From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x244.google.com (mail-pg0-x244.google.com [IPv6:2607:f8b0:400e:c05::244]) (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 1F6603B2A0 for ; Sat, 3 Dec 2016 16:07:43 -0500 (EST) Received: by mail-pg0-x244.google.com with SMTP id 3so11662208pgd.0 for ; Sat, 03 Dec 2016 13:07:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:subject:from:to:cc:date:in-reply-to:references :mime-version:content-transfer-encoding; bh=6sXK9uYpkM3PwRb9h75c2X4SmKwzmNdEdbA5mgug8jM=; b=MQh7Cp6oFxBm4nRLilOGZMUpsazSqYrZ8Q4kambHlHAFhdGNG71JAKUa/WCcSbdI70 6gXZmhuaVkko1TkZvxWVquGLL+qa6BnjXjQCT+x+XROhi5F4uo1BoESbFTj9bCe0nX6B I1yrRavpRTPloKPj8CYTIEZ/tndqX4YAmXfuRMR2bYEp4X1EvhT/nLlVW5LBzaLPbBLc xxDsV0wyYcqjIAJx/qJ9JK4cUp/OwP9Ywk9k0P4sSiOjvvlE4jrPW82IoHMYC/uEHl/d 82IVMxslX936X1KMouwWFimEHHvdfZASam7RsuK6hEMqgGyJJPUbH57/fT1ZB+P3AEPF dGyA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:subject:from:to:cc:date:in-reply-to :references:mime-version:content-transfer-encoding; bh=6sXK9uYpkM3PwRb9h75c2X4SmKwzmNdEdbA5mgug8jM=; b=eEckieAniRU8df/lXqbp89Y/+e58eN/jv3nuQVBmKYI5qq342eebEvuBF9Esa7xmv/ /Hq1NwYl2MQxZ5yV2HqJcTyS9wwXLjtQtvnS5OkKtCXWbIjIqDIbjHWxfKolY/wZiH9l qjm6CFN3wjDV+5800uA8xR8m4SlEQwAPIOmfMHyQnX3NDumwTjR0xvxqypoKoeVrpEoe vIIdqxHy8c/aIA9pyNIiFkiUmzT66trsaIdbeRTZaHSxiM2ZgSLTepA/EfLZ+qK02etU Tl9/nYyTjRBoIhhjv2Z2CI4kP70Fx+GkOK2EFEz3Zn53NkqwLc+Nnxz2hiKyphxB/kD9 Kdmw== X-Gm-Message-State: AKaTC01g0FBT4SGlaj01W/1R1SPyiJ1lJOD2bJCCEk6ZYhTCv3KKXyfjfAPMhzokXAJryg== X-Received: by 10.99.157.129 with SMTP id i123mr90083284pgd.148.1480799262317; Sat, 03 Dec 2016 13:07:42 -0800 (PST) Received: from [172.19.250.57] ([172.19.250.57]) by smtp.googlemail.com with ESMTPSA id s65sm16894649pgb.25.2016.12.03.13.07.40 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 03 Dec 2016 13:07:41 -0800 (PST) Message-ID: <1480799260.18162.418.camel@edumazet-glaptop3.roam.corp.google.com> From: Eric Dumazet To: Jonathan Morton Cc: "Steinar H. Gunderson" , Neal Cardwell , "aqm@ietf.org" , bloat Date: Sat, 03 Dec 2016 13:07:40 -0800 In-Reply-To: <9A821B94-143B-446F-8852-2EB0158DD57C@gmail.com> References: <56F6A3AB-3A47-4178-BEFF-04E3DC23B039@gmail.com> <20161202224006.GA5065@sesse.net> <1480721486.18162.392.camel@edumazet-glaptop3.roam.corp.google.com> <20161203191353.GA972@sesse.net> <1480796415.18162.408.camel@edumazet-glaptop3.roam.corp.google.com> <9A821B94-143B-446F-8852-2EB0158DD57C@gmail.