From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from g6t0187.atlanta.hp.com (g6t0187.atlanta.hp.com [15.193.32.64]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "smtp.hp.com", Issuer "VeriSign Class 3 Secure Server CA - G3" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 79C8921F0AC for ; Fri, 31 Aug 2012 10:31:19 -0700 (PDT) Received: from g5t0012.atlanta.hp.com (g5t0012.atlanta.hp.com [15.192.0.49]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by g6t0187.atlanta.hp.com (Postfix) with ESMTPS id 25871283F7; Fri, 31 Aug 2012 17:31:18 +0000 (UTC) Received: from [16.103.148.51] (tardy.usa.hp.com [16.103.148.51]) by g5t0012.atlanta.hp.com (Postfix) with ESMTPSA id BC65A10002; Fri, 31 Aug 2012 17:31:17 +0000 (UTC) Message-ID: <5040F4E4.6000204@hp.com> Date: Fri, 31 Aug 2012 10:31:16 -0700 From: Rick Jones User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: Jim Gettys References: <1346396137.2586.301.camel@edumazet-glaptop> <5040DDE9.7030507@hp.com> <5040E8EE.2070900@freedesktop.org> <187CE1B3-6772-4E1C-A983-3AEC637C04FE@gmail.com> <5040F143.2010108@freedesktop.org> In-Reply-To: <5040F143.2010108@freedesktop.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: codel@lists.bufferbloat.net Subject: Re: [Codel] fq_codel : interval servo X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Aug 2012 17:31:19 -0000 On 08/31/2012 10:15 AM, Jim Gettys wrote: > What is more, consumer ethernet switches do do flow control, whether you > want them to or not. My understanding is that Ethernet flow control (what ever its 802.1mumble might be?) is negotiated when the link is brought-up, and that both sides must agree before it will be active. So, if you (the end station) do not want flow control, you can simply not accept it during link-up. Under Linux, the ethtool utility can be used to affect the configuration of "pause" (the name coming from the name of the frames used by flow control - "pause frames" if I recall correctly) rick