From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f47.google.com (mail-wg0-f47.google.com [74.125.82.47]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 7FC8E208AC5 for ; Wed, 9 May 2012 17:16:36 -0700 (PDT) Received: by wgbfa7 with SMTP id fa7so702711wgb.28 for ; Wed, 09 May 2012 17:16:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; bh=agMjbrvSvbQKQ7cjoMk5tf482S9fXaSYi/1VK6k76aM=; b=M51SKOW4Av9LzLGyajND4yP0qyJxMfMYTkZ6/oviPOGdjEZCQcHFfczpVjeTymRgAK 4yDwgSlZK8xHajvdi55wSR5yrEy5iLcy4kcID2BpRabPwBsik0HZ5N+yVoKmG9xpt8t7 RK03WtHEH6Jy2xht3snVhfsqfkJXqIRBcXaBDBRTwk76SPFIEfFF1blOi+5cRKDK2sW8 oc8ZsL+RPXu641k66TvwFKFi4kimgSugjJuO1GFaQKB+7YGs+kZntSsFvBOdoHHbc9Vj kKgaZw29Z+Hzkzq8k3Ps6+6e40ebaQ4gb67oKdRdry8qptURKMBz2BUTQzmaCIFe08CV DPew== Received: by 10.180.81.37 with SMTP id w5mr1573118wix.16.1336608994259; Wed, 09 May 2012 17:16:34 -0700 (PDT) Received: from [172.28.91.135] ([74.125.122.49]) by mx.google.com with ESMTPS id h8sm15107613wix.4.2012.05.09.17.16.32 (version=SSLv3 cipher=OTHER); Wed, 09 May 2012 17:16:33 -0700 (PDT) From: Eric Dumazet To: "Steinar H. Gunderson" In-Reply-To: <20120510000854.GB8131@uio.no> References: <4FA9FDC0.9010600@superduper.net> <44673AC5-4320-4C19-9788-87A63C47549D@cisco.com> <4FAAE5F0.2030404@freedesktop.org> <1336607919.12504.119.camel@edumazet-glaptop> <20120510000854.GB8131@uio.no> Content-Type: text/plain; charset="UTF-8" Date: Thu, 10 May 2012 02:16:31 +0200 Message-ID: <1336608991.12504.123.camel@edumazet-glaptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Cc: bloat@lists.bufferbloat.net Subject: Re: [Bloat] [Codel] The challenge X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 May 2012 00:16:36 -0000 On Thu, 2012-05-10 at 02:08 +0200, Steinar H. Gunderson wrote: > On Thu, May 10, 2012 at 01:58:39AM +0200, Eric Dumazet wrote: > > One solution is at the producer level (TCP stack of the sender in this > > case) to properly pace the transmits in MSS units given the RTT and > > cwnd, supposedly done with TCP Hybla. > > FWIW, I gave Hybla a quick test (echo hybla > /proc/sys/net/ipv4/tcp_congestion_control > and then start a VLC server; Linux 3.3.4 on both sides), and it doesn't pace > for me. It happily sends packets at what appears to be line speed, even to a > host ~100ms away on a much slower line. You should carefuly read http://hybla.deis.unibo.it/ Linux implementation Starting from kernel 2.6.13 Hybla has been included in the official Linux kernel. However, this implementation, based on the "module" Linux technology, does not include the last two Hybla components: Hoe's channel bandwidth estimate and packet spacing. Their addition is mandatory to fully benefit from Hybla performance improvement. To this end, it is enough to patch the official kernel with the MultiTCP package, downloadable from the downloads section.