From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f171.google.com (mail-ob0-f171.google.com [209.85.214.171]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id 66CE2200B49 for ; Sun, 5 Aug 2012 11:14:34 -0700 (PDT) Received: by obqv19 with SMTP id v19so11002924obq.16 for ; Sun, 05 Aug 2012 11:14:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:x-system-of-record; bh=MfRnIhGfzyx9VM4B8Gjnj6vqco6uSQyAZBThGLCKNVU=; b=oIwzMRCEa81yoApJdm93OFzWYwiXXvVPZeImW/yUpIJo5t23tJvUDagvIkdq0WWqdB CH5irupbVF+QHQeq8m0pSvliaqD8GVaZ6mPstxCto4ARoWyAPOAEFhI8/OI8dxOkTQUG 5/yMMJD6EYGKtXj0D+fteX54Q37hXNGc9Btb/i8lafhKMSZ1x0OT4c7DrNPtLY2K7BK3 V1lw/DRw7LcbgBgtzk4mH9E+u29Z38feV+BBiEKM7Eeg+09vjGpczGdvvFcVpKCz4vU/ yuLg3CrFRPvHI3SYQc35jEjZA47bihGb0lol35Cq0uGhScB7WrtwLl9py21RC8Zz7Wb4 o8NA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:x-system-of-record:x-gm-message-state; bh=MfRnIhGfzyx9VM4B8Gjnj6vqco6uSQyAZBThGLCKNVU=; b=HqE3swz/4kwz7XUY1ayAljlM5ugGBEIWjO3DcutnO8cxEfdBFL0W3ZISdEEQl3YMmD ZZi9h9zHF5CHWCgqxVDFuhREmyy5HW2Ka6m6eIb6RaxOr4OZFLOjtp4KH4lJXjQht0q6 ogQj6Mt20SNhQdxATNOgcPhHfHO5xGIQ8/c+NDnufSEgxNFGH0ewdT9/seS0XnWdHhXE bplf3qo7oUf/WoSHi1+DYlU+zV3rBYRIPNIYROqdSQlIhG/0k5N4ILMFQxvOR4wcdqUF UD1IW9mSmxPFemhTExaiWcKwKBmoUZVBCCZss+SXXWvlgmbyb6iH2fZK0M4v/mtNiNxq dR6w== Received: by 10.182.192.41 with SMTP id hd9mr15709300obc.17.1344190473080; Sun, 05 Aug 2012 11:14:33 -0700 (PDT) Received: by 10.182.192.41 with SMTP id hd9mr15709290obc.17.1344190472768; Sun, 05 Aug 2012 11:14:32 -0700 (PDT) MIME-Version: 1.0 Received: by 10.60.99.37 with HTTP; Sun, 5 Aug 2012 11:14:12 -0700 (PDT) In-Reply-To: <1344188112.9299.1614.camel@edumazet-glaptop> References: <1344048299-26267-1-git-send-email-dave.taht@bufferbloat.net> <1344062738.9299.1453.camel@edumazet-glaptop> <501D99C4.20902@pollere.com> <7EB59257-1A8E-4567-8AD3-5016594565CC@gmail.com> <1344144623.9299.1557.camel@edumazet-glaptop> <4A256974B5054317913BC067C4E5FAE1@srichardlxp2> <1344187557.9299.1610.camel@edumazet-glaptop> <1344188112.9299.1614.camel@edumazet-glaptop> From: Yuchung Cheng Date: Sun, 5 Aug 2012 11:14:12 -0700 Message-ID: To: Eric Dumazet Content-Type: text/plain; charset=ISO-8859-1 X-System-Of-Record: true X-Gm-Message-State: ALoCoQm5aTJwp7v/1ioN3ADZtK1yiCyWgo4Mh1B9QFzCQN6fzcNhMEpYCVsdc/avoaU65VTvg9d2+DzxnFdt1O4uUkPN/65GbOH0FECe5YML5ByfAh2WrAwt65R/hF0yGYlgUFrh0hdx2y1aMUHd9HwfLr/vKKr6mWRsMQwrqzVd9UN0YfuUaURZMeyYQGlwv39nCHGVvyfe+37rSQjxL4AXdVd/8ZdG+A== Cc: codel@lists.bufferbloat.net Subject: Re: [Codel] [RFC PATCH] codel: ecn mark at target X-BeenThere: codel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: CoDel AQM discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 05 Aug 2012 18:14:34 -0000 On Sun, Aug 5, 2012 at 10:35 AM, Eric Dumazet wrote: > On Sun, 2012-08-05 at 19:26 +0200, Eric Dumazet wrote: > >> It could be a flaw in linux implementation, I admit we had so many bugs >> that it could very well be still buggy. > > And at first glance, the following tcpdump seems suspect : We can see > all ACK are delayed by about 40 ms but RFC 3168 (sec 6.1.3) does not mandate immediate ACKs for ECE marked ones? is this because ECN response is per round-trip? > > 19:30:54.367739 IP (tos 0x3,CE, ttl 64, id 52620, offset 0, flags [DF], proto TCP (6), length 1500) > 172.30.42.19.50341 > 172.30.42.18.50103: Flags [.], seq 156841:158289, ack 1, win 115, options [nop,nop,TS val 3115533 ecr 111212487], length 1448 > 19:30:54.406063 IP (tos 0x0, ttl 64, id 62099, offset 0, flags [DF], proto TCP (6), length 52) > 172.30.42.18.50103 > 172.30.42.19.50341: Flags [.E], cksum 0xac88 (incorrect -> 