From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x22a.google.com (mail-lj1-x22a.google.com [IPv6:2a00:1450:4864:20::22a]) (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 06A653CB37 for ; Sun, 7 Apr 2019 15:11:19 -0400 (EDT) Received: by mail-lj1-x22a.google.com with SMTP id f18so9265748lja.10 for ; Sun, 07 Apr 2019 12:11:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=umich.edu; s=google-2016-06-03; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=t7MNg1gllLBZJeXJxl82PvRffmTrBnKVuMLHueIBoOY=; b=HxW3rrqJUSADQh/+xGT3xcroRX3JagLyS9zQEw133hO+qPBWKnNzPle0SWD06znN3Q HneVC+KcZlJuOwZWCrLMCen4YytXrzlMNyexzN5RviEzPnI2GbglHiq3N/OtfS6BTFGP Pe+A0Jcw5ogw9q79+qhVZy4S9csy99t7+W5Kym+PiYdpIpFvXbOzbJAFdVlBJ3XdDr3b BZ4KQXYZSxFLLuJhnqtKkfVjgrRrLyPAKYKk256vk1lEp7NNsGiO2VLzPm3zccjHSXfo Srr7O+nsOgjZ/Irjn24BUd6hx189lergwer3+8QIpt4TTGo+gEl1gomVXOzeG1rXvNc4 J9yg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=t7MNg1gllLBZJeXJxl82PvRffmTrBnKVuMLHueIBoOY=; b=J29yOF4irC7d4WSWrKAfRZzKpLPXKA7WwY/vX4DJOf9zXMAx8uQkuI3c8HA7EFco5+ Nz+8Iaz06d//6fTxV/DWsR4NMyiXXizt2m3QtdFB9daBYdGxrOPmSiedS+Bp9oRhebwj ftm92+FTvAQ9rq218TjWBSR139dlCZyyYjG1jP21Bnn5G3kvAEJaBMImlFHSFzFMNWZF 9hUiXnm5XR5XCXvlqWguLX5DMbJ8lcB3dl1vWUK1zJU4aDohHHEi6OomznnHWM3GZjrV CMFlOQRV9IIB+zeDhYpubfmNx2vkMwp9q7wWsSWtgM3XWMRll0XjiFP9sfkPAqusXw6+ sZhg== X-Gm-Message-State: APjAAAVe2BipItYS9Ram8boQgJwnQDPZTR/lC7JzZHI6j6D3iIvnWRj5 YSbMe7bTiODMGzJPtvCQdRxy5WQfhefKk9WM8VumpQ== X-Google-Smtp-Source: APXvYqx5muQ7g0HWTQmnCOUVI3oYgIb8NkjvuFfPmuEZhI1M7ETU26AxA3GcSjla8nbxO2fxJQJI5RT3Kz28wbHMWh0= X-Received: by 2002:a05:651c:157:: with SMTP id c23mr13485070ljd.151.1554664278760; Sun, 07 Apr 2019 12:11:18 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Xiao Zhu Date: Sun, 7 Apr 2019 15:11:07 -0400 Message-ID: To: Dave Taht Cc: Make-Wifi-fast , "Z. Morley Mao" Content-Type: multipart/alternative; boundary="00000000000014ab490585f57c04" X-Mailman-Approved-At: Sun, 07 Apr 2019 17:16:02 -0400 Subject: Re: [Make-wifi-fast] 30+ sec of miserable bufferbloat in wearOS X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 07 Apr 2019 19:11:20 -0000 --00000000000014ab490585f57c04 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear Dave Taht, Thank you for pointing out those two great papers and paying attention to our recent work. In the context of wearable networking where the bottleneck is the Bluetooth link between the smartphone and the smartwatch, the solutions you mentioned can conceptually help to handle bottleneck queuing at lower layers, but it could be hard to execute them given the Bluetooth stack in Android is very different from that of WiFi/LTE and does not speak TCP/IP. In our future bufferbloat-related work, we will definitely discuss more related works, especially those you mentioned. Best, Xiao On Sat, Apr 6, 2019 at 8:14 PM Dave Taht wrote: > "When acting as a gateway proxy for a wearable, the phone dramatically > inflates the end-to-end (server to wearable) latency to 30+ seconds > due to its incurred =E2=80=9Cbufferbloat=E2=80=9D. We then break down the= end-to-end > latency into various components, and identify the root cause to be the > phone-side TCP receive buffer, whose configuration does not take into > account the path asymmetry between the wearable-phone path and the > phone-server path... " - > https://anikravesh.github.io/files/wearos-sigmetrics19.pdf > > I am of course puzzled as to why they didn't look into sch_cake[1] or > fq_codel derived solutions[2], (it is a non-open source OS) but they > did manage to eliminate 97% of the problem in their paper, so, there's > that. > > [1] https://arxiv.org/abs/1804.07617 > [2] > https://www.usenix.org/system/files/conference/atc17/atc17-hoiland-jorgen= sen.pdf > -- > > Dave T=C3=A4ht > CTO, TekLibre, LLC > http://www.teklibre.com > Tel: 1-831-205-9740 > --=20 Xiao (Shawn) Zhu PhD Candidate, Computer Science & Engineering University of Michigan, Ann Arbor, MI 48105 Email: shawnzhu@umich.edu Phone: 734-263-0338 --00000000000014ab490585f57c04 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear Dave Taht,

Thank you for pointing = out those two great papers and paying attention to our recent work.=C2=A0

In the context of wearable networking where the bot= tleneck is the Bluetooth link between the smartphone and the smartwatch, th= e solutions you mentioned can conceptually help to=C2=A0handle bottleneck q= ueuing at lower layers, but it could be hard to execute them given the Blue= tooth stack in Android is very different from that of WiFi/LTE and does not= speak TCP/IP.=C2=A0

In our future bufferbloat-rel= ated work, we will definitely discuss more related works, especially those = you mentioned.=C2=A0


Best,
Xiao

On Sat, Apr 6, 2019 at 8:14 PM Dave Taht <dave.taht@gmail.com> wrote:
"When acting= as a gateway proxy for a wearable, the phone dramatically
inflates the end-to-end (server to wearable) latency to 30+ seconds
due to its incurred =E2=80=9Cbufferbloat=E2=80=9D. We then break down the e= nd-to-end
latency into various components, and identify the root cause to be the
phone-side TCP receive buffer, whose configuration does not take into
account the path asymmetry between the wearable-phone path and the
phone-server path... " -
https://anikravesh.github.io/files/wearos= -sigmetrics19.pdf

I am of course puzzled as to why they didn't look into sch_cake[1] or fq_codel derived solutions[2], (it is a non-open source OS) but they
did manage to eliminate 97% of the problem in their paper, so, there's<= br> that.

[1] https://arxiv.org/abs/1804.07617
[2] https://www.usen= ix.org/system/files/conference/atc17/atc17-hoiland-jorgensen.pdf
--

Dave T=C3=A4ht
CTO, TekLibre, LLC
ht= tp://www.teklibre.com
Tel: 1-831-205-9740


--
Xiao (Shawn) Zhu
PhD Candidate, Comp= uter Science & Engineering
University of Michigan,=C2=A0Ann Arbor, MI 48105
Phone:=C2=A0734-263-0338
--00000000000014ab490585f57c04--