From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x82f.google.com (mail-qt1-x82f.google.com [IPv6:2607:f8b0:4864:20::82f]) (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 9157D3BA8E for ; Fri, 30 Nov 2018 14:02:47 -0500 (EST) Received: by mail-qt1-x82f.google.com with SMTP id d19so7069071qtq.9 for ; Fri, 30 Nov 2018 11:02:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=wVTTPcLeWwsRDEr/B5+1gRp6VIMrj8ehwljqKHcF9Uw=; b=AWqkVz/6q4EPVt6LYG3t7Gdsp18dzmHAWWKPc5tLkf5xXV07Xm8ZuP3CBqzVsUwLfa foUOmIQHfg3HXZMalhrgXfZjgyDuI1EEDt/A//wwb1GkbzM034Lk3sgHbNs3erlTJ3F+ oI8sGX4KfpqLbqzYYOgFVmgVcc315wy5AsFT8CablYHyWYs1NwZ9ExOu1hoVCNGIdkuL /bURniV17vyFhk6vKjuDR9bfuC3PEwsbcUdhsUdI70QN8Pgb/NgXwpeGjLkLazWPz94p kuk6+ZKRJIO0t/P1x1x5Ouf5cUZRo0q5V73LVZncS1rC5dWKSCGZU3bju+aonOzz0msk aTCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=wVTTPcLeWwsRDEr/B5+1gRp6VIMrj8ehwljqKHcF9Uw=; b=sG72aAoQQwa8ORTMov/DvPqvqNvkOEPbDuBEclH/F/VpW8l8QF1RAw1+h0RxDbaHUO KBDtnxy0OIfYiwT9NhQb0aIaZpDy1RASHMNu2/c8sFAsZ0+xsO07Vu2sRnkIREIvABwZ tbMuIrwsl2jdiAIat19TUp5ZJDnppglLwjaIhHMk6/6LxHpClif57yT57PjUpiZk/zkv pSyTFR1qrldU/Xhx53l4jNhnqdumciUBBJbpLkb23vfTYz+bFQ3bvRCY+OH305Wgfaz0 aOLJr15jT5+OCDRfGTr590K5ajveK6431n4t9Aj0ugQY6ST5IGVWyLH3iNBL0VUCwbGq pYpQ== X-Gm-Message-State: AA+aEWYEb9EzGXRQCaFJE8HWGhISsp8Q4Kn4O7Sd7y9dVKlsGCC7DqsS /01jv4fWtVDjqsHmmnw2FaX6ckuN7q9LCvZDcpc= X-Google-Smtp-Source: AFSGD/XtgIQOwS+tyPIYXQtJoD6RfQKNWnEDf1+yAFISbM7qo9conNYWodvEGdmW94vHj5Eqnk/BdTftK0LfPkLcpu8= X-Received: by 2002:ac8:5314:: with SMTP id t20mr6500102qtn.328.1543604566853; Fri, 30 Nov 2018 11:02:46 -0800 (PST) MIME-Version: 1.0 References: <65EAC6C1-4688-46B6-A575-A6C7F2C066C5@heistp.net> <86b16a95-e47d-896b-9d43-69c65c52afc7@kit.edu> <87d0qowd2e.fsf@taht.net> <20181129104332.5b2c7de7@xeon-e3> In-Reply-To: From: Dave Taht Date: Fri, 30 Nov 2018 11:02:55 -0800 Message-ID: To: Mikael Abrahamsson Cc: Stephen Hemminger , Jonathan Morton , bloat Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: Re: [Bloat] when does the CoDel part of fq_codel help in the real world? X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Nov 2018 19:02:47 -0000 On Thu, Nov 29, 2018 at 9:51 PM Mikael Abrahamsson wrote= : > > On Thu, 29 Nov 2018, Stephen Hemminger wrote: > > > The problem is that any protocol is mostly blind to the underlying > > network (and that can change). To use dave's analogy it is like being > > put in the driver seat of a vehicle blind folded. When you step on the > > gas you don't know if it is a dragster, jet fighter, or a soviet > > tractor. The only way a protocol can tell is based on the perceived > > inertia and when it runs into things... > > Actually, I've made the argument to IETF TCPM that this is not true. You > can be able to communicate earlier data from previous flows on the same > connection so that new flows can re-learn this. > > If no flow the past hour has been able to run faster than 1 megabit/s and > always PMTUD to 1460 bytes MTU outbound, then there is good chance that > the next flow will encounter the same thing. Why not use this information > when guessing how things will behave going forward? I've actually assumed that the insanely big providers actually did this, that they did a lookup on connect into BGP ASN database (aha! this address is 4G, This is DSL, This may be wifi, this one is weird). Keeping a few bits of state around awhile for every ipv4 address in the world today is trivial with today's technologies. > > -- > Mikael Abrahamsson email: swmike@swm.pp.se > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat --=20 Dave T=C3=A4ht CTO, TekLibre, LLC http://www.teklibre.com Tel: 1-831-205-9740