From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x243.google.com (mail-qk0-x243.google.com [IPv6:2607:f8b0:400d:c09::243]) (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 1F16B3B2A0; Tue, 15 Nov 2016 12:01:32 -0500 (EST) Received: by mail-qk0-x243.google.com with SMTP id n204so17262308qke.2; Tue, 15 Nov 2016 09:01:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:content-transfer-encoding:subject:message-id:date:to :mime-version; bh=RrLZx5BaaG9b5s2GswQzvXhopO4+IDpLm5W4jSgbB7A=; b=AK9vmSFRByQZ7tdeF/dIGoh3gTCE6wNtK1GJ6nK7nJZjXlt2YuGmm61IAP5tGVdKLA J6beyT/v37XA0Wp/mLhAqt+N2hqQqDWri88+gqcjom9bD7gm5/WySIQ6luwR4+YPA2uR 5LUAZcah1QI0MlNGRuf7eubaQWnJG/1Db0Sa6h6aCQKpDsQITGWCVLuVanpSIwLDZQv6 jyXhj5ytho5Q2mLRWHk3VZjyfgpKF/q9f0jM6naPP+ubYris3sFqFdknwUxZeaf+BGjl Kg/Ajk6BfqdURtY0pukSjABNtAIo/ZJFo3NZgVmP0HhoeGUOSi1xLULsHhzv6aH41wOc PSPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:content-transfer-encoding:subject :message-id:date:to:mime-version; bh=RrLZx5BaaG9b5s2GswQzvXhopO4+IDpLm5W4jSgbB7A=; b=bTR+DLsJA87FzYIuMS82GfsJpkrGXmF8b7rZ7zk4pGhtiXMykv9Zh4OIyzWAFi89xZ MtIAp0JW7H23G3ApAwCczlGJpxhsJRhERI9VahjPndJb+Oh58JsXkMtjHQYLh2V8iP4V s6c1fjxBVQy0P/XhBN5ribWoUxTLeQGRXv9fymWXAa13n/59JgIsaCpPsJwjasVfc41M sLTvwA8c50j909X+A9LDhR0INXyYNJYzgeb1I9zE3xdNqvL9bvay4Pg+KQgpDEmlh1XF z6s5VgSGA1gyj9X5WnlqU06913HQyNYIMdXGkXv451f4D/p4ZA2hjAXLcm+28S1K012k K3Lg== X-Gm-Message-State: ABUngvfcnmSH0xYjVRgDcV1Om8MWzGCXA+XXghNRmenlh59HSZiMnZnvvg3OOpRj+4Oyng== X-Received: by 10.55.49.203 with SMTP id x194mr27239570qkx.93.1479229291510; Tue, 15 Nov 2016 09:01:31 -0800 (PST) Received: from richs-mbp-5989.home.lan (pool-64-223-235-211.port.east.myfairpoint.net. [64.223.235.211]) by smtp.gmail.com with ESMTPSA id q53sm15557958qtq.0.2016.11.15.09.01.30 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 15 Nov 2016 09:01:30 -0800 (PST) From: Rich Brown Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Message-Id: <156EE814-3742-4F23-99AC-7905077B1803@gmail.com> Date: Tue, 15 Nov 2016 12:00:29 -0500 To: bloat , make-wifi-fast@lists.bufferbloat.net Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2104\)) X-Mailer: Apple Mail (2.2104) Subject: [Make-wifi-fast] QCut - "Understanding on-device bufferbloat for cellular upload", Guo et al 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: Tue, 15 Nov 2016 17:01:32 -0000 Google Alerts sent a link to this paper: "Understanding on-device = bufferbloat for cellular upload" available at: = http://dl.acm.org/citation.cfm?id=3D2987490 (ACM Paywall...) In my two-minute skim of the paper, I see they describe how latency gets = bad on cellular devices (no kidding) and then propose QCut, a queue = inserted between the qdisc and the hardware. They say: --- ... QCut operates in the kernel space and takes as input only = information of buffer occupancy and transmission statistics, which is = exposed by most cellular radio firmware from Qualcomm and likely other = vendors. Since directly limiting the firmware buffer occupancy is difficult, QCut = controls the firmware queuing delay indirectly in the kernel by = controlling how fast packets from Qdisc flow into the firmware buffer. = QCUT estimates the radio firmware buffer occupancy and queuing delay to = decide the transmission of packets to the firmware dynamically... --- Their analysis and charts show that QCut helps a lot. I found it interesting that they make measurements with both weak and = strong signal strength, to indicate the hits that are caused by = differing signal strength. Enjoy! Rich=