From owner-freebsd-hackers Thu Sep 27 20:40:57 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from whizzo.transsys.com (whizzo.TransSys.COM [144.202.42.10]) by hub.freebsd.org (Postfix) with ESMTP id 8092237B401 for ; Thu, 27 Sep 2001 20:40:55 -0700 (PDT) Received: from whizzo.transsys.com (#6@localhost.transsys.com [127.0.0.1]) by whizzo.transsys.com (8.11.4/8.11.4) with ESMTP id f8S3esZ71606; Thu, 27 Sep 2001 23:40:54 -0400 (EDT) (envelope-from louie@whizzo.transsys.com) Message-Id: <200109280340.f8S3esZ71606@whizzo.transsys.com> X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Ronald G Minnich Cc: Andrew Gallatin , hackers@FreeBSD.ORG X-Image-URL: http://www.transsys.com/louie/images/louie-mail.jpg From: "Louis A. Mamakos" Subject: Re: TCP&IP cksum offload on FreeBSD 4.2 References: In-reply-to: Your message of "Thu, 27 Sep 2001 12:54:13 MDT." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 27 Sep 2001 23:40:54 -0400 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > On Thu, 27 Sep 2001, Andrew Gallatin wrote: > > > Geez. All I wanted to do was pat Jonathan on the back for coming up > > with what is apparently the most flexible and well though out > > mechanism out there. > > it's great work. I was mainly curious to see if anyone had measured this > kind of problem. > > Thanks The paper that someone mentioned earlier in this thread had some statistics on various classes of errors. In a nutshell, they put packet sniffers on 4 different networks, and collected traffic. For each back packet (where the checksum and ethernet CRC differed), they then looked for retransmissions of the same data, and tried to characterize the different failure modes they observed. It's very interesting reading. louie To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message