From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-x235.google.com (mail-qk0-x235.google.com [IPv6:2607:f8b0:400d:c09::235]) (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 0B3B53B2A4 for ; Sun, 1 Oct 2017 22:40:18 -0400 (EDT) Received: by mail-qk0-x235.google.com with SMTP id n5so1752519qke.11 for ; Sun, 01 Oct 2017 19:40:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=YMWY7u0d70qknMN1RBHNKAbNT1VT7wHfL+384Mm4VtI=; b=SCtYVyObc/MZYh0txcu7MUY0SO3/UTMhtGAhDkdIVcCpIqcsh5LSZl7W3ys4Hpd7St ydGsL2b1rl2ap3HtBEKBU4R/eSYyJFLwG+LUnHIHmZLyJjYZ8MX4eYr/P2M3D4FA2ll0 L+SbSHMUO5YfpRGQTfGheDcZbSCNLx23sy1+tR7szsW9bhv6283pGCMInIsq9NsRyn96 ktS7k0Hic2qBihn2ATlLpe3Pi+Wzav/ANR5IpaCfxPj6bg1BrwOEEYb2ASoo7pCuKCgr YKCf5DTmdjQkSnCpex1MhGwBxLw/kUYrnKl8XB1Mebcm5qRJg3OU9cXH2k9v0HKeh7eZ NaNA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=YMWY7u0d70qknMN1RBHNKAbNT1VT7wHfL+384Mm4VtI=; b=nIotgN0IGgySDTm3Q9GBZGh+lKoxEzajmJcTSIISM+I0/7MSz/N/wnecVDpOsZ1OzF Yt0Eqp27/nA2d8E4JtEOnF0PlC++vHLYtikrN4HrHOnskU3wzIHi251s2n7bmVv3qFGz vgvJO3eVtPG+ju1bIU1IJltLbREbBoY6xFVaStt0Dvuirxks0MlaqtvF0s7kbciWXCQV 7VOPglp+dJU/xfVezMazPzAfdwzpTGQkGm2idO228mxlJx/nbsJhX91tNfuzUhk90RFc Gs8+ObxdzpoqzLOR5SxXDkTabNabDstAOFKlcNMQe1oxr95ZvnFjY2WeCF12LCmehKYk SRFA== X-Gm-Message-State: AMCzsaVnnaJnC4epC0ibEhNQwVmGe7+p8iuVj8V36lOhYZFNEbab03l9 +XUZGtTTXGT39kg9L8MhHeoT4hwu9bUD1pBITG8= X-Google-Smtp-Source: AOwi7QAkDhh2OHLwkU653UR4OS7Nas7X9FLvRSnX/Rz7sQCZmi5KghkhRsu0yaYQ++rSLt6RtypQMul2WTcR7H17WqY= X-Received: by 10.55.6.12 with SMTP id 12mr11319327qkg.327.1506912018558; Sun, 01 Oct 2017 19:40:18 -0700 (PDT) MIME-Version: 1.0 Received: by 10.12.195.67 with HTTP; Sun, 1 Oct 2017 19:40:18 -0700 (PDT) In-Reply-To: References: From: Dave Taht Date: Sun, 1 Oct 2017 19:40:18 -0700 Message-ID: To: Jonathan Morton Cc: Cake List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Cake] best way at getting at tcp ack data? X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Oct 2017 02:40:19 -0000 The crux of my question was what would be the best way to incorporate the FLOW_DISSECTOR_KEY_TCP into cake whilst retaining all the other DPI. I would add a "ack_filter" parameter to the rate_flags? On Sun, Oct 1, 2017 at 6:08 PM, Jonathan Morton wro= te: > Ah, so effectively you want to drop acks more aggressively than data pack= ets > when they become a saturating flow in themselves, Well, no, what I envisioned would try to comprehensively "do the right thing" when it came to dropping acks, and not actually wait til they were saturating. you have a good point though. Where I see the most use for it is on very slow DSL, and on wifi (where you have a small packet limit and reliable transfers). I also don't know what will happen with extensive filtering in place to the reverse path, reason tells me that the sparse packet priority scheme when applied to filtered out acks will result in really bursty throughput on the other side, and it would be better to defer a full round between deliveries than leave the sparse packet priority scheme in place, when doing ack filtering. But that's "reason", and that fails me a lot whilst thinking about queues. As I believe at least some level of ack filtering is widely deployed... til now, I've largely been satisfied that the DRR would deliver a ton of acks that would be filtered out by the device doing it. >but without disturbing the > cues that TCP relies on. There is some logic behind that, since COBALT > ramps up quite slowly with very small packets like acks. > > I think it's worth opening an issue to remind me to look into that. Well, I might gather enough gumption to go after it, as well as try and produce a cleaned up cake branch suitable for inclusion in 4.15. At the moment I'm starting to prototype a bit with a bfifo, and perhaps netem, 'cause grokking cake makes my head hurt. > I still > don't have a replacement for my MBP, which is complicating matters here. MBP? > - Jonathan Morton --=20 Dave T=C3=A4ht CEO, TekLibre, LLC http://www.teklibre.com Tel: 1-669-226-2619