From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-33-ewr.dyndns.com (mxout-028-ewr.mailhop.org [216.146.33.28]) by lists.bufferbloat.net (Postfix) with ESMTP id ADB312E00B9 for ; Thu, 17 Mar 2011 04:28:23 -0700 (PDT) Received: from scan-32-ewr.mailhop.org (scan-32-ewr.local [10.0.141.238]) by mail-33-ewr.dyndns.com (Postfix) with ESMTP id D69656F8536 for ; Thu, 17 Mar 2011 11:28:22 +0000 (UTC) X-Spam-Score: 0.0 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 134.99.112.233 Received: from rohrpostix.cs.uni-duesseldorf.de (rohrpostix.cs.uni-duesseldorf.de [134.99.112.233]) by mail-33-ewr.dyndns.com (Postfix) with ESMTP id A952D6F73D2 for ; Thu, 17 Mar 2011 11:28:18 +0000 (UTC) Received: from wurmloch.cs.uni-duesseldorf.de ([134.99.112.34] helo=[192.168.2.103]) by rohrpostix.cs.uni-duesseldorf.de with esmtpsa (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.69) (envelope-from ) id 1Q0BNI-0006kw-Vw; Thu, 17 Mar 2011 12:28:16 +0100 Message-ID: <4D81F050.6060201@cs.uni-duesseldorf.de> Date: Thu, 17 Mar 2011 12:28:16 +0100 From: Florian Tschorsch Organization: =?UTF-8?B?SGVpbnJpY2gtSGVpbmUtVW5pdmVyc2l0w6R0IETDvHNzZWxkbw==?= =?UTF-8?B?cmY=?= User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.14) Gecko/20110223 Lightning/1.0b2 Thunderbird/3.1.8 MIME-Version: 1.0 To: bloat@lists.bufferbloat.net Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: [Bloat] Unleashing Tor, BitTorrent & Co.: How, to Relieve TCP Deficiencies in Overlays 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, 17 Mar 2011 11:28:24 -0000 Hi Everyone, I recently came across your project about bufferbloat. It seems that you are following similiar aims as we did in one of our contributions. We analyzed the effects and implications of TCP interferences in overlay networks cuased by saturated interface queues. Further we show that traffic shaping mechanisms alone are not enough and thus propose a methodology to overcome this issue. Abstract: In TCP-based overlay applications, the TCP connections of one peer typically share one physical Internet link. Using real-world experiments, we demonstrate that this can lead to undesirable interactions, causing significant throughput loss. We argue that such effects should be taken into account in the design of overlay networks, and identify readily deployable countermeasures. In a first step, we show that with existing operating system QoS functionality some relief is possible. Yet, this alone is not fully effective if peers communicate bidirectionally, due to piggybacked ACKs. We propose to separate bidirectionally used overlay links into two independent TCP connections, and demonstrate the effectiveness of this strategy. A more in-depth discussion, including experimental results etc., has been accepted as a paper to last year's IEEE LCN conference (Marks, Tschorsch, Scheuermann: "Unleashing Tor, BitTorrent & Co.: How to Relieve TCP Deficiencies in Overlays"). An extended version of this paper (even more results...) is available as a technical report here: http://www.cn.uni-duesseldorf.de/publications/library/Marks2010b.pdf If you have further questions, please do not hesitate to ask. Cheers, Florian. -- Florian Tschorsch Mobile and Decentralized Networks Heinrich-Heine-University Universitätsstr. 1, D-40225 Düsseldorf Building 25.12, Room 02.43 Phone +49 211 81 11635 Fax +49 211 81 11638 tschorsch@cs.uni-duesseldorf.de http://www.cn.uni-duesseldorf.de