From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-x229.google.com (mail-oi0-x229.google.com [IPv6:2607:f8b0:4003:c06::229]) (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 BC1663B25D; Thu, 28 Apr 2016 14:04:23 -0400 (EDT) Received: by mail-oi0-x229.google.com with SMTP id v145so59194648oie.0; Thu, 28 Apr 2016 11:04:23 -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=RSmSzyXVy/z7SRT7ZvK3Rm0Cu8xiFUrp3A9FU7Rv9cc=; b=ikseWIj1s0adpH28Vilubikk8p5+QPmZoz7RVg3bbT3EtmhEcYqTLIqQq4yz1zSlwd bHZV+vN3A2qaq6xY37q7n0nBJjfbR0Hzv3I92+fnACKVAzaM0IAcgyNG1cBUiQLJ4J9y o8HtpQyE9ZGHwzl4Tlk1hEsxcO0rVqrsoZ4WZyVn6qXz1uuvNaoXI9Cvbwg1o2KwjBdh kyBOqo9dK+WLIh/uD8j3M4JVsjQVNoNJ7vfhKWyG3KMWKpku5CLNTaz/4F9097ooHvNY zRYTJjBkozC4ZIY9WkuM7A3/trsmBysfvIelRYDdbd1BEm7PMLMZ6VIhsnNl8mvOt4CG BA6w== 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=RSmSzyXVy/z7SRT7ZvK3Rm0Cu8xiFUrp3A9FU7Rv9cc=; b=f6gCEQhSiTKD7BIlNSuTh2IuMW5kGun4SwinM5JlTkJL+pgV0M0Uq9f8BNwC8USyKw 3q18mETHCGTC+rJVz0Apjd5Fy5oyFvjtMgQsPNrkbzLnxiqAdgdg9NSyISns74ltER56 qDYANrb9daEDp2UCdzErR3kqqTauQU98wihRjwYB1fIpwxDWTuasfnSRvcpYcgqG6Kqn mQFDpVcI3iSgEgOFkZYOdDqPJlUNLf8B+Pu08gbpS1tTpfKYjrjkBYikVLJ8q5xTbtVt NH4xZ62Zpox4Ue6rOKpnHXwt4OD1FK17B3T+sxq4+lfjXViGohyeMQ+p6s2UXizyUT7s tRXg== X-Gm-Message-State: AOPr4FVXoXZQwPz76k7vHk7NDbViAwabl3OAs1wIpUxKmeIhQX9RxwMjwSi6cSKBTRFkT2Ct//t1ejbM16GmIQ== MIME-Version: 1.0 X-Received: by 10.157.52.162 with SMTP id g31mr7883387otc.165.1461866663213; Thu, 28 Apr 2016 11:04:23 -0700 (PDT) Received: by 10.202.78.23 with HTTP; Thu, 28 Apr 2016 11:04:23 -0700 (PDT) In-Reply-To: <7ibn4t3bhi.wl-jch@pps.univ-paris-diderot.fr> References: <1461849006.60252745@apps.rackspace.com> <87oa8tyhug.wl-jch@pps.univ-paris-diderot.fr> <878tzx4zno.fsf@toke.dk> <1461853008.891910506@apps.rackspace.com> <7ih9el3hjy.wl-jch@pps.univ-paris-diderot.fr> <7ibn4t3bhi.wl-jch@pps.univ-paris-diderot.fr> Date: Thu, 28 Apr 2016 11:04:23 -0700 Message-ID: From: Dave Taht To: Juliusz Chroboczek Cc: make-wifi-fast@lists.bufferbloat.net, "babel-users@lists.alioth.debian.org" , "cerowrt-devel@lists.bufferbloat.net" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Cerowrt-devel] Multicast IHUs [was: perverse powersave bug with sta/ap mode] X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.20 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: Thu, 28 Apr 2016 18:04:23 -0000 On Thu, Apr 28, 2016 at 10:10 AM, Juliusz Chroboczek wrote: >> 4) And ya know - it might merely be a (sadly common) bug. Everybody's >> supposed to wake up for the multicast beacons and get a notification >> there's more data to come. > > Yes, it's obviously a bug. Just like you, I'm not suprised -- ad-hoc mod= e > and power save is the kind of thing that's never tested. No, this is the kind of thing that normal users of wifi use - AP/station mode being the most common mode of operation. adhoc - rarely functional or tested power save - VERY tested for people that want to save major power, which is everybody running on battery, pulling out every trick (even dubious ones) to meet consumption goals (rather than network connectivity goals). I do not know to what extent or where the problem I am seeing is actually happening, I can look at the multicast beacons harder to see what's going on. Wifi powersave is not "go to sleep entirely", it is "please wake up on this schedule (250ms) so I can poke you with more unicast data if I have any, it also requires (in the spec) that buffering the accumulated packets be done til that beacon, and multicast packets are supposed to be sent as CAB ("crap after beacon" in ath9k's documentation, content after beacon, elsewhere). The "buffering til you wake up" requirement is hell on trying to roll a airtime fairness scheduler, or codel, in stack portions.... Certainly many devices simply disassociate when they go to sleep nowadays. --=20 Dave T=C3=A4ht Let's go make home routers and wifi faster! With better software! http://blog.cerowrt.org