From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) (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 B06683B29D for ; Sun, 30 May 2021 05:22:35 -0400 (EDT) Received: by mail-wr1-x436.google.com with SMTP id l2so233659wrw.6 for ; Sun, 30 May 2021 02:22:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heistp.net; s=google; h=message-id:subject:from:to:date:user-agent:mime-version :content-transfer-encoding; bh=JAQj0c7p9PjgmeSNmuyCTtrFOTs2Kohxv/ebMBhGblI=; b=FSawJsrrlpGJjswnDUzklkxOQ+IZMB3K+cf+y7gAM7RftxB9z80zvLwRy4G9TceYuV sksYmVKZGIo1haAl2G4EL9pa1vvrGiYagRgMmVgpK1K7VsX1WCmkM6cG2djAu4IsqQC6 ZsjTMiuLe33X35xQK5PLaLjENHcpJB57Fwo/UfapEsDpaeNOtJqsR2rET/a1lD1aEnXY 8Ckhp0y4DX/syTxZ73S6aO/kTU5qJSUaFpSboI5toZ3QtO/okW634q1x/98HhnRxSyoI ms33q25uNSneCGXIhJwi0+38w1Y513aFVKeV/emaElSGduP7zVT+HX8PjNODdJXJeRzy DWlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:date:user-agent :mime-version:content-transfer-encoding; bh=JAQj0c7p9PjgmeSNmuyCTtrFOTs2Kohxv/ebMBhGblI=; b=gLk1X1cIxlMy9lftHscWxlMUdygXVI9qoEOGFh6NI/Np/Phu9BLQ4cMzLpQ0W15S2K s7+wubTa4koMmuq1ClHPEL+KJWzeR1T0W2JuRIjC0NrRc4i0ocQAO3OGQGbaC+nBvVwk vxHCVYGwZIx1WXc/qVkLokpDwTduZqYsHmrnycD6XGAqU8LucHBo2REau6rXbEor8gqa j3EhA7irZ7gzuC+VTS2NBxke1kE6h33VoKK+C0Pvqyq7lXieEC8VeadmsjZMpHkgqTYq ZnvpR7Wid4bpNeLEhL17J2JkixrXRolpWOauogJVouVrl0ShQorpa+GWOqJl9sPcrQge QdtQ== X-Gm-Message-State: AOAM533QHVnScaogiqcO1EXF8rS90Cv8Bbq9H2ScKQq1DRRgz9sCcsQa m6lb9hOgO4zZiXzpGOV0qlLNVnVVVPgCfw== X-Google-Smtp-Source: ABdhPJzZOolMmEHYRFEc44VmRvK7/pI5clMm41GCqadB0FKWc+4MfSmC+Lcy4af4tu/qtdg3dRA6iQ== X-Received: by 2002:a05:6000:12cc:: with SMTP id l12mr16683783wrx.91.1622366554422; Sun, 30 May 2021 02:22:34 -0700 (PDT) Received: from sova.luk.heistp.net (h-1169.lbcfree.net. [185.193.85.130]) by smtp.gmail.com with ESMTPSA id d17sm5702422wrg.26.2021.05.30.02.22.33 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 30 May 2021 02:22:34 -0700 (PDT) Message-ID: From: Pete Heist To: ECN-Sane Date: Sun, 30 May 2021 11:22:33 +0200 Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.40.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Ecn-sane] ECN on Android and webOS 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: Sun, 30 May 2021 09:22:35 -0000 Yesterday, I observed CE marks and ECE flags in a production environment with an OM2P-HS WiFi AP (has the ath9k driver with the airtime fairness changes signaling with ECN). This is the first time I got a chance to look at this with WiFi in the wild. There were two notable devices sending ECEs while streaming content: 1) DHCP client ID: "Galaxy-S21-Ultra-5G" This is presumably a Samsung of that model, which was released earlier this year and ships with Android 11. 2) DHCP client ID: "LGwebOSTV" This apparently runs webOS, a Linux based smart TV OS that doesn't seem to be based on Android. Does anyone have confirmation that either Samsung or LG has enabled ECN in some of their recent devices? If you want to watch for CE marks or ECE flags, this worked for me: tcpdump -ev -i -n \ '(ip and (ip[1]&0x03 == 0x03))' or \ '(tcp and (tcp[13] & tcp-syn == 0) and (tcp[13] & 0x40 != 0))' It's also possible to watch for CWR (tcp[13] & 0x80). My vantage point was upstream from the AP, where I usually saw no CE marks (except occasional ones from WAN ingress), but I'd see ECE in response, with the WiFi AP being the main apparent source of CE. Pete