From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-x230.google.com (mail-lf0-x230.google.com [IPv6:2a00:1450:4010:c07::230]) (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 CDB033B2A4 for ; Thu, 21 Jun 2018 12:54:11 -0400 (EDT) Received: by mail-lf0-x230.google.com with SMTP id e13-v6so5349904lfc.1 for ; Thu, 21 Jun 2018 09:54:11 -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=RtYBOUEwKqbL6AyQRLZtg0Ma5YTgrQYDp4g3gI9MjhI=; b=gs3/0m48eFWi9rpwwrz7pvCKWSR9ftZD3veIlg6IUYjs4g9WdFDAdpJTGjVVLFD6Um qL8WKMGrrHUKIkkaoF3HzbGX8h1OKSuCyZeQ8JWt1v3UHEnfKctNEFBEa9Ebb7/5Yn6l HM63CooVsW63Xi7oEIi+eLyI+Q/pixRDi9/YifeO5Jh8y+nZ84YjGjUdjZen/tUnofmN 5hkVs2xwaeygi8up8Bo8gXyDOhZqYJNgvGYGjqiOZkro+3LMhcAJaLJAgBcNi2eVaB+k oQvDObZryc5QqubaV2ytUwPR9IkySB5GaKnfaBWUgo1o53e/a/qPLZYxyLZZLFy5ILap 8Z3g== 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=RtYBOUEwKqbL6AyQRLZtg0Ma5YTgrQYDp4g3gI9MjhI=; b=JWd67ajpft/TYlTIkMujnTn1HjZ4lsB1HEuZ3+XElEdhO7VFvOUaLgqc4wx8pNlYcK rRYxTve5FHcCHSgRnWS8/7KXdwRDwKLG7Kruinm3Nzkm3ZdBVcytAxv10Yx2KtJ5petn p9qmYidaTZTC4jxScxfa26I/3kHIl9wzPJOfBHIoXn3o1BoSxkh5OoeWGMvh/PDvntux RZbyI3IZiee0kpW49S3hWcv12s3pt2D4mG2g7hqr2Nq63JHzxsuW69YGhJzBlQGL3NWd xQyR1iZdsaPt913oPIFr0XCiFnS+1Ft0EGGPNBpzBHZyeSP9WJTLguEKMRt/ZYbOUoMo 8tRw== X-Gm-Message-State: APt69E0gIZBLCHuHJP4036hh7SWIaonZDnYVnxdoxxPN+1NHh5Wmtiw+ kzroNZfsiYxGmABKsb5ykIw= X-Google-Smtp-Source: ADUXVKLhBYdZoMIEOImi5KzQ2xPVcT6EavvlMGLgzIcTCLdzoDoKoPol0hr6hNdsug8wl6UVGhd7gg== X-Received: by 2002:a19:d405:: with SMTP id l5-v6mr14559496lfg.28.1529600050675; Thu, 21 Jun 2018 09:54:10 -0700 (PDT) Received: from [192.168.239.105] (83-245-237-65-nat-p.elisa-mobile.fi. [83.245.237.65]) by smtp.gmail.com with ESMTPSA id d25-v6sm1034458lfl.82.2018.06.21.09.54.09 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Jun 2018 09:54:10 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.4 \(3445.8.2\)) From: Jonathan Morton In-Reply-To: <870e30f7-05bd-7d4d-e3d7-937f815a74c4@rogers.com> Date: Thu, 21 Jun 2018 19:54:08 +0300 Cc: bloat@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <469BADBF-DA3B-4875-B278-5EEF0A568FB9@gmail.com> References: <8736xgsdcp.fsf@toke.dk> <838b212e-7a8c-6139-1306-9e60bfda926b@gmail.com> <870e30f7-05bd-7d4d-e3d7-937f815a74c4@rogers.com> To: davecb@spamcop.net X-Mailer: Apple Mail (2.3445.8.2) Subject: Re: [Bloat] lwn.net's tcp small queues vs wifi aggregation solved 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: Thu, 21 Jun 2018 16:54:12 -0000 >> This is a case where inserting a teeny bit more latency to fill up = the >> queue (ugh!), or a driver having some way to ask the probability of >> seeing more data in the >> next 10us, or... something like that, could help. >=20 > Hmmn, that sounds like a pattern seen in physical switching systems: = someone with knowledge that another car is coming (especially if it's = unexpected) waves a flag at the dispatcher to warn them to leave space = and avoid a nasty ka-thump and the extra strain on the couplers (;-)) A more relevant railway analogy would be that a passenger train keeps = its doors open while waiting for the departure signal to clear, = permitting more passengers to board. At large stations the crew will = press a TRTS (Train Ready To Start) button on the platform about half a = minute before departure time, to prompt setting of the departure route = in time, but a conflicting movement may delay the signal actually = clearing. - Jonathan Morton