From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-x22b.google.com (mail-we0-x22b.google.com [IPv6:2a00:1450:400c:c03::22b]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id A4B6A21F1BB for ; Mon, 24 Feb 2014 08:47:33 -0800 (PST) Received: by mail-we0-f171.google.com with SMTP id u56so4929877wes.16 for ; Mon, 24 Feb 2014 08:47:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=rfICOxRG8Qtixnucl/O0FYC9eh63yzqjtVQYNAbtoI8=; b=jWdsk99ogI8cXMx08sK23fOJ7r1eH7Vl6a1fp7f9m1WJSDE5cWsVZCooXTkYQfCO6E aVg3JngUo3EonwrB1bU5VnNHiBMP86Orih0CrZvKzycyjm4uLDStZ84Y17fMLoVbsbg1 imm0Ck6KjccbD7VCojqFV3ChLeLxrxdPWAyeYLupCmTWcnerKkYeFnXI0kBCxL2DWLRA xw4/IV/DdJSC25znHAbLMDh+FEL9yp7tKH3FJnsgh2prOvJh72J2koS8vOW+paDqy1gT Om0UCNMHAaO5paQ6FubZcz93uGfPkhsjzRhFFlqSKustp2UAmyaRDU68od3w3Hc2ouLZ /vnw== MIME-Version: 1.0 X-Received: by 10.194.57.140 with SMTP id i12mr19430723wjq.20.1393260451508; Mon, 24 Feb 2014 08:47:31 -0800 (PST) Received: by 10.216.8.1 with HTTP; Mon, 24 Feb 2014 08:47:31 -0800 (PST) In-Reply-To: References: <4E5BC321-2054-4364-BECC-DF34E0D20380@gmail.com> Date: Mon, 24 Feb 2014 11:47:31 -0500 Message-ID: From: Dave Taht To: Aaron Wood Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: cerowrt-devel Subject: Re: [Cerowrt-devel] Equivocal results with using 3.10.28-14 X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 24 Feb 2014 16:47:34 -0000 On Mon, Feb 24, 2014 at 11:38 AM, Aaron Wood wrote: > Rich, > > One thing that helped considerably on my my DSL link (21000/1200), was > turning on the Link Layer Adaptation. With that, and efq_codel, I've bee= n > very happy with the (nearly non-existent) latency. Yeah, I lost a couple > percent off the top, but the behavior is better. Although I was starting > from a much better base given that Free.fr's DSL modems already using eit= her > fq_codel or RED (I'm not sure the specifics, but I think Dave Taht's gott= en > them from Free.fr in the past). Free deployed fq_codel on the revolution V6 box 1.5 years back. They found it necessary to fiddle with the target, and shared with me nearly all the details of their setup and their formula for target, which I have embedded here: http://snapon.lab.bufferbloat.net/~d/draft-taht-home-gateway-best-practices= -00.html despite testing a lot on your line we didn't do much better than they... > Dave, the 40ms target is the buffer latency target? or how often the dro= p > rates are recomputed? It is the starting point for the drop scheduler to start thinking about dropping some packets. > or how often the drop > rates are recomputed? That's a RED or PIE -thinking way of looking at the problem, recomputing a random number across a fixed interval. the drop rates in codel are computed on a decreasing interval based on a invsqrt control law that is much smoother than pie or red. > > -Aaron > --=20 Dave T=E4ht Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.= html