From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from tuna.sandelman.ca (tuna.sandelman.ca [209.87.249.19]) (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 ED6FC21FED3; Fri, 31 Jul 2015 13:31:54 -0700 (PDT) Received: from sandelman.ca (obiwan.sandelman.ca [209.87.249.21]) by tuna.sandelman.ca (Postfix) with ESMTP id E92B420620; Fri, 31 Jul 2015 16:40:44 -0400 (EDT) Received: by sandelman.ca (Postfix, from userid 179) id 663DB63AEC; Fri, 31 Jul 2015 16:23:27 -0400 (EDT) Received: from sandelman.ca (localhost [127.0.0.1]) by sandelman.ca (Postfix) with ESMTP id 4EF9763751; Fri, 31 Jul 2015 16:23:27 -0400 (EDT) From: Michael Richardson To: Jonathan Morton In-Reply-To: References: <356F5FEE-9FBD-4FF9-AC17-86A642D918A4@gmail.com> <5CC1DC90-DFAF-4A4D-8204-16CD4E20D6E3@gmx.de> <4D24A497-5784-493D-B409-F704804326A7@gmx.de> <1438361254.45977158@apps.rackspace.com> X-Mailer: MH-E 8.6; nmh 1.3-dev; GNU Emacs 24.4.2 X-Face: $\n1pF)h^`}$H>Hk{L"x@)JS7<%Az}5RyS@k9X%29-lHB$Ti.V>2bi.~ehC0; <'$9xN5Ub# z!G,p`nR&p7Fz@^UXIn156S8.~^@MJ*mMsD7=QFeq%AL4m Sender: mcr@sandelman.ca Cc: make-wifi-fast@lists.bufferbloat.net, cerowrt-devel@lists.bufferbloat.net Subject: Re: [Cerowrt-devel] [Make-wifi-fast] [tsvwg] Comments on draft-szigeti-tsvwg-ieee-802-11e X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 31 Jul 2015 20:32:23 -0000 Jonathan Morton wrote: >> I think that is achievable, *even if there is a WiFi network in the > middle*, by thinking about the fact that the shared airwaves in a WiFi > network behaves like a single link, so all the queues on individual > stations are really *one queue*, and that the optimal behavior of that > link will be achieved if there is at most one packet queued at a time. > I agree that queues should be kept short in general. However I don't > think single packet queues are achievable in the general case. > The general case includes Wi-Fi networks, whose TXOP overhead is so > ruinously heavy that sending single MTU sized packets is > inefficient. Aggregating multiple packets into one TXOP requires those > several packets to be present in the buffer at that moment. Agreed... if one has a minimum of two queues (and *fq-codel has at least that many), why isn't the naive method of: 1) send everything from the low-latency queue 2) send the other stuff until the TXOP is full enough? codel will keep the queues short. The key thing I think, is that the markings (1)/(2) above be passed along through all "subqueues"...