Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 28 Sep 2001 09:52:18 -0400 (EDT)
From:      Andrew Gallatin <gallatin@cs.duke.edu>
To:        tlambert2@mindspring.com
Cc:        Jonathan Lemon <jlemon@flugsvamp.com>, the_srinivas@hotmail.com, hackers@freebsd.org
Subject:   Re: TCP&IP cksum offload on FreeBSD 4.2
Message-ID:  <15284.32914.874966.260722@grasshopper.cs.duke.edu>
In-Reply-To: <3BB42E50.B32F5E95@mindspring.com>
References:  <200109270157.f8R1vZ546863@prism.flugsvamp.com> <3BB42E50.B32F5E95@mindspring.com>

next in thread | previous in thread | raw e-mail | index | archive | help

Terry Lambert writes:
 > Jonathan Lemon wrote:
 > > >I'm trying to use the TCP&IP checksum offload capability of the Netgear
 > > >GA620 NIC from a SMP FreeBSD 4.2R system running on a typical PIII SBC.
<..>
 > 
 > He didn't say his packet size, either.
 > 
 > To the original poster: if you are sending jumbograms, the
 > buffer size on these cards is limited, so the entire packet
 > can't be in the card buffer at the same time, which means
 > that you can not offload the send checksum for jumbograms,
 > only for regular sized packets.

This is an Alteon Tigon-2 (ti driver) based card with 512K of sram on board.
It has plenty of space for offloading transmit checksums on jumbo frames.

Perhaps you're thinking of the DP83820/DP83821 (nge driver), which
cannot compute the checksum on an outgoing frame unless it fits in the
8K tx fifo.  I think NetGear sells a card with a similar name (GA622T)
based around this chip.

Drew



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?15284.32914.874966.260722>