From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mail.toke.dk; spf=pass smtp.mailfrom=lang.hm; dkim=fail; arc=none (Message is not ARC signed); dmarc=none Received: from mail.lang.hm (wsip-70-167-213-146.ph.ph.cox.net [70.167.213.146]) by mail.toke.dk (Postfix) with ESMTPS id 8A80D70F65F for ; Tue, 30 Sep 2025 14:37:26 +0200 (CEST) Received: from [10.2.2.53] (unknown [10.2.2.53]) by mail.lang.hm (Postfix) with ESMTP id 0ED6120AAB8; Tue, 30 Sep 2025 05:37:24 -0700 (PDT) Date: Tue, 30 Sep 2025 05:37:19 -0700 (PDT) From: David Lang To: Jonathan Morton cc: david@lang.hm, cake@lists.bufferbloat.net In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Message-ID-Hash: 6APDZ3XNZK7SMHPF3Q2K34WRVBELVOSU X-Message-ID-Hash: 6APDZ3XNZK7SMHPF3Q2K34WRVBELVOSU X-MailFrom: david@lang.hm X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list Subject: [Cake] Re: help request for cake on a large network List-Id: Cake - FQ_codel the next generation Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Jonathan Morton wrote: > On Sunday, 28 September 2025, David Lang wrote: >> I'm starting to prepare for the next Scale conference and we are switching from >> Juniper routers to Linux routers. This gives me the ability to implement cake. >> >> One problem we have is classes that tell everyone 'go download this' that >> trigger hundreds of people to hammer the network at the same time (this is both >> a wifi and a network bandwidth issue, wifi is being worked on) >> >> The network is pretty flat, a couple of subnets each on ipv4 and ipv6. >> >> Any suggestions on how to configure cake for this sort of environment where >> there are so many devices? > > So far as Cake is concerned, the normal setup should work fine even under > stress conditions. If there are too many simultaneous flows to achieve full > flow isolation, it degrades gracefully to statistical multiplexing, and you > still have the AQM working to keep everything responsive. Or rather, a > thousand AQMs working in parallel... what would need to be done to increase resources to allow for full isolation of more flows? > Of course, this only matters when Cake is set up to be the bottleneck. If > wifi is the bottleneck, you'll want a wifi stack with integrated fq_codel, > which I believe still applies to only some hardware since it needs to manage > the MAC queue which some devices don't expose. This has the extra smarts > needed to adapt gracefully to wifi's foibles, and might already be enough to > convert an effectively nonfunctional wifi into one that feels, if not fast, > then at least reliable. I am doing everything I can to eliminate wifi as the bottleneck and overload our uplink ;-p mostly the wifi bottleneck is being eliminated by having lots of separate APs for people to connect to. David Lang