From owner-freebsd-net@FreeBSD.ORG Mon Feb 1 07:28:11 2010 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 4DB6F106566C for ; Mon, 1 Feb 2010 07:28:11 +0000 (UTC) (envelope-from lstewart@freebsd.org) Received: from lauren.room52.net (lauren.room52.net [210.50.193.198]) by mx1.freebsd.org (Postfix) with ESMTP id 1194F8FC16 for ; Mon, 1 Feb 2010 07:28:10 +0000 (UTC) Received: from lstewart.caia.swin.edu.au (lstewart.caia.swin.edu.au [136.186.229.95]) by lauren.room52.net (Postfix) with ESMTPSA id E07217E824; Mon, 1 Feb 2010 18:28:08 +1100 (EST) Message-ID: <4B668285.1090605@freebsd.org> Date: Mon, 01 Feb 2010 18:28:05 +1100 From: Lawrence Stewart User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.1.5) Gecko/20100105 Thunderbird/3.0 MIME-Version: 1.0 To: Jerry Toung References: <86068e731001311449m605005cft7ebc6f8b984d6d96@mail.gmail.com> In-Reply-To: <86068e731001311449m605005cft7ebc6f8b984d6d96@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-net@freebsd.org Subject: Re: TCP westwood 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: Mon, 01 Feb 2010 07:28:11 -0000 Hi Jerry, On 02/01/10 09:49, Jerry Toung wrote: > Hello list, > my employer is asking me to implement westwood, this is most likely happen > on 8.0. > > before I start, I'd like to know for what reason it hasn't been done in the > main tree? > is it that no one has had time, or it only work in a lab environment? may be > too many changes in the stack > and it's not trivial? etc... IMHO, lack of a really compelling reason is a good start. Changing the TCP stack is fiddly and error prone work. > Does any one out there has patch they can share? I haven't come across a BSD licenced implementation in my travels, although FreeBSD already does a few different types of bandwidth estimation and limiting (which, in their current form at least, I'm personally not a fan of). > would the project be interested in a patch if I do this? I'm interested in and actively working on this area in FreeBSD. I already have a patch available that adds modular congestion control support to FreeBSD's TCP stack which would be a good starting point for you. I would also be supportive of importing a Westwood congestion control module into FreeBSD after you complete it. Have a look at the project branches here: http://svn.freebsd.org/base/projects/tcp_cc_{7.x,8.x,head} Happy to discuss further when you're ready. Cheers, Lawrence