From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-x235.google.com (mail-lj1-x235.google.com [IPv6:2a00:1450:4864:20::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 9C21A3B2A4 for ; Mon, 27 Jul 2020 18:46:22 -0400 (EDT) Received: by mail-lj1-x235.google.com with SMTP id h19so19015915ljg.13 for ; Mon, 27 Jul 2020 15:46:22 -0700 (PDT) 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=BY8kTuIsINj1AHRCDsVULphepw9ErUikeFex/wTlYvs=; b=aYOIjpWGciPA1KIxbmG4bkJjG7n0X8VzFo+LTI7wv2lIONn4Tlczo66BP+apUnQds4 BBSn2WVjoy3biepmfrrKczsEG8mN9mGJmeATDT62gQncJgjcVueFc6piFBCTFJVElF9O 02croSlngZlekm2RXLePjaSeFZ/d5RAOF4YE2Lo08oiqWMTs3MKkY1bU4IdrS9sI88PK cDKADSi7ceJN7S9X5OS75QRJyRIfBeYfPPCIcX+Hqmdjd1GhW57oMP4uGv+Z8s9YcxhH K9ht1fhOo6eLsq4DWJa1ne0Dyg0uhMsqBjenJZljrHMujx+t7gFH37xByrpoNEwerf3n fIqQ== 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=BY8kTuIsINj1AHRCDsVULphepw9ErUikeFex/wTlYvs=; b=nnsbZXq0Dx26820Z7sMSgVT5nfAoCcd+qb5gT/v4uVeqYPIcvG+7THs0uuzzhJ5vNG f0gEGxfDjCtFO/vPwa1t/B7r7TMOf+u7NzdnHqm3c68MDFvKPkjJrQXp+v6DNBx51fUa g9tvuLkHdkIvy0rIOlkIHYilCeeF9agPrSDoHx/KWjMyxsDdS24JfmQbA/uulBwaDUx7 gtLUKKVKmxt+a+0M943c7/3MwACWLAeZuR78JEFJ6TWiRKOgjIOlWyeEax+drhxLE8qJ 3V+8fyIUccnnCjlF5JX1I+GVKY8dfonq9wZPzYHBV/Xboj3qsPDR79IZ0TB5aCf5U6hW fXYQ== X-Gm-Message-State: AOAM532Ld/amxTu9eYi9N0jUvfY/IDpB3qH2MJK34HwAnLvVNie6uo+t 2tPJ5G9NNe9NswjWDzDW6kw= X-Google-Smtp-Source: ABdhPJw521Z4yrCa6Dt/Pzm0/ASBJA/xdf/2km+HULt1zXFtx6ZES0V/qRU7wjnXJ5SMywATifGrnw== X-Received: by 2002:a2e:92d0:: with SMTP id k16mr11433638ljh.48.1595889981525; Mon, 27 Jul 2020 15:46:21 -0700 (PDT) Received: from jonathartonsmbp.lan (83-245-252-162-nat-p.elisa-mobile.fi. [83.245.252.162]) by smtp.gmail.com with ESMTPSA id b11sm3328944lfb.42.2020.07.27.15.46.20 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Jul 2020 15:46:20 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.6\)) From: Jonathan Morton In-Reply-To: Date: Tue, 28 Jul 2020 01:46:03 +0300 Cc: cake@lists.bufferbloat.net Content-Transfer-Encoding: quoted-printable Message-Id: <6B18F76E-A466-42A7-ACF7-52D5E6CD3572@gmail.com> References: To: Jim Geo X-Mailer: Apple Mail (2.3445.9.6) Subject: Re: [Cake] Cake, low speed ADSL & fwmark 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, 27 Jul 2020 22:46:22 -0000 > On 28 Jul, 2020, at 12:41 am, Jim Geo wrote: >=20 > Thank you for all the efforts you have done to make internet usable. >=20 > I currently use htb & fq_codel in my low speed ADSL 6Mbps downlink/1 = Mbps uplink. I use fwmark to control both uplink and downlink with good = results in terms of bandwidth allocation. Streaming video is chopping = bulk traffic successfully. >=20 > Is setting up cake worth the effort at such low speeds? Would it = reduce latency? Cake has a better-quality shaper than HTB does, and a more sophisticated = flow-isolation scheme than fq_codel does. These tend to matter more at = low speeds, not less. It's also generally easier to set up than a = compound qdisc scheme. > Regarding fwmark can you please elaborate more on the calculations = performed? Man page is not that helpful. >=20 > My understanding is this: >=20 > I use 1,2,3,4 as marks of traffic. > If I set the mask to 0xffffff[..] the marks will remain unchanged. = Then right shifting will occur for the unset bits, so they will land on = tins > 1,1,3,1 >=20 > Can you please correct me? If logical and performed between mask and = mark value? Since there's only a few "tins" at a time used in Cake, and the fwmark = is a direct mapping into those tins, a narrow mask is probably safer to = use than a wide one. The reason for the mask is so you can encode = several values into different parts of the mark value. The shift is = simply to move the field covered by the mask to the low end of the word, = so that it is useful to Cake. For your use case, a mask of 0xF will be completely sufficient. It = would allow you to specify mark values of 1-15, to map directly in the = first 15 tins used by Cake, or a mark value of 0 to fall back to Cake's = default Diffserv handling. None of Cake's tin setups use more than 8 = tins, and most use fewer. - Jonathan Morton