71490.466] CLOCK_REALTIME phc offset         5 s2 freq  +12371 delay    566
May 28 09:35:40 lon5g-sp-33 phc2sys[1029]: phc2sys[71490.611]: CLOCK_REALTIME phc offset         1 s2 freq  +12368 delay    562
May 28 09:35:40 lon5g-sp-33 phc2sys: [71490.611] CLOCK_REALTIME phc offset         1 s2 freq  +12368 delay    562
May 28 09:35:40 lon5g-sp-33 phc2sys[1029]: phc2sys[71490.736]: CLOCK_REALTIME phc offset        19 s2 freq  +12387 delay    518
May 28 09:35:40 lon5g-sp-33 phc2sys: [71490.736] CLOCK_REALTIME phc offset        19 s2 freq  +12387 delay    518
May 28 09:35:40 lon5g-sp-33 phc2sys[1029]: phc2sys[71490.862]: CLOCK_REALTIME phc offset        13 s2 freq  +12386 delay    517
May 28 09:35:40 lon5g-sp-33 phc2sys: [71490.862] CLOCK_REALTIME phc offset        13 s2 freq  +12386 delay    517
May 28 09:35:40 lon5g-sp-33 phc2sys[1029]: phc2sys[71490.987]: CLOCK_REALTIME phc offset        18 s2 freq  +12395 delay    521
May 28 09:35:40 lon5g-sp-33 phc2sys: [71490.987] CLOCK_REALTIME phc offset        18 s2 freq  +12395 delay    521
May 28 09:35:40 lon5g-sp-33 phc2sys[1029]: phc2sys[71491.112]: CLOCK_REALTIME phc offset        18 s2 freq  +12401 delay    519
May 28 09:35:40 lon5g-sp-33 phc2sys: [71491.112] CLOCK_REALTIME phc offset        18 s2 freq  +12401 delay    519
May 28 09:35:40 lon5g-sp-33 phc2sys[1029]: phc2sys[71491.237]: CLOCK_REALTIME phc offset        23 s2 freq  +12411 delay    510
May 28 09:35:40 lon5g-sp-33 phc2sys: [71491.237] CLOCK_REALTIME phc offset        23 s2 freq  +12411 delay    510
May 28 09:35:40 lon5g-sp-33 phc2sys[1029]: phc2sys[71491.363]: CLOCK_REALTIME phc offset         8 s2 freq  +12403 delay    517
May 28 09:35:40 lon5g-sp-33 phc2sys: [71491.363] CLOCK_REALTIME phc offset         8 s2 freq  +12403 delay    517
May 28 09:35:41 lon5g-sp-33 phc2sys[1029]: phc2sys[71491.508]: CLOCK_REALTIME phc offset       -32 s2 freq  +12365 delay    559
May 28 09:35:41 lon5g-sp-33 phc2sys: [71491.508] CLOCK_REALTIME phc offset       -32 s2 freq  +12365 delay    559

0 replies

jshacke · 2025-05-29T09:06:36Z

jshacke
May 29, 2025
Author

haplab@haplab:~/srsRAN_Project/configs$ sudo ptp4l -2 -i eno12429np3 -f default.cfg -m -H
ptp4l[84267.691]: selected /dev/ptp3 as PTP clock
ptp4l[84267.713]: port 1 (eno12429np3): INITIALIZING to LISTENING on INIT_COMPLETE
ptp4l[84267.713]: port 0 (/var/run/ptp4l): INITIALIZING to LISTENING on INIT_COMPLETE
ptp4l[84267.713]: port 0 (/var/run/ptp4lro): INITIALIZING to LISTENING on INIT_COMPLETE
ptp4l[84267.768]: port 1 (eno12429np3): new foreign master 000580.fffe.08659b-13
ptp4l[84268.033]: selected best master clock 000580.fffe.08659b
ptp4l[84268.033]: port 1 (eno12429np3): LISTENING to UNCALIBRATED on RS_SLAVE
ptp4l[84269.970]: port 1 (eno12429np3): minimum delay request interval 2^-4
ptp4l[84270.291]: port 1 (eno12429np3): UNCALIBRATED to SLAVE on MASTER_CLOCK_SELECTED
ptp4l[84271.064]: rms 6492264 max 12984647 freq -6593 +/- 376 delay 37 +/- 8
ptp4l[84272.189]: rms 219 max 475 freq -6520 +/- 170 delay 40 +/- 3
ptp4l[84273.314]: rms 56 max 93 freq -6272 +/- 88 delay 45 +/- 1
ptp4l[84274.439]: rms 78 max 119 freq -6168 +/- 107 delay 42 +/- 7
ptp4l[84275.564]: rms 58 max 155 freq -6179 +/- 94 delay 49 +/- 0
ptp4l[84276.689]: rms 29 max 74 freq -6175 +/- 47 delay 48 +/- 0
ptp4l[84277.814]: rms 9 max 34 freq -6192 +/- 14 delay 48 +/- 1
ptp4l[84278.939]: rms 66 max 163 freq -6243 +/- 103 delay 46 +/- 5
ptp4l[84280.064]: rms 74 max 166 freq -6185 +/- 119 delay 38 +/- 14
ptp4l[84281.189]: rms 76 max 136 freq -6183 +/- 126 delay 37 +/- 18
ptp4l[84282.314]: rms 48 max 151 freq -6201 +/- 79 delay 48 +/- 0
ptp4l[84283.439]: rms 48 max 141 freq -6208 +/- 80 delay 47 +/- 0
ptp4l[84284.564]: rms 48 max 136 freq -6202 +/- 79 delay 48 +/- 0
ptp4l[84285.688]: rms 62 max 168 freq -6211 +/- 104 delay 48 +/- 0
ptp4l[84286.813]: rms 67 max 130 freq -6180 +/- 108 delay 45 +/- 9

2 replies

VikrantDigiCat May 30, 2025

@jshacke Can you check your PTP gM config on the Falcon switch. Here is mine for reference.

VikrantDigiCat May 30, 2025

jshacke · 2025-06-02T14:17:34Z

jshacke
Jun 2, 2025
Author

Closing: hardware issue, was NIC related. Replaced with Intel 82599ES and PTP functions as expected

0 replies

LinuxPTP synchronisation drifts when starting gnb #1216

Uh oh!

jshacke May 20, 2025

Replies: 4 comments · 5 replies

Uh oh!

VikrantDigiCat May 28, 2025

Uh oh!

jshacke May 28, 2025 Author

Uh oh!

VikrantDigiCat May 28, 2025

Uh oh!

jshacke May 29, 2025 Author

Uh oh!

Uh oh!

VikrantDigiCat May 28, 2025

Uh oh!

jshacke May 29, 2025 Author

Uh oh!

VikrantDigiCat May 30, 2025

Uh oh!

VikrantDigiCat May 30, 2025

Uh oh!

jshacke Jun 2, 2025 Author

jshacke
May 20, 2025

Replies: 4 comments 5 replies

VikrantDigiCat
May 28, 2025

jshacke May 28, 2025
Author

jshacke May 29, 2025
Author

VikrantDigiCat
May 28, 2025

jshacke
May 29, 2025
Author

jshacke
Jun 2, 2025
Author