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ASadi1
Beginner
1,967 Views

I219V High Propagation Delay

Hi,

 

I have an https://www.intel.com/content/dam/support/us/en/documents/boardsandkits/NUC7i3BN_TechProdSpec.pdf Intel NUC7i3BNH with the I219V ethernet controller which is 802.1AS compliant according to its https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/ethernet-connection-i219-dat... datasheet.

I am trying to use it with ptp4l and a gPTP profile but I get really high propagation delays in the range of 7μs when connected directly to an I210 device or Extreme x440-48t switch. This is very high for hardware timestamping. For reference, the I210 has a propagation delay of around 20ns when connected to the switch or another I210. The gPTP profile needs a propagation delay below 800ns to be considered AS capable.

 

I tried updating the e1000e drivers to version 3.4.1.1-NAPI but results were the same.

I am using Ubuntu 18.04.1 LTS and 4.13.0-45-generic kernel.

Why is the propagation delay so high and what can I do to fix it? Is the I219V actually 802.1AS compliant?

Thanx,

Andre.

0 Kudos
18 Replies
idata
Community Manager
496 Views

Hi Andre,

 

 

Thank you for posting in Wired Ethernet Community.

 

 

Please share the output of your Ethtool -i.

 

 

Regards,

 

 

Vince T.

 

Intel Customer Support

 

Agent under contract to Intel
ASadi1
Beginner
496 Views

Hi Vince,

Thank you for the response. I just updated my kernel to 4.18.1-041801-generic so some info is a little different from the original post, such as the driver version.

Ethtool -i:

driver: e1000e

version: 3.2.6-k

firmware-version: 0.1-4

expansion-rom-version:

bus-info: 0000:00:1f.6

supports-statistics: yes

supports-test: yes

supports-eeprom-access: yes

supports-register-dump: yes

supports-priv-flags: no

Thank you,

Andre.

idata
Community Manager
496 Views

Hi Andre,

 

 

Thanks for providing the information, let me further check this issue and update this thread as soon as possible.

 

 

Regards,

 

 

Vince T.

 

Intel Customer Support

 

Agent under contract to Intel
ASadi1
Beginner
496 Views

Hi Vince,

Thank you for looking into it. Please let me know if I can provide any further information.

Andre.

idata
Community Manager
496 Views

Hi Andre,

 

 

Please share detail steps on how you're testing the propagation delay. Also, have you tried it on different operating system?

 

 

 

Regards,

 

 

Vince T.

 

Intel Customer Support

 

Agent under contract to Intel
ASadi1
Beginner
496 Views

Hi Vince,

I have not used any operating systems other than Ubuntu.

I have used Ubuntu 16.04 and 18.04.

Specifc kernels: 4.13.0-45-generic, 4.15.0-29-generic and 4.18.1-041801-generic

The I210 works fine on all the above.

Running the ptp4l (Linux PTP) module gives the propagation time between 2 devices. I am using the peer-delay mechanism as explained in the image below although E2E delay gives similar values.

Command used: sudo ptp4l -i eno1 -f gPTP.cfg -m

Short gPTP.cfg profile:

[global]

gmCapable 1

priority1 248

priority2 248

logAnnounceInterval 0

logSyncInterval -3

syncReceiptTimeout 3

neighborPropDelayThresh 800

min_neighbor_prop_delay -20000000

assume_two_step 1

path_trace_enabled 1

follow_up_info 1

transportSpecific 0x1

ptp_dst_mac 01:80:C2:00:00:0E

network_transport L2

delay_mechanism P2P

The propagation delay can also be observed from the Extreme x440-48t switch side.

