From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pz0-f43.google.com (mail-pz0-f43.google.com [209.85.210.43]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id E9FD721F0E0; Mon, 14 May 2012 11:35:58 -0700 (PDT) Received: by dajz8 with SMTP id z8so10217370daj.16 for ; Mon, 14 May 2012 11:35:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=0FrOCnX7z2WZh/x+BURR+RxiOc8y7C9YWuIWhznuUjw=; b=LAM7Bih5Q3vCQsE8xVY0NlMZWJKMnU0Zu3maBc4G42q+wdnDP+L/1n1YVA0t3mpJ7j EtnOn67JqK3fUChs+Q86+JuTSpL3mQQcGIZyPt/mNXTDRFYE41x57JuCEOhjRmeocogx q6MIoCFw04BFxu/VgWpm5kcmGiy0gGjfjS5lIPG38AxqwiNW+UhC9gQNzk565PuKLirO JleDWvrbVBp2Qhk82lDbLmKbjPpsaENGqCvLDQEiK+66AnjK08eYi8QIT2xGG5abWydK ubDSw1FPF97RijH5Zm6wh4zab0KB5S6ynNMT577ARemJLxR2GutlFNOyG4R8drKxKavr x9Rw== Received: by 10.68.193.233 with SMTP id hr9mr25152524pbc.99.1337020558499; Mon, 14 May 2012 11:35:58 -0700 (PDT) Received: from ?IPv6:2001:4f8:3:203::c001? ([2001:4f8:3:203::c001]) by mx.google.com with ESMTPS id kb12sm22987382pbb.15.2012.05.14.11.35.56 (version=SSLv3 cipher=OTHER); Mon, 14 May 2012 11:35:57 -0700 (PDT) Message-ID: <4FB1508B.9070300@gmail.com> Date: Mon, 14 May 2012 11:35:55 -0700 From: dave taht User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120410 Thunderbird/11.0.1 MIME-Version: 1.0 To: Juliusz Chroboczek References: <4FB129EC.90200@gmail.com> <7imx5a3b4t.fsf@lanthane.pps.jussieu.fr> <1337018621.8512.592.camel@edumazet-glaptop> <4FB14C6E.7030604@gmail.com> <7i8vguvcma.fsf@lanthane.pps.jussieu.fr> In-Reply-To: <7i8vguvcma.fsf@lanthane.pps.jussieu.fr> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Cc: codel@lists.bufferbloat.net, bloat@lists.bufferbloat.net Subject: Re: [Codel] [Bloat] better tc support for bittorrent/diffserv 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: Mon, 14 May 2012 18:35:59 -0000 On 05/14/2012 11:30 AM, Juliusz Chroboczek wrote: >> I think, but am not certain, jch is referring to the problem of >> negotiating ecn over uTP. > No, I was actually unaware that Linux allows one to set the ECN bits > from userspace. It's also possible to get them from userspace. > > OTOH, you're right that µTP doesn't currently support ECN. Not that it > matters much, ECN is useful for interactive connections (where it can > avoid a one-RTT delay due to a packet loss) but pretty useless for bulk > transfers[1]. My scenario is that AQM isn't just for routers anymore. > > On a related note, the µTP framing is pretty horrible IMHO, and LEDBAT > is better implemented within TCP. Unfortunately, this is not possible > under Windows (yeah, I got one of the µTorrent guys to contact Microsoft > on this subject). > > On a note related to the related note, Transmission already has the > ability to make use of a non-default congestion controller for TCP: > > http://www.pps.jussieu.fr/~jch/software/bittorrent/tcp-congestion-control.html TCP_LEDBAT has been in cerowrt for months. Haven't played with it much, was mostly comparing westwood and cubic. http://perso.telecom-paristech.fr/~valenti/pmwiki/pmwiki.php?n=Main.LEDBAT Also have the ability to exercise alternate algorithms in the latest netperf in svn (as well as classification). > -- Juliusz > > [1] Marek Malowidzki, Simulation-based Study of ECN Performance in RED > Networks, In Proc. SPECTS'03. 2003.