From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.tuxdriver.com (charlotte.tuxdriver.com [70.61.120.58]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 0C40020045C for ; Tue, 24 May 2011 07:48:38 -0700 (PDT) Received: from uucp by smtp.tuxdriver.com with local-rmail (Exim 4.63) (envelope-from ) id 1QOt6S-0000Jq-TX; Tue, 24 May 2011 11:01:00 -0400 Received: from linville-8530p.local (linville-8530p.local [127.0.0.1]) by linville-8530p.local (8.14.4/8.14.4) with ESMTP id p4OEoFHp022917; Tue, 24 May 2011 10:50:16 -0400 Received: (from linville@localhost) by linville-8530p.local (8.14.4/8.14.4/Submit) id p4OEoFaO022915; Tue, 24 May 2011 10:50:15 -0400 Date: Tue, 24 May 2011 10:50:15 -0400 From: "John W. Linville" To: Dave Taht Subject: Re: still coping with zero packet loss over wireless Message-ID: <20110524145014.GA2504@tuxdriver.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Cc: bloat-devel@lists.bufferbloat.net X-BeenThere: bloat-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: "Developers working on AQM, device drivers, and networking stacks" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 May 2011 14:48:38 -0000 On Tue, May 24, 2011 at 02:46:59PM +0000, Dave Taht wrote: > yesterday I finally got a chance to move a few dozen meters out of the lab > and test the latest build of uberwrt "capetown" and debloat-testing. > > I'd hoped with the debloating techniques in place in capetown - reduced > buffers (4), reduced sw retries (2), hw retries (2, or so I thought) I'd > actually see some packet loss. > > and what I saw instead, was pings that would take as long as 1.6 seconds to > complete, and zero packet loss until I moved completely out of range of the > router. > > I never thought it would be so hard to lose a packet in my life! > > Is there some system tunable, somewhere, in the linux wireless stack that > I've missed, in getting packets to actually fail in 10s of ms? Not one of which I am aware. That sort of thing is going to depend quite a bit on the hardware itself, and it's driver. Maybe some ath9k folk can comment? John -- John W. Linville Someday the world will need a hero, and you linville@tuxdriver.com might be all we have. Be ready.