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Bloat] TCP BBR paper is now generally available X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Dec 2016 21:07:43 -0000 On Sat, 2016-12-03 at 22:26 +0200, Jonathan Morton wrote: > > On 3 Dec, 2016, at 22:20, Eric Dumazet wrote: > > > > Huge ACK decimation it seems. > > That extract does not show ACK decimation. It shows either jumbo > frames or offload aggregation in a send burst, and ordinary > delayed-acks each covering at most two packets received. Nothing > particularly weird or unusual appears to be happening in the network. I do not attend IETF meetings so maybe my words are not exact. What I meant was that we receive ACKS in bursts, with huge gaps between them. Look at tsval/tsecr, and that all ACKS are received in a 20 usec time window, covering data that was sent in a 5 ms window. Looks the reverse path is severely congested or a device does ack filtering. 11:14:05.468643 IP6 C > S: Flags [.], ack 364280308, win 23430, options [nop,nop,TS val 864456877 ecr 3498315454], length 0 11:14:05.468645 IP6 C > S: Flags [.], ack 364288528, win 23407, options [nop,nop,TS val 864456877 ecr 3498315454], length 0 11:14:05.468646 IP6 C > S: Flags [.], ack 364296748, win 23415, options [nop,nop,TS val 864456877 ecr 3498315455], length 0 11:14:05.468648 IP6 C > S: Flags [.], ack 364302460, win 23400, options [nop,nop,TS val 864456877 ecr 3498315455], length 0 11:14:05.468650 IP6 C > S: Flags [.], ack 364304968, win 23430, options [nop,nop,TS val 864456877 ecr 3498315455], length 0 11:14:05.510870 IP6 C > S: Flags [.], ack 364313188, win 23407, options [nop,nop,TS val 864456877 ecr 3498315455], length 0 11:14:05.510885 IP6 C > S: Flags [.], ack 364321408, win 23415, options [nop,nop,TS val 864456877 ecr 3498315455], length 0 11:14:05.510888 IP6 C > S: Flags [.], ack 364328548, win 23396, options [nop,nop,TS val 864456877 ecr 3498315455], length 0 11:14:05.510890 IP6 C > S: Flags [.], ack 364335340, win 23419, options [nop,nop,TS val 864456877 ecr 3498315455], length 0 11:14:05.510892 IP6 C > S: Flags [.], ack 364337848, win 23430, options [nop,nop,TS val 864456877 ecr 3498315456], length 0 11:14:05.510894 IP6 C > S: Flags [.], ack 364353208, win 23389, options [nop,nop,TS val 864456877 ecr 3498315456], length 0 11:14:05.510895 IP6 C > S: Flags [.], ack 364362508, win 23411, options [nop,nop,TS val 864456877 ecr 3498315456], length 0 11:14:05.510897 IP6 C > S: Flags [.], ack 364370728, win 23415, options [nop,nop,TS val 864456877 ecr 3498315456], length 0 11:14:05.510899 IP6 C > S: Flags [.], ack 364378948, win 23419, options [nop,nop,TS val 864456877 ecr 3498315456], length 0 11:14:05.510900 IP6 C > S: Flags [.], ack 364384660, win 23404, options [nop,nop,TS val 864456877 ecr 3498315457], length 0 11:14:05.510902 IP6 C > S: Flags [.], ack 364387168, win 23430, options [nop,nop,TS val 864456877 ecr 3498315457], length 0 11:14:05.510904 IP6 C > S: Flags [.], ack 364394308, win 23411, options [nop,nop,TS val 864456877 ecr 3498315457], length 0 11:14:05.510905 IP6 C > S: Flags [.], ack 364403608, win 23411, options [nop,nop,TS val 864456877 ecr 3498315457], length 0 11:14:05.510907 IP6 C > S: Flags [.], ack 364411828, win 23419, options [nop,nop,TS val 864456878 ecr 3498315457], length 0