0xe2b7), ack 158289, win 551, options [nop,nop,TS val 111212491 ecr 3115533], length 0 > > 19:30:54.407212 IP (tos 0x3,CE, ttl 64, id 52621, offset 0, flags [DF], proto TCP (6), length 1500) > 172.30.42.19.50341 > 172.30.42.18.50103: Flags [P.W], seq 158289:159737, ack 1, win 115, options [nop,nop,TS val 3115573 ecr 111212491], length 1448 > 19:30:54.446057 IP (tos 0x0, ttl 64, id 62100, offset 0, flags [DF], proto TCP (6), length 52) > 172.30.42.18.50103 > 172.30.42.19.50341: Flags [.E], cksum 0xac88 (incorrect -> 0xdce3), ack 159737, win 551, options [nop,nop,TS val 111212495 ecr 3115573], length 0 > > > > 19:30:54.448209 IP (tos 0x3,CE, ttl 64, id 52622, offset 0, flags [DF], proto TCP (6), length 1500) > 172.30.42.19.50341 > 172.30.42.18.50103: Flags [.W], seq 159737:161185, ack 1, win 115, options [nop,nop,TS val 3115613 ecr 111212495], length 1448 > 19:30:54.486057 IP (tos 0x0, ttl 64, id 62101, offset 0, flags [DF], proto TCP (6), length 52) > 172.30.42.18.50103 > 172.30.42.19.50341: Flags [.E], cksum 0xac88 (incorrect -> 0xd70f), ack 161185, win 551, options [nop,nop,TS val 111212499 ecr 3115613], length 0 > > 19:30:54.487443 IP (tos 0x3,CE, ttl 64, id 52623, offset 0, flags [DF], proto TCP (6), length 1500) > 172.30.42.19.50341 > 172.30.42.18.50103: Flags [.W], seq 161185:162633, ack 1, win 115, options [nop,nop,TS val 3115653 ecr 111212499], length 1448 > 19:30:54.526069 IP (tos 0x0, ttl 64, id 62102, offset 0, flags [DF], proto TCP (6), length 52) > 172.30.42.18.50103 > 172.30.42.19.50341: Flags [.E], cksum 0xac88 (incorrect -> 0xd13b), ack 162633, win 551, options [nop,nop,TS val 111212503 ecr 3115653], length 0 > > 19:30:54.527241 IP (tos 0x2,ECT(0), ttl 64, id 52624, offset 0, flags [DF], proto TCP (6), length 1500) > 172.30.42.19.50341 > 172.30.42.18.50103: Flags [.W], seq 162633:164081, ack 1, win 115, options [nop,nop,TS val 3115693 ecr 111212503], length 1448 > 19:30:54.566049 IP (tos 0x0, ttl 64, id 62103, offset 0, flags [DF], proto TCP (6), length 52) > 172.30.42.18.50103 > 172.30.42.19.50341: Flags [.], cksum 0xac88 (incorrect -> 0xcba7), ack 164081, win 551, options [nop,nop,TS val 111212507 ecr 3115693], length 0 > > 19:30:54.567809 IP (tos 0x3,CE, ttl 64, id 52625, offset 0, flags [DF], proto TCP (6), length 1500) > 172.30.42.19.50341 > 172.30.42.18.50103: Flags [.], seq 164081:165529, ack 1, win 115, options [nop,nop,TS val 3115733 ecr 111212507], length 1448 > 19:30:54.606067 IP (tos 0x0, ttl 64, id 62104, offset 0, flags [DF], proto TCP (6), length 52) > 172.30.42.18.50103 > 172.30.42.19.50341: Flags [.E], cksum 0xac88 (incorrect -> 0xc593), ack 165529, win 551, options [nop,nop,TS val 111212511 ecr 3115733], length 0 > 19:30:54.607088 IP (tos 0x2,ECT(0), ttl 64, id 52626, offset 0, flags [DF], proto TCP (6), length 1500) > 172.30.42.19.50341 > 172.30.42.18.50103: Flags [.W], seq 165529:166977, ack 1, win 115, options [nop,nop,TS val 3115773 ecr 111212511], length 1448 > 19:30:54.646056 IP (tos 0x0, ttl 64, id 62105, offset 0, flags [DF], proto TCP (6), length 52) > 172.30.42.18.50103 > 172.30.42.19.50341: Flags [.], cksum 0xac88 (incorrect -> 0xbfff), ack 166977, win 551, options [nop,nop,TS val 111212515 ecr 3115773], length 0 > 19:30:54.648105 IP (tos 0x3,CE, ttl 64, id 52627, offset 0, flags [DF], proto TCP (6), length 1500) > 172.30.42.19.50341 > 172.30.42.18.50103: Flags [.], seq 166977:168425, ack 1, win 115, options [nop,nop,TS val 3115813 ecr 111212515], length 1448 > > > > _______________________________________________ > Codel mailing list > Codel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/codel