topic Re: Maximum Size of Jumbo Frame in Layerscape

Maximum Size of Jumbo Frame

raratex — Thu, 17 Aug 2017 10:30:39 GMT

Hello NXP Community,

I have few questions regarding maximum size of Jumbo Frame by QorIQ/Layerscape ARMv8 platform.

There is a maximum size of L2 packet (MAXFRM) set to 9600. And there is also configuration point:

If I understand the hw implementation of eMAC correctly, Tx-Buffer is 10kB and Rx-Buffer is 2kB.

My questions:

1. how does match size of max l2 message (MAXFRM=9600) with rx-buffer?

2. can I change the size of MAXFRM to 15000, 20000, 50000, ...? and if yes, how?

3. optimization for jumbo frames cannot be done for LS1043, but why?

Thank you!

Best Regards,

Radek

Re: Maximum Size of Jumbo Frame

Pavel — Fri, 18 Aug 2017 03:07:22 GMT

What version of NXP SDK is used?

What processor is used on your board?

Have a great day,
Pavel Chubakov

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

Re: Maximum Size of Jumbo Frame

raratex — Fri, 18 Aug 2017 15:52:03 GMT

We are developing 3 different variants of hardware, using LS1043A, LS1046A, LS1088A (see Tags).

Actually, we are using SDK v0.4.

Re: Maximum Size of Jumbo Frame

Pavel — Mon, 21 Aug 2017 03:50:32 GMT

Usually maximum length of Jumbo frame is 9000 bytes:

https://en.wikipedia.org/wiki/Jumbo_frame

The LS10xx DPAA supports MAXFR value up to 32,736 bytes. For example see the Section 6.4.3.1.4 of the LS1046a DPAARM:

https://www.nxp.com/webapp/Download?colCode=LS1046ADPAARM&Parent_nodeId=1454450484961711127630&Parent_pageType=product&Parent_nodeId=1454450484961711127630&Parent_pageType=product

Have a great day,
Pavel Chubakov