Packet Timestamp Sampling Latency information not available for 82574L chip

[Skond11]

Hello Community,

I am working on supporting gPTP software for One of the Intel 82574L.

But i could not find the Packet Timestamp Sampling Latency for this 82574L chip in the Datasheet "https://www.intel.com/content/dam/doc/datasheet/82574l-gbe-controller-datasheet.pdf".

But I found the similar information for Intel I210 in below section in "https://www.intel.com/content/www/us/en/embedded/products/networking/i210-ethernet-controller-datasheet.html".

7.8.3.1 Capture Timestamp Mechanism (Table 7-63. Packet Timestamp Sampling Latency at 100 Mb/s (Arithmetic Mean and Exponential Smoothing)

Because of this unavailability of this latency information, we could not able to get the accuracy.

Could you please provide us this information.

[AlfredoS_Intel]

Hi Skond11,

Thank you for posting on Intel® Ethernet Communities page.

Please allow us some time to check on this. We will get back to you no later than 3 to 5 business days from now.

Best Regards,

Alfred S

Intel® Customer Support

A Contingent Worker at Intel 

[AlfredoS_Intel]

Hi Skond11,

Thanks for waiting for our update.

As much as we would like to have that measurement available for you, we really never measured anything in the same intensity as with the I210.

Here is what you can do:

1. You can do some measurements with two I210 connected to see the software behavior.

2. Then try to measure two 82574s to have an estimate of the PHY delays and then you can fine-tune it if you are using an I210 with an 82574.

We also noticed that you might have posted the same question and was responded to, on a github page, https://github.com/AVnu/gptp/issues/30#issuecomment-571453140.

Please confirm if you are the same person who posted on the forum above.

Please feel free to reply if you have any further questions.

Best Regards,

Alfred S

Intel® Customer Support

A Contingent Worker at Intel 

[Skond11]

Thank you Very Much Alfred S.

Yes, I have only the posted the question in https://github.com/AVnu/gptp/issues/30#issuecomment-571453140.

Thanks for these below steps

Here is what you can do:

1. You can do some measurements with two I210 connected to see the software behavior.

2. Then try to measure two 82574s to have an estimate of the PHY delays and then you can fine-tune it if you are using an I210 with an 82574.

Would it be possible to elaborate on these steps with some more information. This would really help us to measure the phy delays.

Thanks and regards

Santha Raju Kondeti.

[Crisselle_Intel]

Hi Skond11,

Thank you for the reply.

We will further check for additional information we can provide that would help you on your request. We will get back to you within 1-3 business days.

Hoping for your patience.

Best Regards,

Crisselle C

Intel® Customer Support

A Contingent Worker at Intel 

[AlfredoS_Intel]

Hi Skond11,

Thank you for patiently waiting.

It is difficult to do these types of measurements accurately.

May we know if there is a business reason why you need to use the 82574 rather than using the I210 that has testing and that has driver support for Precision Time Protocol?

Best Regards,

Alfred S

Intel® Customer Support

A Contingent Worker at Intel 

[AlfredoS_Intel]

Hi Skond11,

Please let us know if you need more time to provide the information that we are asking.

Best Regards,

Alfred S

Intel® Customer Support

A Contingent Worker at Intel 

[AlfredoS_Intel]

Hi Skond11,

I am just sending another follow up if you still have questions or clarifications. 

Since we have not heard back from you, we regretfully need to close this inquiry now. 

If you need further assistance, please post a new question. 

Best regards,

Alfred S.

Intel Customer Support

A Contingent Worker at Intel