From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-x236.google.com (mail-oi0-x236.google.com [IPv6:2607:f8b0:4003:c06::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 88BF73B260 for ; Wed, 11 May 2016 12:29:19 -0400 (EDT) Received: by mail-oi0-x236.google.com with SMTP id x201so76460406oif.3 for ; Wed, 11 May 2016 09:29:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-transfer-encoding; bh=+UqABICeIw60k8BcBOGC46gHa7W8GqMD7rAk1YHH6iM=; b=BZ8hoNf02wqKWgxW7BzZ2CGD3J37bre0v5wnHgzOABnNtZhw0zHnPhl3APADGCGGed gTdsjpoqQa25jUW72/ieagKG1eOejHYORril7CqUwcJWHdrpdO2uW3wl2HEbGVqq7IKk SQ1KJ02S1DvHGjMjz06t9pA4F9mqp6/7FcybLE5LphEvQTo0nlXw9ZxyIWHZkp2kMGN9 uCNbpQcTlhHtusRcvMUI9zzlq6uvFfLTJ7qp3sCFMLIdJa+TsXhxFd/VZGCUtVQ2uWI3 NuVSPNKu4YccRkFrgYrcJnR4/mmB3LoGOU6hW9sh85u493HWtio0Byrlft73OJsYV3Fw qOEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-transfer-encoding; bh=+UqABICeIw60k8BcBOGC46gHa7W8GqMD7rAk1YHH6iM=; b=kJe1kT5nvMKNeVZibpcw/t/3ppAT6VUIFM2KxOdAfhVfzgob8DB0FZICv13Flz+LWi FgLIIYVjfGp0okwXxNcjbOAm/jJzTr7/MeFe3dU3imxRuj8IiaU5FtsPm3pvD7cD2ddq R+Ni+8m6t2oAUoZ3pgAwthU5KhBASDgac4KMpfasJrVM7MLeS02WsJ0Sj3GV1ByX4P+X J1VGqKRmndWA1A/rNj9SUWA7BFWNcnj4HeQYfX9baU1yWBcqXNN1IucHc+2Y9npBxYlW aZN+rcb1Gi6bghe1+tK3ytaQ+Uy0OT7Dr+NSv+lcMYsL3FSPzwXxURrq0Xd2GZ6F69Cv VM5w== X-Gm-Message-State: AOPr4FXYde0MWwJ0VGL2meNb2HEbF2UYI+9tYDb0k5uYHTax6bCEqyKnpw/Lm+fxsdAdrPEvRyPBpK9Uv5mrPw== MIME-Version: 1.0 X-Received: by 10.202.186.193 with SMTP id k184mr2725968oif.66.1462984158929; Wed, 11 May 2016 09:29:18 -0700 (PDT) Received: by 10.202.229.210 with HTTP; Wed, 11 May 2016 09:29:18 -0700 (PDT) In-Reply-To: References: <871t58n5wk.fsf@toke.dk> <87futolndh.fsf@toke.dk> <874ma4ljfz.fsf@toke.dk> Date: Wed, 11 May 2016 09:29:18 -0700 Message-ID: From: Dave Taht To: Luca Muscariello Cc: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= , "make-wifi-fast@lists.bufferbloat.net" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Make-wifi-fast] Thoughts on tackling airtime fairness X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 May 2016 16:29:19 -0000 On Wed, May 11, 2016 at 9:19 AM, Dave Taht wrote: > My own foci are going to be around trying to rip every source of > potential latency out of the current system: be it deferred > interrupts, bad rate control information, overlong txops, excessive > retries, insufficient packet loss, busting the block ack window, and > quashing stations grabbing too much airtime... and oh, yea, queuing delay. :) > and then adding back in "bandwidth" from there. We have enough > bandwidth in wifi nowadays, just now narrow enough time slices to feed > many stations sanely. Bandwidth =3D rate/interval. Humans have a terrible tendency to using big intervals, like seconds... I'd like to focus on calculating bandwidth as rate/(minimal achievable txop under contention) rather than maximal. > > a somewhat subtle distinction is that aiming for airtime fairness > independently of the behaviors of real traffic is not a goal (for me). > A system handing out 8 stations 8ms each of airtime is "fair", but > handing out 1ms each - or just enough, for example, for my > videoconferencing flow to handle each frame with a single txop - or > getting a new station started faster on some web traffic - is better. > > Certainly there is a ton of low hanging fruit to excise, and achieving > something closer to airtime fairness is *great* but we ignore multicast, channel scans, and other > oddities to our peril. > > I don't, for example, think that aiming for airtime fairness over 1sec > intervals is good, 20-50ms would be way more desirable. And so on. > Getting a good rate control estimate by the second txop used by a > previously idle station would be good. And so on. > > ... > > this message brought to you from the association for more coffee in the m= orning. losing the www.bufferbloat.net server was not helpful, I'd just booked a vacation ticket. --=20 Dave T=C3=A4ht Let's go make home routers and wifi faster! With better software! http://blog.cerowrt.org