From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-14-iad.dyndns.com (mxout-180-iad.mailhop.org [216.146.32.180]) by lists.bufferbloat.net (Postfix) with ESMTP id 6BFAA2E00B9 for ; Sat, 5 Feb 2011 05:42:23 -0800 (PST) Received: from scan-12-iad.mailhop.org (scan-12-iad.local [10.150.0.209]) by mail-14-iad.dyndns.com (Postfix) with ESMTP id 1D7FC44AE0E for ; Sat, 5 Feb 2011 13:42:22 +0000 (UTC) X-Spam-Score: 0.0 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 76.96.30.16 Received: from qmta01.emeryville.ca.mail.comcast.net (qmta01.emeryville.ca.mail.comcast.net [76.96.30.16]) by mail-14-iad.dyndns.com (Postfix) with ESMTP id 5D96344A8B0 for ; Sat, 5 Feb 2011 13:42:21 +0000 (UTC) Received: from omta01.emeryville.ca.mail.comcast.net ([76.96.30.11]) by qmta01.emeryville.ca.mail.comcast.net with comcast id 4Dhb1g0030EPchoA1DiLRE; Sat, 05 Feb 2011 13:42:20 +0000 Received: from [192.168.1.119] ([98.229.99.32]) by omta01.emeryville.ca.mail.comcast.net with comcast id 4DiJ1g00A0hvpMe8MDiKeV; Sat, 05 Feb 2011 13:42:20 +0000 Message-ID: <4D4D53BA.5020003@freedesktop.org> Date: Sat, 05 Feb 2011 08:42:18 -0500 From: Jim Gettys Organization: Bell Labs User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101208 Lightning/1.0b2 Thunderbird/3.1.7 MIME-Version: 1.0 To: bloat@lists.bufferbloat.net References: <20110205132305.GA29396@thyrsus.com> In-Reply-To: <20110205132305.GA29396@thyrsus.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Bloat] First draft of complete "Bufferbloat And You" enclosed. 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: Sat, 05 Feb 2011 13:42:24 -0000 Several reactions: 1) the latency-speed connection needs to be emphasised; along with bandwidth !=speed. You can at least start to attack the conflation of "speed" and "bandwidth" that is in the market. Some highways "meter" car entrance exactly to provide smooth flow on the on ramps and avoid having parking lots (stationary highways). In fact, a highway *is* a parking lot. It has a capacity of stationary cars. But memory is sooo cheap we've paved Texas over with extra road, just in case. 2) classification itself is not evil; but if you don't fix the bloat first, you end with way too much complexity, and and still have problems anyway. At best, you've limited who suffers; at worst, you've made sure the "right" cars haven't suffered here, but when they get to a different part of the network, they'll still suffer (QOS isn't universal, much less your complicated rules). Fix the bloat: then classify. To use the telephone analogy, classification will still result in dropped calls or fast busy, if you aren't on a privileged phone. To use the highway analogy, only a few areas have carpool lanes, and most of the highway is still jammed. Once the carpool lanes are gone (you get to another part of the network), you're still stuck behind miles of traffic. At the end, you've got some problems: First, we don't yet have good solutions for the wireless /variable bandwidth case; we have hopeful avenues we're exploring, Claiming we can fix all of it right now is overstating the problem. We can immediately reduce pain right now, and I hope within a year or three fix it for real. Many people will need to replace their routers, and will believe that is expensive; and to them, buying a $100 router *is* expensive. Remember your audience. And various ISP's aren't going to like the bottom line cost of replacing/upgrading all the broken equipment. - Jim On 02/05/2011 08:23 AM, Eric Raymond wrote: > I consider this draft coverage-complete for the basic introduction I was > aiming at. Suggestions from dtaht5 and jg have been incorporated where > appropriate. Critique and correct, but try not to make it longer. I'm a > bit unhappy about the length and may actually try to cut it. > > You will note that the description of network failure modes is > somewhat broader than in jg's talk. So is the section on why QoS > fails to address the problem. This is me putting on my > system-architect head and doing original analysis; if you think I have > misunderstood the premises or reasoned about them incorrectly, tell > me. > > Please fix typos and outright grammatical errors. If you think you have spotted > a higher-level usage problem or awkwardness, check with me before changing it. > What you think is technically erroneous may be expressive voice. > > Explanation: Style is the contrast between expectation and surprise. > Poets writing metric poetry learn to introduce small breaks in > scansion in order to induce tension-and-release cycles at a higher > level that will hold the reader's interest. The corresponding prose > trick is to bend usage rules or change the register of the writing > slightly away from what the reader unconsciously expects. If you try > to "fix" these you will probably be stepping on an intended effect. > So check first. > > (I will also observe that unless you are already an unusually skilled > writer, you should *not* try to replicate this technique; the risk of > sounding affected or just teeth-jarringly bad is high. As Penn& > Teller puts it, "These stunts are being performed by trained, > *professional* idiots.") > > Future directions: unless somebody stops me, I'm going to reorganize > what wiki docs there are around this thing. The basic idea is to make this > the page new visitors naturally land on *first*, with embedded > hotlinks to the more specialized stuff. > > Explanation: Outlines and bulleted lists of stuff are deadly. They're > great for reference, but they scream "too much; don't read" to people > first trying to wrap their heads around a topic. Narrative > introductions with hotlinks are both less threatening and more > effective. The main reason they're not used more is that most people > find them quite hard to write. I don't. > > If I decide I need to cut the length, I'll push some subsections down > to linked subpages. > > I haven't learned Textile yet. I'll probably get to that this weekend. > > > > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat