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From: Asim Jamshed <asim.jamshed@gmail.com>
To: dev@dpdk.org
Subject: [dpdk-dev] Fwd: dpdk ixgbe PMD lro limits
Date: Tue, 28 Jun 2016 15:41:03 +0900	[thread overview]
Message-ID: <CANwh_8aS-FLx7zNkfEy7QiS-CP+NFHXPXPamx4yrQgiibo9BuA@mail.gmail.com> (raw)
In-Reply-To: <CANwh_8ZXFZhs3iBDJFq7ebPTXkWkMLJDgLcw4iMeVgnzW5+AoA@mail.gmail.com>

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)?

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.

Thanks in advance,
--Asim

       reply	other threads:[~2016-06-28  6:41 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 [this message]
2016-06-28  8:42   ` Lu, Wenzhuo
2016-06-28  9:23     ` Asim Jamshed
2016-06-29  0:29       ` Lu, Wenzhuo

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