From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bifrost.lang.hm (lang.hm [66.167.227.134]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id B38A63B2AB; Mon, 21 Mar 2016 21:29:57 -0400 (EDT) Received: from asgard.lang.hm (asgard.lang.hm [10.0.0.100]) by bifrost.lang.hm (8.13.4/8.13.4/Debian-3) with ESMTP id u2M1TriR026484; Mon, 21 Mar 2016 17:29:53 -0800 Date: Mon, 21 Mar 2016 18:29:53 -0700 (PDT) From: David Lang X-X-Sender: dlang@asgard.lang.hm To: Michal Kazior cc: Dave Taht , make-wifi-fast@lists.bufferbloat.net, "codel@lists.bufferbloat.net" In-Reply-To: Message-ID: References: <1456492163-11437-1-git-send-email-michal.kazior@tieto.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Subject: Re: [Codel] [Make-wifi-fast] [RFC/RFT] mac80211: implement fq_codel for software queuing X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Mar 2016 01:29:58 -0000 On Mon, 29 Feb 2016, Michal Kazior wrote: >> Our intent is to continue to improve the flent test suite to be able >> to generate repeatable tests, track relevant wifi behaviors and pull >> relevant data back, graphed over time (of test) and time (over test >> runs). A problem with udp flood tests is that tcp traffic is always >> bidirectional (data vs acks), so a naive thought would be, that yes, >> you should get half the bandwidth you get with a udp flood test. > > I don't see why you'd be doomed to get only half the bandwidth because > of that? Sure, Wi-Fi is half-duplex but transmit time for ACKs is a > lot smaller than transmit time for the data. The difference is actually far less than you think. Each transmission has a fixed-length header and quiet times that were designed in the days of 802.11b (1-11Mb) and if you are transmitting a wide 802.11ac signal at a couple hundred Mb, you can find that the time taken to transmit even full packets is a surprisingly small percentage of the total transmit time. David Lang