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From: "Lu, Wenzhuo" <wenzhuo.lu@intel.com>
To: Asim Jamshed <asim.jamshed@gmail.com>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] Fwd: dpdk ixgbe PMD lro limits
Date: Tue, 28 Jun 2016 08:42:33 +0000	[thread overview]
Message-ID: <6A0DE07E22DDAD4C9103DF62FEBC09090348B7E1@shsmsx102.ccr.corp.intel.com> (raw)
In-Reply-To: <CANwh_8aS-FLx7zNkfEy7QiS-CP+NFHXPXPamx4yrQgiibo9BuA@mail.gmail.com>

Hi Asim,


> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Asim Jamshed
> Sent: Tuesday, June 28, 2016 2:41 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] Fwd: dpdk ixgbe PMD lro limits
> 
> Hi,
> 
> Apologies in advance if this question has been asked in the past.
> 
> I have been performing mTCP-related tests on dpdk-16.04 with ixgbe PMD. I am
> using 82599ES 10-Gigabit adapters for my experiments. I have a few queries
> regarding LRO.
> 
> 1) What is the theoretical maximum size of the Ethernet frame I can get from
> the driver once LRO is enabled? In my experiments, I was seeing packet size as
> high as 16KB. Can it be as high as ~2^16 bytes (iph->tot_len)?
I'm not sure about if I understand your question correctly. Assume you're talking about the TCP segment after LRO. So, it's said there are no limitations on the maximum packet length.

> 
> 2) Since the NIC is reassembling payloads (of one flow) into a single packet,
> what does the Ethernet controller do with the tcp checksum field in the TCP
> header? I am observing that each LRO packet has checksum value as zero? Is
> that normal? I could not find any relevant documentation on the Web.
That's expected. 
You can search 82599 datasheet. I think that's what you're looking for.

> 
> Thanks in advance,
> --Asim

  reply	other threads:[~2016-06-28  8:42 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CANwh_8ZXFZhs3iBDJFq7ebPTXkWkMLJDgLcw4iMeVgnzW5+AoA@mail.gmail.com>
2016-06-28  6:41 ` Asim Jamshed
2016-06-28  8:42   ` Lu, Wenzhuo [this message]
2016-06-28  9:23     ` Asim Jamshed
2016-06-29  0:29       ` Lu, Wenzhuo

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