From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net (mout.gmx.net [212.227.15.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id 832223B29D; Sat, 24 Jun 2023 17:00:48 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.de; s=s31663417; t=1687640447; x=1688245247; i=moeller0@gmx.de; bh=wEnvBtCluwwhBQsY6bZ5on2BAqvhFCvKjHD+mcxvz24=; h=X-UI-Sender-Class:From:Subject:Date:To; b=KxDOS31FFbjaYGIOuLcUwLLlRsApRyJHKWLnKTaRqSzvelzM4iHiIzqVcRHJcNH/2fMwyk4 M81ruFX/4MQqWdeGCxyrqq/MTXhj1MZL04QygIGfJYN3OgZOqcXbeG72/XBACmoCeNTg+qZ2k C4hXM9bgFKCy3mVQPrKPXOCz0+GjDji0DbUTi3geaCda27fNtUpGSdqaWoTZSh4HBE7MHkqwc jTHJjfiGZsMW+rwHsZrl5wR/OGXRZglAipg21TISzibXDj5XD1XVcK59+LxfEd3TGlQQlzuu4 XppfHLFPYm6zN9L4+yy91cdl3aPCd+M7BRJ5JKWfqqo58hDTiScQ== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from smtpclient.apple ([77.3.0.223]) by mail.gmx.net (mrgmx004 [212.227.17.190]) with ESMTPSA (Nemesis) id 1N8GMk-1q03MF0Ge0-014B7j; Sat, 24 Jun 2023 23:00:47 +0200 From: Sebastian Moeller Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.3\)) Message-Id: <24D1A566-DFE9-4FDF-86A2-CFB30F20FCB2@gmx.de> Date: Sat, 24 Jun 2023 23:00:46 +0200 To: ECN-Sane , Cake List , Jonathan Morton via Bloat X-Mailer: Apple Mail (2.3696.120.41.1.3) X-Provags-ID: V03:K1:b6inpvYHgbLG+39gYBCd+npFrno4mP1YTEQn7FHCcjQl8RR7tey F7sv1Fpb5zWasL8S5LGMlmI6ZNiau78+eKE4sqBWhOZA/ppIlgXujjZNBnp4zjsN3p9L47m himgRp3Wz1W9SNoS1x8vcqI76gEasETRO/R5AYDfC/5maOGEjHzcse3dQxXBp6CdcwKHl5p 56WebOuw/CrOneaIGno7A== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:o6uc81kuBJc=;/16Pa7NYWOE0gwHqnKqxXjX5bjI 0VTsnI0TzAYcFpr9c3TzgosMDWaseO/acM1RF0hV41v1mr5lREZ8nKcBHH+tX7epUyHbJj+hM HpMkUIxJzFecq8pz8JUdLVxF8qXiDAyHuV5r50eUZrtIvsOb8KiUcIea62+IL5zcPog7eewIr LSl8F/uszMZiOsjEh5N82L8xyG6PoJfLdQFWOGJHR2dW9eOsh6EeRutvqZovYsXZLUVQroTyU 0I+iD7mZ4e6B1UJmZbGMowBF/L+4VG9CmvlRttnhfTPAKS2CBsJST2XcrnTNMx6neQtEQCA0M km6dTdCIQwXJKUwCsvoNRm0qdUZz+1XuUpji6GTDDpjvadT0ki7iU27yC9CjyJke9JdfaVCt0 uuT29W9krp/p+S1gJH4/fUCx7iWYZ4HDW4eMr7Lywp18G4bti6x8BrUaXmvAzNv3Lwe9jV2YY AWkyDJ8pCvhak3I16Oj5Wr4x3vSAcbcIIiZXrEB3af6q37ZaQEkVo0KjLLG7PTEJ6CVp3Gses 5g8YWNc9rdbw/P6+eQyXGOO886e1AxuRNTilxCCg6a97iE/EFReUKScJdAiSyiAEErpXL9Bwg 5zSkLxGOCK47eSWgn2LPIOkMGYR88J5K1O375TNaRll/ALefswIG7LTL2p42sWSSxDBnM1OIO YVJEG3OGgbt2nOxZfqTqeZUNAtBBeTLSav+dFdcAxdQNAopftyhWWjyFEXVA87/zAX9fcQe0P q+y9iW3u78ZkJ/z8in1WCmXLQwATTSpFFbChUqPu2Yc9P07KnMQqcRbL6yGhlSRBve2CWKV5o bfgo3N0UBvbUzjlqkcdQTh6dotYtw+2WkcyRRluHtc56hLbNrnsyrKhhbQGK9+2dhHOjaQQ8p k4AcjlgmuSBX+ayvqFu+pO3K/cFqEUpeQ9M9t4CEOvjTIClqxacWK7XXBA7tq9D4DRcyxnt9P fBjJaw== Subject: [Ecn-sane] Anybody has contacts at Dropbox? 