From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x231.google.com (mail-lj1-x231.google.com [IPv6:2a00:1450:4864:20::231]) (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 7CF7F3BA8E for ; Sun, 9 Dec 2018 08:21:30 -0500 (EST) Received: by mail-lj1-x231.google.com with SMTP id k19-v6so7220460lji.11 for ; Sun, 09 Dec 2018 05:21:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=VJgiu2EMQRanKGhcoX2SVMSghsPd2sNp1JYhXH1QeTw=; b=UY+6xRT4I9SJlDjz9oRFwQyyXcRPYVsKWkiQKaPfI7f/75NmsOxgkgKGujH/oaHjY2 tq1txc+S73cn38dOTd4AAmeJArBFi+DWZqT9fT/DedtxHEzWF/NojDmc8/qYfP4niXow ZPHwuKsHUgSH6qcSdIR8fMnf5AS8SyZ3c0FDZfKEljTV4yuW8zhrFfvJ6DWE9BUoEhsw XgRSWNp5K0Iq4hRyS7A7vzlCtHVfFXyfEUQBj5Ab3SFXJVcdf38SSFmhhzIse83Z5glv uL62G0Gzo8/sYnj/QawIvpQJTJ1DjTPdK1/FObDb/x/1hQLEV8g2n/Q0vZXsNobbda/p bVog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=VJgiu2EMQRanKGhcoX2SVMSghsPd2sNp1JYhXH1QeTw=; b=cJoDPHSG4Hw4hMIRmhUxbxA6aOJQd1P/+5SBtiZUUdw3ueEv4AAdup1DhZzmj/HEV3 js+XHkDLPS5miSDhHLr9qxwTnVGLVefwj5o22zXYOliWDWA9i75v1Ff2e2me3X1U5uM7 H6HyzGRQoDoMs3KM2c8jotX5W9j/IfIfLynVg8QvEqZfexmY/6tWe5QQPuV8Y7z6ZjrB zDActuX4rWvk7kZuWPhl9uNVg0ljw+mDhxlhKEy7tre2KFCuXTARsFwxKm12h5j1Ndpw Xl2CalOqU5zSvZwvkrJhhpjUJLJ3Aw0bV1ZsybrTC9REi+012zdOCIYfNcgR+SLwoxzw 26EA== X-Gm-Message-State: AA+aEWZT2f+Q4sTRpWngj3DoNThpIwXLbd8zdRV4PiSR83AwDWy3rE/6 iBxgF2c4cx7vhpBsR13Xjls= X-Google-Smtp-Source: AFSGD/VMeCUscZ68gIhjZKdAc/WJNOq4vhLjhazjYMzqcv35Nj59zPO3C5Hs0mzDk49/eYzsW5n7ow== X-Received: by 2002:a2e:890b:: with SMTP id d11-v6mr4999385lji.113.1544361689295; Sun, 09 Dec 2018 05:21:29 -0800 (PST) Received: from jonathartonsmbp.lan (83-245-234-248-nat-p.elisa-mobile.fi. [83.245.234.248]) by smtp.gmail.com with ESMTPSA id u65sm1658385lff.54.2018.12.09.05.21.28 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 09 Dec 2018 05:21:28 -0800 (PST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) From: Jonathan Morton In-Reply-To: Date: Sun, 9 Dec 2018 15:21:26 +0200 Cc: Dave Taht , dave@taht.net, cake@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <8467184E-7C35-4AFE-9CC6-292215022FDB@gmail.com> References: <87va4nzsn4.fsf@taht.net> <6578A0D1-FF6A-474E-A6D5-98185F98CB45@gmail.com> <08381337-F99A-46D1-87AF-B0F71A8753BC@gmail.com> <949D58FF-9C2F-4516-8547-20A712EC0C92@gmail.com> <271B3584-068F-4FED-B037-B8E920A9EE55@gmail.com> <70BDD881-B509-43FE-81BB-E9C4B1145FA1@gmail.com> To: Jendaipou Palmei X-Mailer: Apple Mail (2.3445.9.1) Subject: Re: [Cake] COBALT implementation in ns-3 with results under different traffic scenarios 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: Sun, 09 Dec 2018 13:21:30 -0000 > On 9 Dec, 2018, at 10:37 am, Jendaipou Palmei = wrote: >=20 > By hidden queues, do you mean the NIC buffers? ns-3 has a Linux-like = traffic control wherein the packets dequeued by a queue discipline are = enqueued into NIC buffer. That's right. Linux now uses BQL, which (given compatible NIC drivers) = limits the number of packets in the NIC buffers to a very small value - = much smaller than is evident from your data. If you were to measure the = end-to-end RTT of each, I'm certain you would see this effect dominating = the mere 50ms latency you're trying to model. Ideally, AQM would applied to the hardware queue anyway. For simulation = purposes, I recommend reducing the NIC buffer on the bottleneck = interface to 1 packet, so that the simulated AQM's effects are easiest = to measure. - Jonathan Morton