From owner-freebsd-net@FreeBSD.ORG Wed Jan 28 10:49:26 2009 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A3B78106564A for ; Wed, 28 Jan 2009 10:49:26 +0000 (UTC) (envelope-from per.hurtig@gmail.com) Received: from rv-out-0506.google.com (rv-out-0506.google.com [209.85.198.231]) by mx1.freebsd.org (Postfix) with ESMTP id 7A5738FC12 for ; Wed, 28 Jan 2009 10:49:26 +0000 (UTC) (envelope-from per.hurtig@gmail.com) Received: by rv-out-0506.google.com with SMTP id b25so7004555rvf.43 for ; Wed, 28 Jan 2009 02:49:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:date :x-google-sender-auth:message-id:subject:from:to:content-type :content-transfer-encoding; bh=zvNx2ZT/0abPb1cLBrueRUKWOkQV3s6xKGgXNC0SFBE=; b=jBWc5LZiqQXmbvG78SP/9BBPZOds+Z13NRKhAeROgljTiHjOMJhu1NnH3mphJVIpvr ChLBzw36TbDNfw+zAwxLuS+LiA4GuUopwR03tCs47d8VCEDU9uQNypOU5cVEmARUMinm oxCndEwsydaM88Asp+Vo5BE00Q1nXxb/ygPSo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:date:x-google-sender-auth:message-id:subject :from:to:content-type:content-transfer-encoding; b=xj+GCGWfRxfctbTxxvsLtPoH0wi14x2dRXO4ElgXyLuO2eD4mqCp3hQHsM8iSjrog7 WePSZ9WeT9lXue81fQrf7dRJRjJ7Lnd3zXp45Zw6/UcL3cLBRrCl5MRk0LeRODh2SV6i 1jn5raXv8+YlLpLPFldAj4gRIWUX5qrw6NyZE= MIME-Version: 1.0 Sender: per.hurtig@gmail.com Received: by 10.115.47.1 with SMTP id z1mr2736276waj.133.1233139766065; Wed, 28 Jan 2009 02:49:26 -0800 (PST) Date: Wed, 28 Jan 2009 11:49:26 +0100 X-Google-Sender-Auth: 7d708aaa9ca9c90a Message-ID: From: "Per Hurtig (work)" To: freebsd-net@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: TCP gets special treatment? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Jan 2009 10:49:26 -0000 Hi, How differently are TCP packets treated compared to e.g. SCTP packets, while traversing the FreeBSD network stack (up to and including the IP-layer when using ipfw)?. I do not assume that the firewall (ipfw) is explicitly configured to check for established sessions or any TCP specifics. Are there a lot of TCP-specific optimizations conducted by lower layers anyways (besides possible checksum offloading)? BR, Per