From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x22f.google.com (mail-lj1-x22f.google.com [IPv6:2a00:1450:4864:20::22f]) (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 9C3FC3BA8E for ; Tue, 28 Aug 2018 20:16:46 -0400 (EDT) Received: by mail-lj1-x22f.google.com with SMTP id l15-v6so2890779lji.6 for ; Tue, 28 Aug 2018 17:16:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=OOhpqMtuhtBlqa3XKbdBTYwuqswC57QMdkegd0mUnt4=; b=uxwj10PnSo5JE9alz17PrSaYyIxY6+E/SSY0HfMkI6LUXoihQ3eAaQirPyKq+xpd/N mKH/7n3JfvKQC9WL5UFoXqI1IE2VPEGMaPV2Z7B+UWMsy5ZFTeUH6FtzRoolmYYXNSc5 JWncPAnXmcXVI24L9gwjIFNuW3GUwoAvK9Qo93HvFxyqP0BDUd/ECEWnIcL0Zd6rHyjD bSAQlWlgm/qnGU8OOSwMzSezK4hIcGof0rFzm3wA9rQXZLghdjy3JGOyKYLzVg66CUvy 67bodGmYO7tF5DW5r/VNCAQXRbzVNFv+Mg/kwq8fXFVJhxfYwgk7IYf2MlEwToSxhxNY sEGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=OOhpqMtuhtBlqa3XKbdBTYwuqswC57QMdkegd0mUnt4=; b=BlUHv2+7KNA7CyJmCQwO05JvUUwO5z3dilQ0muHsjtjZElQEfLBtU2RTCaj5JpimuS LkPfwF8DgD03DkuCGXebWPgZjchKjmHc7cBIYlaAI5CCBygNp+Rxutv0zW40SgbDMwdu HhwYlAy4uuM4VkMgyEbfyj+6MPje/eNXdYVW3LMp5kvtTG7JzQJaalYzrgXUYQMQpz/K sfiaE2cJEiagIFEhxwnXGB7tp/kPT+N1o7sCx9hxBi3Kxbf/6crdc82ABYKyJHNBvbML 870vJWXi2c1zNFeesBAlCekPPsvqyZiyPNFbtkpsYafhM8x1NrVXYUGxTQvzniJGGkHb Ou/w== X-Gm-Message-State: APzg51CuMKRJFHihjk0qq2cpJFR1VKJDrfquUf1AMMiu+9C2Qzf0JIa1 F2W/py10mmOb+M4IlgA3oCc= X-Google-Smtp-Source: ANB0Vdb351WWtRKODZP0/woOIuBEoN9ASHgkFu6fGwScNNoNGgYtT2chtpFjGypGztr7hnDUZa9Kzw== X-Received: by 2002:a2e:259:: with SMTP id 86-v6mr2717995ljc.107.1535501805516; Tue, 28 Aug 2018 17:16:45 -0700 (PDT) Received: from jonathartonsmbp.lan (83-245-238-14-nat-p.elisa-mobile.fi. [83.245.238.14]) by smtp.gmail.com with ESMTPSA id 103-v6sm287135lfs.28.2018.08.28.17.16.44 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Aug 2018 17:16:44 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) From: Jonathan Morton In-Reply-To: <2385fcbb-d460-ce57-e4e3-e3cbb94ebc3d@rogers.com> Date: Wed, 29 Aug 2018 03:16:43 +0300 Cc: bloat@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: References: <2385fcbb-d460-ce57-e4e3-e3cbb94ebc3d@rogers.com> To: davecb@spamcop.net X-Mailer: Apple Mail (2.3445.9.1) Subject: Re: [Bloat] an observation from the field 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: Wed, 29 Aug 2018 00:16:46 -0000 > On 29 Aug, 2018, at 2:53 am, David Collier-Brown = wrote: >=20 > Humans experience delays directly, and so perceive systems with high = latency as "slow". The proverbial "man on the Clapham omnibus" therefor = responds to high-latency systems with disgust. >=20 > A trained scientist, however, runs the risk of choosing something that = requires complicated measurement schemes, and might well choose to = optimize for throughput, as that sounds like a desirable measure, one = matching their intuitions of what "fast" means. The correct approach, for scientists, is to observe that for many = applications, response time (a form of latency) is the *only* relevant = metric. In some cases, higher bandwidth correlates with reduced = response time, such as for software updates. In other cases, bandwidth = is essentially irrelevant, except as it pertains to serialisation delay = of single packets. Conversely, there are some applications for which sufficient bandwidth = is not a matter of response time, but a threshold prerequisite for = correct operation. We can refer to these as isochronous applications, = or choose another term if you prefer. Video streaming is an example of = this; given an a-priori chosen video codec setting, if the data it = produces cannot be transferred as fast as it is produced, the receiver = will not be able to play it back in synchrony. YouTube can reliably stream Full-HD (1080p60) video down a 10Mbps = debloated pipe. The broadband standard in the US claims that 25Mbps is = necessary for this precise application. Draw your own conclusions. - Jonathan Morton