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: Sat, 24 Jun 2023 21:00:48 -0000 Dear All, I started to look at ECN action on my homelink and I do see the expected = ECT(0) and CE marks (mostly under Linix, macos, inspite of what sysctl = seems to imply does not use ECN for me any more). BUt I also see the = following ECT(1) marked traffic roughly every 5 seconds: root@turris:/srv/persistent/captures# tcpdump -i pppoe-wan -v -n '(ip6 = and (ip6[0:2] & 0x30) >> 4 =3D=3D 1)' or '(ip and (ip[1] & 0x3)=20 =3D=3D 1)' # ECT(1) tcpdump: listening on pppoe-wan, link-type LINUX_SLL (Linux cooked v1), = capture size 262144 bytes 22:53:07.470573 IP (tos 0x1,ECT(1), ttl 47, id 42039, offset 0, flags = [DF], proto TCP (6), length 296) 162.125.21.3.443 > 77.3.0.223.51272: Flags [P.], cksum 0x0a63 = (correct), seq 2630111900:2630112144, ack 2551484650, win 130, options = [nop,nop,TS val 808373969 ecr 2543738360], length 244 22:53:08.371720 IP (tos 0x21,ECT(1), ttl 47, id 64288, offset 0, flags = [DF], proto TCP (6), length 170) 162.125.21.3.443 > 77.3.0.223.51276: Flags [P.], cksum 0x06c6 = (correct), seq 141475331:141475449, ack 2804301808, win 130, options = [nop,nop,TS val 3764736866 ecr 3088513970], length 118 22:53:22.260844 IP (tos 0x1,ECT(1), ttl 47, id 42042, offset 0, flags = [DF], proto TCP (6), length 173) 162.125.21.3.443 > 77.3.0.223.51272: Flags [P.], cksum 0xfa7c = (correct), seq 244:365, ack 415, win 130, options [nop,nop,TS val = 808388758 ecr 2543769161], length 121 22:53:28.499273 IP (tos 0x1,ECT(1), ttl 48, id 12519, offset 0, flags = [DF], proto TCP (6), length 170) 162.125.21.3.443 > 77.3.0.223.51275: Flags [P.], cksum 0xac16 = (correct), seq 2923091763:2923091881, ack 2176795132, win 130, options = [nop,nop,TS val 4027691853 ecr 2152611355], length 118 22:53:34.021366 IP (tos 0x1,ECT(1), ttl 48, id 24318, offset 0, flags = [DF], proto TCP (6), length 943) 162.125.21.2.443 > 77.3.0.223.51273: Flags [P.], cksum 0x3498 = (correct), seq 4110227536:4110228427, ack 4169408519, win 130, options = [nop,nop,TS val 561393037 ecr 811888120], length 891 22:53:38.862554 IP (tos 0x1,ECT(1), ttl 48, id 46323, offset 0, flags = [DF], proto TCP (6), length 284) 162.125.21.2.443 > 77.3.0.223.51274: Flags [P.], cksum 0x7bc6 = (correct), seq 3336805019:3336805251, ack 1852591643, win 130, options = [nop,nop,TS val 723450354 ecr 2627633601], length 232 Whois tells me 162.125.21.[2|3] belong to dropbox (I have the dropbox = client installed on that machine) So what is going on here? Is dropbox using ECT(1) for a rfc3168 style response? Is dropbox silently already using an L4S-style CC for their TCP? Is dropbox aiming for DSCP decimal 1 (aka LE) and actually setting TOS = decimal 1 instead? Was the assumption that ECT(1) is bot used simply wrong? Anyway, if anybody from Dropbox is subscribed, or anybody here has = contacts into dropbox, this seems like something worth looking into to = get it fixed? Regards Sebastian