From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-xd31.google.com (mail-io1-xd31.google.com [IPv6:2607:f8b0:4864:20::d31]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id C81B23B29E for ; Sat, 12 Dec 2020 13:11:57 -0500 (EST) Received: by mail-io1-xd31.google.com with SMTP id n14so12831104iom.10 for ; Sat, 12 Dec 2020 10:11:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:content-transfer-encoding:mime-version:subject:message-id:date :to; bh=B4I1xPkvRrzGxJEYAnF0vvwhEcZEQ3pbECIEsVpA0eA=; b=gPJQ/48Wgb4ll+GAsM08BRYfpOnTvuY4U1/i4YXwMGTQyK5pfsX+0ZVF7FmbRL0iMj 4tw6n3cVzCigyuoi6+uN7ldt1/73h6nbF4hkTk+487P6ZrGD/IqOTBrStsTZ/QTKnzSt OMNC2WTEavS37xcPBOKCajWRvofqmO85vkum3I/ixYOzpsaTUdfEOoPgyK1ewPjzWMLO PKbwQ4HkVw3QI8TCheF66FeGM66RObVHrgCppFcbB4VNC1p7sbJPpkeQnczo9kY4Dsgf 0mwWC5zB2WUNC24JQWUdXYCw0OCQHOjke/Rwiv9A8SU+e04jWtAtawPn7lTM8LkbdP85 tfDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:content-transfer-encoding:mime-version :subject:message-id:date:to; bh=B4I1xPkvRrzGxJEYAnF0vvwhEcZEQ3pbECIEsVpA0eA=; b=Hslz13tFgp5k/czA3p5q3tydquATWFaJve2X3z97gYK6MZFc1o+7j7xypchRvyuX2P 1+XsGPA7/9pytr8k4BZ6mV+yXWErqA6vWoWdtW0L1q+OTMi5e2b2izs7vBdVgaG7lroj VQvNEzNVFWjh4mv1JOsjEZ9o0C+xGpL3B+zaA7V80fiGYdBpVM+jQWyfVr5mke6ESOnr fDdR2y+y3r/kumlQxDenPf99GqXACZXzozLPigM2mdgdZVD8Za4Yrz6yqWK5jWNmOVI3 f6UeoSwp3UafOG+bWGxI6Dynlp4cN/Y8vc/T5sSQJ4b4ys/owIauSiOjhcUfP1iwKiqb dDBA== X-Gm-Message-State: AOAM533magi9kIlQ0kimDbBh/i1JP5mursMfuurBLJOSw87/76+H7doR y4NmTq7MlpDP1XPMM0sJ38MLgnpmv62EMg== X-Google-Smtp-Source: ABdhPJwwxlD3CDF5r2nOA9p94bFNggVOTNKdAzaMXIWWpcZDEZ+YzU7UvEPAUBU+P9J1EOOmS8wCQQ== X-Received: by 2002:a5d:9396:: with SMTP id c22mr22417678iol.12.1607796717000; Sat, 12 Dec 2020 10:11:57 -0800 (PST) Received: from ?IPv6:2001:470:8c46:0:e9f3:413c:6b00:c7d? ([2001:470:8c46:0:e9f3:413c:6b00:c7d]) by smtp.gmail.com with ESMTPSA id o195sm7849780ila.38.2020.12.12.10.11.56 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sat, 12 Dec 2020 10:11:56 -0800 (PST) From: Rich Brown Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.4\)) Message-Id: <5FAACDE1-CD71-4740-B56E-AAF426480827@gmail.com> Date: Sat, 12 Dec 2020 13:11:54 -0500 To: bloat X-Mailer: Apple Mail (2.3608.120.23.2.4) Subject: [Bloat] BBR talk from Stony Brook University X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Dec 2020 18:11:57 -0000 Google Alerts for "bufferbloat" pointed to this talk at Stony Brook = University in New York State: Dates: Thursday, December 17, 2020 - 12:30pm to 2:00pm (US EST: UTC-5) Location: Zoom - contact events@cs.stonybrook.edu for Zoom info. Abstract: BBR is a new congestion control algorithm and is seeing = increased adoption especially for video traffic. BBR solves the = bufferbloat problem in legacy loss-based congestion control algorithms = where application performance drops considerably when router buffers are = deep. BBR regulates traffic such that router queues don=E2=80=99t build = up to avoid the bufferbloat problem while still maintaining high = throughput. Though BBR is able to combat bufferbloat for sustained = steady traffic such as large file downloads, our analysis shows that = video applications experience significantly poor performance when using = BBR under deep buffers. In fact, we find that video traffic sees = inflated latencies because of long queues at the router, ultimately = degrading video performance. In this talk, I will present our work on the interaction between BBR and = streaming video. We investigate the relationship between network metrics = such as delay and delivery rate during the video run and the quality of = subsequent video segments. However, we find only weak correlations, = suggesting that another factor is at play. Our empirical investigation = reveals that BBR under deep buffers and high network burstiness severely = overestimates available bandwidth and is slower to converge to steady = state, both of which result in BBR sending substantially more data into = the network, causing a queue buildup. This elevated packet sending rate = under BBR is ultimately caused by the router=E2=80=99s ability to absorb = bursts in traffic, which destabilizes BBR=E2=80=99s bandwidth estimation = and overrides BBR=E2=80=99s expected logic for exiting the startup = phase. Original Notice: = https://www.cs.stonybrook.edu/Rebecca-Drucker-Research-Proficiency-Present= ation-Investigating-BBR-Bufferbloat-Problem-DASH-Video