From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-xd32.google.com (mail-io1-xd32.google.com [IPv6:2607:f8b0:4864:20::d32]) (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 BA3CC3B29E for ; Tue, 30 Jul 2019 12:38:07 -0400 (EDT) Received: by mail-io1-xd32.google.com with SMTP id s7so129443589iob.11 for ; Tue, 30 Jul 2019 09:38:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to :content-transfer-encoding; bh=xs6XGH9TTMx0D8oi+nTF/VON9jyplzrxhlkaKsHPVnU=; b=O8Qbc+EjHgtScKLMo80Ggnv1IQ2bL+LeDNO9Lz4/gCjUY3AkZxGkfElhB0ssS+dw3C YEVqKhA49u0IybCBK79vtnmvbGaVIBj9nbCV2Q8odlR32uwJ02gfIHQqeBMZXSu2y2j8 b/GwXEvNiAIscitXWLtZi1aQvPOrgMb++zpppAeKx0O/+SamxlPKKH5toEYcGgO+qYTH Pp0dvjp8wQsXmW7B27gCGq0pFzg8w5SRlllEenGvXYzr7OsfmMnLSijTCgyKNI+UC0Mm ls6qSVu2RVhwyh1EQcmOuxywwLG3gaZL3bttIEcYrG+Nr9UEw2g7SO8SSgIIx6RN78Wu L/mA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to :content-transfer-encoding; bh=xs6XGH9TTMx0D8oi+nTF/VON9jyplzrxhlkaKsHPVnU=; b=DxsqcX/A6cnAsnShql4bG5SzDmdIxhejhSYCMlom9gSq25tDNfr/teJKAjzv9EW0Zn Hx4oef90feacRA3nW9bxc1wvZ1Iq1rGZ0yRZDut+2qTQlip3pArQlpa/jhvoAdNx+Tfc K4JtdMfTN7cAQVJhDNFz1DFbrQEYEqvxiSLaeAWgTJlpQr2IoZMjhjWVehhgIJ95jNoA 0vZapXrDPZfgP6a6ZoZnLLJIipF+Q0VkiGdIC/Y3aN6nCN61rGxLAfXk/V89xldJArS/ rLR8OJNS/9DOvtP1r0/VCkyhzt2vcwFHGvEtMF/xCGQfWKdER9YitavQK9uCP8kvbsex fWYQ== X-Gm-Message-State: APjAAAVvM4E/DxGi49VfVnCqboOn9EREbMohXghQQwQfYmJUwBs+tRYc H2FWXLgJ39gc8PMPDeONwk6/JMyqHcUzUw8MfrL3dhsa X-Google-Smtp-Source: APXvYqyJW81LhXj3uH1WAlt96QgIRMTL0zzkeRXAvrUYMJ9vJ4YSk9XtnMJ/pnhairqcQveu0cqvqERcGXW6q5gu9Vc= X-Received: by 2002:a5e:d615:: with SMTP id w21mr40043522iom.0.1564504686933; Tue, 30 Jul 2019 09:38:06 -0700 (PDT) MIME-Version: 1.0 From: Dave Taht Date: Tue, 30 Jul 2019 09:38:01 -0700 Message-ID: To: ECN-Sane Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Subject: [Ecn-sane] tsvwg preso for sce is up X-BeenThere: ecn-sane@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion of explicit congestion notification's impact on the Internet List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Jul 2019 16:38:07 -0000 SCE: https://www.youtube.com/watch?v=3DFDK88vdE5r0&t=3D1h15m A couple notes: at 1:25:20 - mirja had asked what the sce marking threshold was, not the codel parameters (I think). I think she wanted to know the sce_threshold? At 1:27, I'd really love the flent files to be able to zoom in on that data, It's unclear how low the ping overhead is. A 100Mbit result using native ethernet and bql at the bottleneck instead of cake with a rate limit might be interesting. Gbit also.... (have 10gbit in my lab) 1:27:49 Gorry said "This looks like FQ", and no, it's the real convergence of two SCE AQMed flows at 50mbit, 80ms rtt as Jonathan pointed out, which takes 45 seconds. And that brought to mind, what is your intuition? What would you expect for convergence using fq? And what is it? 1:31:18 One thing long since vanished from the l4s debate is that codel achieves a ~5ms queue depth, where pie only gets 16ms. The need for "ultra-low-latency" is less when you get that kind of result in most cases from your aqm. I've always felt that pie could be improved - the principal flaws being the rate estimator - and the update interval. fq-pie on bsd borrows codel's rate estimator. But I digress. Flent has a default sample rate of 200ms, which means that it can miss some details. You can sample instead at rates as low as 20ms, although this is murder on your local cpu and can heisenbug the tests. It's generally a good idea to be sampling at double the rate you care about (nyquist theorim), so a 40ms sample rate here would have shown more detail. If you really, really want more detail than that, packet captures are a way to go. Got any? --=20 Dave T=C3=A4ht CTO, TekLibre, LLC http://www.teklibre.com Tel: 1-831-205-9740