From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ia0-x229.google.com (mail-ia0-x229.google.com [IPv6:2607:f8b0:4001:c02::229]) (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 D71AF202102 for ; Wed, 20 Mar 2013 08:55:08 -0700 (PDT) Received: by mail-ia0-f169.google.com with SMTP id j5so1566018iaf.0 for ; Wed, 20 Mar 2013 08:55:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:cc:content-type:content-transfer-encoding; bh=XofvBbWdw5oGi5p3NXT8pVxm4pW2HsPtv4nXZxwlcDQ=; b=tkL2aiWoQ3fJp6xDQoUF4n9f7ACxzdRn2SRTC6gqTV4HK1KXk6UE4hCccrwE7InEOw rOmP66GlM8cDgiC2ZpU5pHvzv19ETAINYuqUtqoHr35RsNXyozHN5d2U8YsCLLEaEAZR vpUFet57gCMke3Ph7FwLwAwDfQU6F+pi6X3n6YyJ74na93quEaOfd90LD3VGXxmm40xe b2JBrMNVssAKwLQ8T5Q4ZQl6dSVN18Rgd2B4M2uPhNv8TuNLEjHw4Nunc1z4OZz/CWH9 VQHqHt55gRAvPy75ZXGJVKURkbCeWqSs9DVKlzYye7ktdS2TTR6QdQzsAr9/DGa8OSqp kRAg== MIME-Version: 1.0 X-Received: by 10.50.36.169 with SMTP id r9mr1898648igj.96.1363794908008; Wed, 20 Mar 2013 08:55:08 -0700 (PDT) Received: by 10.64.132.71 with HTTP; Wed, 20 Mar 2013 08:55:07 -0700 (PDT) In-Reply-To: References: Date: Wed, 20 Mar 2013 11:55:07 -0400 Message-ID: From: Dave Taht To: Steffan Norberhuis Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: bloat@lists.bufferbloat.net Subject: Re: [Bloat] Solving bufferbloat with TCP using packet delay 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: Wed, 20 Mar 2013 15:55:09 -0000 On Wed, Mar 20, 2013 at 11:36 AM, Steffan Norberhuis wrote: > Hello Everyone, > > For a project for the Delft Technical University myself and 3 students ar= e > writing a review paper on the buffer bloat problem and its possible > solutions. I also subscribed to this mailinglist and see alot of proposed > solutions to be AQM. > > But hardly any talk about solving buffer bloat by using a TCP variant tha= t > that uses packet delay as a way to determine the send rate. We did not co= me > across any papers that argue that these TCP variants are not a good > solution. We went to several professors with the question if TCP using > packet delay was not a good solution. But we did not get a concise answer= . > In our view AQM needs alot of new hardware to be implemented and a TCP > variant would perhaps be easier to implement and is also able to solve > bufferbloat. LPCC has been pursued for a decade. the new AQM stuff outperforms it in nearly every respect. I'd put together what I'd hoped to be a foundational paper on it, in conjunction with some LEDBAT researchers. I couldn't get it published in full, full version is here: www.telecom-paristech.fr/~drossi/paper/rossi13tma-b.pdf I have not had a chance to work on the successor paper, running the same sorts of tests, using sfqred, or fq_codel. I have tons of data, just no time to process it and structure the experiments repeatably. The issue has also been discussed on this list and others, for ages. > > So I have a few questions I would like to ask you: > - Is TCP using packet delay considered as part of the solution for > bufferbloat? I think paced TCP shows more promise than any of the delay based TCPs, at least at present, on the edge, for things like DASH traffic. There are other possibilities being discussed in the rmcat ietf group. > - What are the problems of TCP delay variants that keep it from solving > bufferbloat? > > - What are the drawbacks of the TCP delay variants that would favor AQM o= ver > TCP? Nothing competes with packet loss/ECN marked based TCP effectively that we know of. A few, come fairly close. > - What are the advantages of TCP delay varaints that would favor TCP over > AQM? You, know, at this point, my answer is - Install Linux, get the RRUL test, enable every known variant of TCP, and try them with and without the AQMs that have been developed and now available in linux, with whatever variety of traffic you like, and get back to us with the results. It'll only take a day or so, to try it out. See the iccrg details for how to get started, or the stanford and MIT presos. http://netseminar.stanford.edu http://www.ietf.org/proceedings/86/slides/slides-86-iccrg-0.pdf > Best regards, > > Steffan Norberhuis > > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > --=20 Dave T=E4ht Fixing bufferbloat with cerowrt: http://www.teklibre.com/cerowrt/subscribe.= html