From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yk0-x235.google.com (mail-yk0-x235.google.com [IPv6:2607:f8b0:4002:c07::235]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 3494A21FCB9; Thu, 30 Jul 2015 14:56:24 -0700 (PDT) Received: by ykdv124 with SMTP id v124so4564310ykd.0; Thu, 30 Jul 2015 14:56:24 -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-type; bh=gxfSrDrYQ7sk7tNpEfeRHso5lNogsooX83WyeiH+nwA=; b=oa0LDVQHXoHgPraXCun+yC30g6MWxXrWyfzpGutQDxRKQrqelw4K7hhmna0UW5GQf7 ZrcAoMqdsJNpHncVebrf33ClHLyevIFbm2fmNmR5TOJkmk4mGpJYRbbFP/ZZKkrtoujc /k7XNEUhPMZ61CGXmLM1R4QG8/MlYABSEM6WeGEblK9hM3eNzStoX4ELDLMBS8fWd1SJ m+tVrgpZJ/0HQiDol4r3+Y76C4C4sWAbNE+zFRm+C4NHGTrEmEGC3Pc9d0qRpB6WsAh/ eYCFfrrhHss7UGHOJAAnhN/vDtRx/JVQMk3BKArYf8wIkecCVmzXSNwbOhBP22HiC2P1 vj4w== MIME-Version: 1.0 X-Received: by 10.129.116.134 with SMTP id p128mr53618925ywc.1.1438293383937; Thu, 30 Jul 2015 14:56:23 -0700 (PDT) Received: by 10.37.26.9 with HTTP; Thu, 30 Jul 2015 14:56:23 -0700 (PDT) Received: by 10.37.26.9 with HTTP; Thu, 30 Jul 2015 14:56:23 -0700 (PDT) In-Reply-To: <5CC1DC90-DFAF-4A4D-8204-16CD4E20D6E3@gmx.de> References: <356F5FEE-9FBD-4FF9-AC17-86A642D918A4@gmail.com> <5CC1DC90-DFAF-4A4D-8204-16CD4E20D6E3@gmx.de> Date: Fri, 31 Jul 2015 00:56:23 +0300 Message-ID: From: Jonathan Morton To: Sebastian Moeller Content-Type: multipart/alternative; boundary=001a1147f9ea3b8572051c1ec685 Cc: make-wifi-fast@lists.bufferbloat.net, cerowrt-devel@lists.bufferbloat.net Subject: Re: [Make-wifi-fast] [Cerowrt-devel] [tsvwg] Comments on draft-szigeti-tsvwg-ieee-802-11e X-BeenThere: make-wifi-fast@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Jul 2015 21:56:53 -0000 --001a1147f9ea3b8572051c1ec685 Content-Type: text/plain; charset=UTF-8 Hardware people tend to think in terms of simple priority queues, much like old fashioned military communications (see the original IP precedence spec). Higher priority thus gets higher throughput as well as lower latency. I note also that in 802.11e, leftover space in a TXOP can't be (or at least generally isn't) used opportunistically for traffic from another class, because the four queues are so rigidly separated. I think the hardware people are shortsighted in this respect. It's so easy to game simple priority queues when there's no filter on the field controlling it. That's why cake's Diffserv layer works the way it does. And if I ever get the chance to do a Wi-Fi specific version, I'll avoid both of the above problems. - Jonathan Morton --001a1147f9ea3b8572051c1ec685 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

Hardware people tend to think in terms of simple priority qu= eues, much like old fashioned military communications (see the original IP = precedence spec). Higher priority thus gets higher throughput as well as lo= wer latency.

I note also that in 802.11e, leftover space in a TXOP can= 9;t be (or at least generally isn't) used opportunistically for traffic= from another class, because the four queues are so rigidly separated.

I think the hardware people are shortsighted in this respect= . It's so easy to game simple priority queues when there's no filte= r on the field controlling it. That's why cake's Diffserv layer wor= ks the way it does. And if I ever get the chance to do a Wi-Fi specific ver= sion, I'll avoid both of the above problems.

- Jonathan Morton

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