From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-12-iad.dyndns.com (mxout-042-iad.mailhop.org [216.146.32.42]) by lists.bufferbloat.net (Postfix) with ESMTP id 8CBA32E00B9 for ; Thu, 17 Mar 2011 11:22:20 -0700 (PDT) Received: from scan-11-iad.mailhop.org (scan-11-iad.local [10.150.0.208]) by mail-12-iad.dyndns.com (Postfix) with ESMTP id 1C0BF36FDCA for ; Thu, 17 Mar 2011 18:22:19 +0000 (UTC) X-Spam-Score: -4.0 (----) X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 15.193.32.61 Received: from g6t0184.atlanta.hp.com (g6t0184.atlanta.hp.com [15.193.32.61]) by mail-12-iad.dyndns.com (Postfix) with ESMTP id BA5CA370399 for ; Thu, 17 Mar 2011 18:22:18 +0000 (UTC) Received: from g5t0029.atlanta.hp.com (g5t0029.atlanta.hp.com [16.228.8.141]) by g6t0184.atlanta.hp.com (Postfix) with ESMTP id 71648C0C4; Thu, 17 Mar 2011 18:22:15 +0000 (UTC) Received: from [16.89.244.213] (tardy.cup.hp.com [16.89.244.213]) by g5t0029.atlanta.hp.com (Postfix) with ESMTP id B94C220125; Thu, 17 Mar 2011 18:22:14 +0000 (UTC) From: Rick Jones To: Jonathan Morton In-Reply-To: <66469263-763A-4D5A-B689-026D0603C170@gmail.com> References: <4D7F4121.40307@freedesktop.org> <20110315175942.GA10064@goldfish> <1300212877.2087.2155.camel@tardy> <20110315183111.GB2542@tuxdriver.com> <29B06777-CC5F-4802-8727-B04F58CDA9E3@gmail.com> <20110315205146.GF2542@tuxdriver.com> <219C7840-ED79-49EA-929D-96C5A6200401@gmail.com> <20110316004722.GD28663@tuxdriver.com> <66469263-763A-4D5A-B689-026D0603C170@gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 17 Mar 2011 11:22:12 -0700 Message-ID: <1300386132.2087.2345.camel@tardy> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Cc: bloat@lists.bufferbloat.net Subject: Re: [Bloat] Random idea in reaction to all the discussion of TCP flavours - timestamps? X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list Reply-To: rick.jones2@hp.com List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Mar 2011 18:22:20 -0000 On Thu, 2011-03-17 at 04:26 +0200, Jonathan Morton wrote: > For the benefit of the 3G folks, here are some helpful axioms to discuss: > > 1) Buffering more than a couple of seconds of data (without employing > AQM) is unhelpful, and will actually increase network load without > increasing goodput. Unless there is a compelling reason, you should > try to buffer less than a second. > > This is because congestion and packet-loss information takes longer to > influence existing flows, and new flows are more difficult to start. > After about 3 seconds of no information, most TCPs will start > retransmission - regardless of whether the packets were physically > lost, or are simply languishing in a multi-megabyte buffer somewhere. So initialRTO is specced currently to be 3 seconds, with a small but non-trivial effort under way to reduce that, but once established connections have a minimum RTO of less than or equal to a second don't they? rick jones