From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gateway36.websitewelcome.com (gateway36.websitewelcome.com [50.116.127.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id D8B3E3CB35 for ; Mon, 10 Aug 2020 12:04:09 -0400 (EDT) Received: from cm14.websitewelcome.com (cm14.websitewelcome.com [100.42.49.7]) by gateway36.websitewelcome.com (Postfix) with ESMTP id 99023400E448F for ; Mon, 10 Aug 2020 10:28:12 -0500 (CDT) Received: from box5867.bluehost.com ([162.241.24.113]) by cmsmtp with SMTP id 5AHPkHTLmBD8b5AHPkr1nk; Mon, 10 Aug 2020 11:04:07 -0500 X-Authority-Reason: nr=8 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tomh.org; s=default; h=Content-Transfer-Encoding:Content-Type:In-Reply-To:MIME-Version :Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=aHAksK45cVZ3WsIp/GLJdIPD9FoZrwOGsTwO16L2V40=; b=dkHs99aZCGVazKZlRZSMJSvuDU nq7y1g1bOUmTz095A1H4IaVM8LAxn+g8oiqQt9ymijke+H201N1oB9w5nzXx1WBHAIs69oUJzgwnu Fis8DBhWDtr5x6SnWFkb6aiHsv6UCgogCHa2FuCuAwLFlAe0V9Ni26pfcinf9dKrf280RZhW9ng7q xe/SsNC7yshEo7a+0eABld39Z7XpLtwd3FOGgn5lrL3VZYiO2SZNsrv/iERlRTLyMiHJ8wSdwq74F c28ISmFZ/MRlgVd5BBK6qRlE+HXo5mmKMkD+oqMBESZLWvpqC1rCuEmYDa+0tUPvODtTetOxh9XxD VZwNUyVA==; Received: from c-73-19-103-93.hsd1.wa.comcast.net ([73.19.103.93]:37576 helo=[192.168.168.110]) by box5867.bluehost.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1k5AHO-003cSd-Nb; Mon, 10 Aug 2020 10:04:06 -0600 To: Jonathan Morton , moeller0@gmx.de Cc: sterling.daniel@gmail.com, davecb@spamcop.net, dave.collier-brown@indexexchange.com, bloat@lists.bufferbloat.net References: <225a9c89-ac76-f21e-1450-5deeb3cd23eb@tomh.org> <04949cee-c4de-900c-e1b1-4b1f227933eb@rogers.com> <87878C8E-88D6-4218-A3D9-1CAE99CB1B59@gmx.de> From: Tom Henderson Message-ID: <1e993b75-46b9-8329-eaaf-dc33afdcebe0@tomh.org> Date: Mon, 10 Aug 2020 09:04:05 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - box5867.bluehost.com X-AntiAbuse: Original Domain - lists.bufferbloat.net X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tomh.org X-BWhitelist: no X-Source-IP: 73.19.103.93 X-Source-L: No X-Exim-ID: 1k5AHO-003cSd-Nb X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: c-73-19-103-93.hsd1.wa.comcast.net ([192.168.168.110]) [73.19.103.93]:37576 X-Source-Auth: tomhorg X-Email-Count: 6 X-Source-Cap: dG9taG9yZzt0b21ob3JnO2JveDU4NjcuYmx1ZWhvc3QuY29t X-Local-Domain: yes Subject: Re: [Bloat] How about a topical LWN article on demonstrating the real-world goodness of CAKE? 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: Mon, 10 Aug 2020 16:04:10 -0000 On 8/10/20 8:57 AM, Jonathan Morton wrote: >> The current best practice seems to be to instantiate cake/SQM on a reasonably fixed rate wan link and select WiFi cards/socs that offer decent airtime fairness. >> Works pretty well in practice... > Yes, AQL does essentially the right thing here, again along the lines of limiting the influence of one machine's load on another's performance, and completely automatically since it has faurly direct information and control over the relevant hardware. Cake is designed to deal with wired links where the capacity doesn't change much, but the true bottleneck is typically not at the device exerting control. > > On that note, there is a common wrinkle whereby the bottleneck may shift between the private last mile link and some shared backhaul in the ISP at different times of day and/or days of week. Locally I've seen it vary between 20M (small hours, weekday) and 1Mbps (weekend evening). When Cake is configured for one case but the situation is different, the results are obviously suboptimal. I'm actually now trying a different ISP to see if they do better in the evenings. > > Evenroute's product includes automatic detection of and scheduling for this case, assuming that it follows a consistent pattern over a weekly period. Once set up, it is essentially a cronjob adjusting Cake's parameters dynamically, so providing a manual setup for the general OpenWRT community should be feasible. On “tc qdisc change”, Cake usually doesn't drop any packets, so parameters can be changed frequently if you have a reason for it. Thanks for your insights, they have been helpful.  I also just found these references: http://flent-newark.bufferbloat.net/~d/Airtime%20based%20queue%20limit%20for%20FQ_CoDel%20in%20wireless%20interface.pdf https://blog.tohojo.dk/slides/llc19-linux-wifi-bloat.pdf - Tom