From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-11-ewr.dyndns.com (mxout-078-ewr.mailhop.org [216.146.33.78]) by lists.bufferbloat.net (Postfix) with ESMTP id 592802E0392 for ; Tue, 15 Mar 2011 12:59:27 -0700 (PDT) Received: from scan-12-ewr.mailhop.org (scan-12-ewr.local [10.0.141.230]) by mail-11-ewr.dyndns.com (Postfix) with ESMTP id 4FC9D92C303 for ; Tue, 15 Mar 2011 19:59:26 +0000 (UTC) X-Spam-Score: -4.0 (----) X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 15.216.28.35 Received: from g1t0028.austin.hp.com (g1t0028.austin.hp.com [15.216.28.35]) by mail-11-ewr.dyndns.com (Postfix) with ESMTP id 0532192C312 for ; Tue, 15 Mar 2011 19:59:26 +0000 (UTC) Received: from g1t0038.austin.hp.com (g1t0038.austin.hp.com [16.236.32.44]) by g1t0028.austin.hp.com (Postfix) with ESMTP id AC55B1CBF5; Tue, 15 Mar 2011 19:59:25 +0000 (UTC) Received: from [16.89.244.213] (tardy.cup.hp.com [16.89.244.213]) by g1t0038.austin.hp.com (Postfix) with ESMTP id 53D2C3020F; Tue, 15 Mar 2011 19:59:25 +0000 (UTC) From: Rick Jones To: Jonathan Morton In-Reply-To: <29B06777-CC5F-4802-8727-B04F58CDA9E3@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> Content-Type: text/plain; charset="UTF-8" Date: Tue, 15 Mar 2011 12:59:23 -0700 Message-ID: <1300219163.2087.2162.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: Tue, 15 Mar 2011 19:59:27 -0000 On Tue, 2011-03-15 at 21:40 +0200, Jonathan Morton wrote: > On 15 Mar, 2011, at 8:31 pm, John W. Linville wrote: > > > If you don't throttle _both_ > > the _enqueue_ and the _dequeue_, then you could be keeping a nice, > > near-empty tx queue on the host and still have a long, bloated queue > > building at the device. > > Don't devices at least let you query how full their queue is? I believe John is referring to the queue(s) in the intermediate devices. While it may be possible to query the queue lengths there (at one point the MIBs had entries for that) it is still impractical - for one thing, apart from the next-hop device, the host knows nothing about queues out there. Heck, the host may not even know about the next hop device - it could be transparent. rick jones