X440-48t.14 # show network-clock gptp port 31

Physical port number : 31

gPTP port status : Enabled

Clock Identity : 00:04:96:ff:fe:9a:91:d2

gPTP Port Number : 31

IEEE 802.1AS Capable : No

Port Role : 3 (Disabled)

Announce Initial Interval : 0 (1.000 secs)

Announce Current Interval : 0 (1.000 secs)

Announce Receipt Timeout : 3

Sync Initial Interval : -3 (0.125 secs)

Sync Current Interval : -3 (0.125 secs)

Sync Receipt Timeout : 3

Sync Receipt Timeout Interval : N/A

Measuring Propagation Delay : Yes

Propagation Delay : 7287 ns

Propagation Delay Threshold : 800 ns (auto)

Propagation Delay Asymmetry : 0

Peer Delay Initial Interval : 0 (1.000 secs)

Peer Delay Current Interval : 0 (1.000 secs)

Peer Delay Allowed Lost Responses : 3

Neighbor Rate Ratio : 0.999978

PTP Version : 2

You can also see this thread https://sourceforge.net/p/linuxptp/mailman/message/36386718/ https://sourceforge.net/p/linuxptp/mailman/message/36386718/ for a discussion about the I219V propagation time from the ptp4l side.

Regards,

Andre

idata
Community Manager
496 Views

Hi Andre,

 

 

Thank you for providing the information. We'll check further and update this thread as soon as possible.

 

 

Regards,

 

 

Vince T.

 

Intel Customer Support
ASadi1
Beginner
496 Views

Hi Vince,

Thank you for your time. Any update yet?

Thank you,

Andre.

idata
Community Manager
496 Views

Hi Andre,

 

 

We'd like to apologize for the delay, this issue is still being investigated.

 

 

Regards,

 

 

Vince T.

 

Intel Customer Support
idata
Community Manager
496 Views

Hi Andre,

 

 

Please try the driver version - 3.4.2.1. You may download the file from this https://sourceforge.net/projects/e1000/files/e1000e%20stable/3.4.2.1/ link.

 

 

Regards,

 

 

Vince T.

 

Intel Customer Support
ASadi1
Beginner
496 Views

Hi Vince,

Driver installed and the path delay is still the same.

ethtool -i:

driver: e1000e

version: 3.4.2.1-NAPI

firmware-version: 0.8-4

expansion-rom-version:

bus-info: 0000:00:1f.6

supports-statistics: yes

supports-test: yes

supports-eeprom-access: yes

supports-register-dump: yes

supports-priv-flags: no

idata
Community Manager
496 Views

Hi Andre,

 

 

After further investigation, the I210-T1 would be better for your usage. The IEEE 1588 was not a design consideration for the NUC with I219-V and there's no configuration available to alter the propagation delay.

 

 

Best regards,

 

 

Vince T.

 

Intel Customer Support
idata
Community Manager
496 Views

Hi Andre,

 

 

Please let us know if you have further clarification regarding your query. Thanks.

 

 

Best Regards,

 

 

Vince T.

 

Intel Customer Support
ASadi1
Beginner
496 Views

Hi Vince,

Thank you for the feedback.

 

I would like some clarification on why the NUC and I219-V specifications specifically state that they are 1588 compliant if it was not a design consideration? The main reason we purchased the NUCs is for their stated timestamping capabilities.

Regards,

Andre.

idata
Community Manager
496 Views

Hi Andre,

 

 

Let me check this internally and update the thread as soon as possible.

 

 

Best Regards,

 

 

Vince T.

 

Intel Customer Support
VincentT_Intel
Moderator
496 Views

Hi Andre,

 

How are you?

 

Please be informed we're still looking into your query and will post update soon.

 

Best Regards,

 

Vince

Intel Customer Support

Under Contract to Intel Corporation

VincentT_Intel
Moderator
496 Views

Hi Andre,

 

Even though the I219-V has higher propagation delay compared with I210, it is still 1588 compliant. The I210 has a different design implementation compared to I219 that produces better propagation delay. We apologized for the inconvenience this issue had caused you.

 

 

Best Regards,

 

Vince

Intel Customer Support

Under Contract to Intel Corporation

VincentT_Intel
Moderator
496 Views

Hi Andre,

 

Please let us know if there's other assistance needed.

 

 

Best Regards,

 

Vince

Intel Customer Support

Under Contract to Intel Corporation

 

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