From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from korolev.univ-paris7.fr (korolev.univ-paris7.fr [IPv6:2001:660:3301:8000::1:2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 6E0DF3B25D; Thu, 28 Apr 2016 10:59:56 -0400 (EDT) Received: from mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [81.194.30.253]) by korolev.univ-paris7.fr (8.14.4/8.14.4/relay1/56228) with ESMTP id u3SExlaa027168; Thu, 28 Apr 2016 16:59:47 +0200 Received: from mailhub.math.univ-paris-diderot.fr (localhost [127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTP id 2ABCD62088; Thu, 28 Apr 2016 16:59:47 +0200 (CEST) X-Virus-Scanned: amavisd-new at math.univ-paris-diderot.fr Received: from mailhub.math.univ-paris-diderot.fr ([127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id GpHBZ-Pr5t6x; Thu, 28 Apr 2016 16:59:45 +0200 (CEST) Received: from lanthane.pps.univ-paris-diderot.fr (unknown [172.23.36.54]) (Authenticated sender: jch) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTPSA id A58D66207E; Thu, 28 Apr 2016 16:59:45 +0200 (CEST) Received: from localhost ([::1] helo=lanthane.pps.univ-paris-diderot.fr) by lanthane.pps.univ-paris-diderot.fr with esmtp (Exim 4.86_2) (envelope-from ) id 1avnPt-0001NS-CU; Thu, 28 Apr 2016 16:59:45 +0200 Date: Thu, 28 Apr 2016 16:59:45 +0200 Message-ID: <7ih9el3hjy.wl-jch@pps.univ-paris-diderot.fr> From: Juliusz Chroboczek To: dpreed@reed.com Cc: "=?utf-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?=" , make-wifi-fast@lists.bufferbloat.net, "babel-users@lists.alioth.debian.org" , "cerowrt-devel@lists.bufferbloat.net" In-Reply-To: <1461853008.891910506@apps.rackspace.com> References: <1461849006.60252745@apps.rackspace.com> <87oa8tyhug.wl-jch@pps.univ-paris-diderot.fr> <878tzx4zno.fsf@toke.dk> <1461853008.891910506@apps.rackspace.com> User-Agent: Wanderlust/2.15.9 MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (korolev.univ-paris7.fr [194.254.61.138]); Thu, 28 Apr 2016 16:59:47 +0200 (CEST) X-Miltered: at korolev with ID 57222563.000 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)! X-j-chkmail-Enveloppe: 57222563.000 from mailhub.math.univ-paris-diderot.fr/mailhub.math.univ-paris-diderot.fr/null/mailhub.math.univ-paris-diderot.fr/ X-j-chkmail-Score: MSGID : 57222563.000 on korolev.univ-paris7.fr : j-chkmail score : . : R=. U=. O=. B=0.000 -> S=0.000 X-j-chkmail-Status: Ham Subject: Re: [Make-wifi-fast] [Babel-users] perverse powersave bug with sta/ap mode 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: Thu, 28 Apr 2016 14:59:56 -0000 > Discovery is a special case, that is not quite multicast. [...] So you > don't need any facility to "reach all" in one message. Are we speaking of the IP Internet, or of some other network? A number of fundamental Internet protocols, such as ARP and ND, use multicast for discovery (I see broadcast as a special case of multicast). So if you want to implement the TCP/IP suite, your link layer needs to support multicast. Some people have tried to work around that (see RFC 2022, for example), with IMHO little success. What you seem to be arguing is that it would be possible to design a protocol suite that uses anycast for discovery. While an interesting research project, your suite would no longer be TCP/IP, good luck getting it deployed. (So what's the solution? As Toke suggested, push the multicast implementation to the link layer -- have the link layer convert multicast to multiple unicasts in a way that's invisible to the network layer. After all, that's what the link layer is for -- hiding the idiosyncrasies of a given physical layer from the network layer.) -- Juliusz