From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-x32e.google.com (mail-wm1-x32e.google.com [IPv6:2a00:1450:4864:20::32e]) (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 9764B3B2A4 for ; Tue, 22 Dec 2020 15:07:45 -0500 (EST) Received: by mail-wm1-x32e.google.com with SMTP id q75so3355710wme.2 for ; Tue, 22 Dec 2020 12:07:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:from:autocrypt:subject:message-id:date:user-agent:mime-version :content-transfer-encoding; bh=3Bg0AdMH2Bxj9wc5p93CGyaRESmDGUFIbb7EW8rl5l8=; b=lJr9sbqeebQyVcdbI0SzYxvvevmzBdoSlL7IkFnVhgfVI3c+yBVj9GHokikVREGXtZ jSz4zCql8FK15vOOZPop5PJc8agUz/Xjr+CB4GOmO5mwJvIEoZ0ByGxUTIKzHIm2/hhJ msdhjAUnKRCNkU8+YU86bnnXY4KAU1BC8x6ZSryeVJG6X0tTta88v/4iq7qyp4/Kd/WQ N1sNfoQepa4eVLrLWO5uk/8ozRqL/7wDn1rHpb2ICmRZ0Rrj9Q9jbeCSgnV5OWwK4XCQ YyYHWNjN5KrvUBP5v8837wsvIMLI6o5vdoIAF5i67lng+SpC7vWirWD3FatVGDLmExh7 qKFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:from:autocrypt:subject:message-id:date :user-agent:mime-version:content-transfer-encoding; bh=3Bg0AdMH2Bxj9wc5p93CGyaRESmDGUFIbb7EW8rl5l8=; b=YNWeq4QaySAcg7TSrG1W9A6uBTzU5X5j21JErF1ohNv6CxL0n/AwS8oNDm7YeXnlFo A6IukU/2ryDoFaCieh/rtPfEAct71Xw5MkVGuZnkfT9Th98pGzQVNdwasq6YWZFte1iB 6ykfM6Eq98geL0tQjD9S5MxUl29m7+fc6ZxVyOBiiClbYhiyNKf9t0WzWw4L1Qm8rvxr WNfUGZmuFJMB50yclumFB0YwfCTzMKWLfytoSJGi2cWKpoOxf8bsBmjXXCkIvnYDICPD tA4LYs53Fg+Nc7Iapaxt/vi1AkeegJkKMf9C54xwnAxLgB9Gz0k0iNJop2PyLdQZy++n qJNw== X-Gm-Message-State: AOAM532UqaZU7d0Ngt4hByXX4MXUGmrfxCB9rqjjU0OrYuIAvsuUkwuK N/tkWBxwInxEK5MSKjhzf27RWxDHuhw= X-Google-Smtp-Source: ABdhPJxqd6an/xTjErjYwOK/cCYgkaCwsix/JJ9HeWIcyYO9M228YYrIKBVtfE+oUD7/EI7RxCKH6w== X-Received: by 2002:a05:600c:250:: with SMTP id 16mr7276699wmj.6.1608667664638; Tue, 22 Dec 2020 12:07:44 -0800 (PST) Received: from [192.168.1.116] (cpe90-146-174-71.liwest.at. [90.146.174.71]) by smtp.gmail.com with ESMTPSA id h83sm30310114wmf.9.2020.12.22.12.07.44 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 22 Dec 2020 12:07:44 -0800 (PST) To: cake@lists.bufferbloat.net From: xnor Autocrypt: addr=xnoreq@gmail.com; keydata= xjMEX8GJihYJKwYBBAHaRw8BAQdAhiXbV9uWXaRTLr0gtbgOSXKiajCO+q+GZ/Lanh1SeafN F3hub3IgPHhub3JlcUBnbWFpbC5jb20+wpEEExYIADkWIQSIwFsdmuvVRn8KTpQPFnChazvz EAUCX8GJigUJAeEzgAIbAwULCQgHAgYVCAkKCwIFFgIDAQAACgkQDxZwoWs78xAqlgEAlzmt RBZWsvAir0IcwvcgSZOCKzt8onO8yoMi7qq/3M4A+wWj3lX9lx0WEBZtPEJCw+WZ7+w7c6wz 4//han+cxsIEzjgEX8GJihIKKwYBBAGXVQEFAQEHQCRV3YyeTk35SbVbzBMDTPIc4L+Nuhkh tOIU4ZlXy3QoAwEIB8J+BBgWCAAmFiEEiMBbHZrr1UZ/Ck6UDxZwoWs78xAFAl/BiYoFCQHh M4ACGwwACgkQDxZwoWs78xBjpAD+LZuOaaaPgqJx/u/PxUviEjFr76XwFiwnXFSUQP9RcpIB AJEpdVrCl6fNm+QrUcjfAe7VN1IrCgeEpNA6fmz5kXEK Message-ID: <421ffd89-0c2c-1187-380c-03a0968f4095@gmail.com> Date: Tue, 22 Dec 2020 21:06:32 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: [Cake] ECN not working? 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: Tue, 22 Dec 2020 20:07:45 -0000 Hello, after observing mostly drops in cake (instead of marks) I did a little te= st: Client is a Linux 5.9.13, server is the same. Kernel ECN parameters are set identically for both client and server to: net.ipv4.tcp_ecn =3D 1 net.ipv4.tcp_ecn_fallback =3D 1 Using tcpdump on the server I see the following: The client initiates the IPv4 TCP connection with: IP Differentiated Services Field: 0x02 (DSCP: CS0, ECN: ECT(0)) TCP Flags: 0x0c2 (SYN, ECN, CWR) Seq=3D0 Win=3D64240 Len=3D0 MSS=3D1460 WS=3D256 SACK_PERM=3D1 The server responds: Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT) Flags: 0x012 (SYN, ACK) Seq=3D0 Ack=3D1 Win=3D64240 Len=3D0 MSS=3D1460 SACK_PERM=3D1 WS=3D128 Shouldn't the server respond with ECT set in the SYN ACK packet and possibly also have ECN-related flags set in the TCP header?