From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-x232.google.com (mail-ig0-x232.google.com [IPv6:2607:f8b0:4001:c05::232]) (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 4080C3B492 for ; Wed, 20 Apr 2016 18:53:20 -0400 (EDT) Received: by mail-ig0-x232.google.com with SMTP id m9so50928478ige.1 for ; Wed, 20 Apr 2016 15:53:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-transfer-encoding; bh=cp/3F88PjGr4AF+SxyAG7p7wZAQYt6U1z/KHsqllcSg=; b=zOEjmWzzLBVRoH/MU479apHkWBxDiXgzP0V0lXj+9QaXPiwUzsojp1v204VQUrFfVC gSv9w6WxIxWogqnWuFpWLK/agbG4uMjd74FSnO1gLeWX5dvrAzC7Ftg5HhZd0HNnvvRa i+8sWM1SB4Ho05QSskLaUdXtMA3L3chaaQwLtR8Tf+Kz8D+UKfK+dnJ03VG7XYYK5jqm 9L0jsTwSRjMCrpcRAhC9mC5Z/3SNsqDXijCyzony5MsbTEvTTJCm7r0s7CUwFspOvr3s 99CnWMaYjQnXT7sbqcceu05+jc+CpCKTClIqdFNInsK7gNokXDAAdhkfCGfQru2yyU/L iSag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:date :message-id:subject:from:to:cc:content-transfer-encoding; bh=cp/3F88PjGr4AF+SxyAG7p7wZAQYt6U1z/KHsqllcSg=; b=g5VjASy+LzwH9yLFPjfOimQqPdg/m/YfQjDjMkcvriaogZlBDSdvEQZbrIG6YkUugn bcPUaqPCten/Pna8jUcYdnA2PiWH+JdmD4MgdQ3tiYRAovz4Slkg77l7eFFLsTvwcA+h c4NMwWsfT4407mf6lg2fFa+I6Eru+BdvoccRwlpoNWArnkPfbPRrLaneQE3vRZv1kg3U Zmqys7dnQFN3zNBVeJPir/V8HQrxDO9MtTV3SYpHKuIunMNRRKPHsWluIfQ/KqdtUvl9 CA+8ROmCCplhBj1VYgihG6QRnkZsMA+ZmdGnrFTllw0ONz8+FLfQwRGRn9WwaSmi/S1a TDKQ== X-Gm-Message-State: AOPr4FUwqd/6PnnParcxjH4QQobBLKVEmp3VmARJy4Dvd07VidNDR4B6A7vZRf5GMCFe3RC8zQDKvjuL/KgWKA== MIME-Version: 1.0 X-Received: by 10.50.55.194 with SMTP id u2mr3981465igp.41.1461192799647; Wed, 20 Apr 2016 15:53:19 -0700 (PDT) Sender: justinbeech@gmail.com Received: by 10.50.178.102 with HTTP; Wed, 20 Apr 2016 15:53:19 -0700 (PDT) In-Reply-To: References: Date: Thu, 21 Apr 2016 08:53:19 +1000 X-Google-Sender-Auth: VubgQdX1N21wS2PkriVGGjd0ikk Message-ID: From: jb To: Jonathan Morton Cc: "Livingood, Jason" , bloat Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [Bloat] dslreports bufferbloat tests 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: Wed, 20 Apr 2016 22:53:20 -0000 thanks And yes Dave, some logged tests (if we pre-arrange what day, and you tell me the UTCs) using this particular server would be good, I'll be in touch on that, I have to setup a capture that just isolates your IP. So Is there anything different, or detectable, on the server side for such a fully congestion aware connection, but no congestion is encountered? So on upload phase, I can see CE marks come in, but during download phase there is nothing interesting to detect and log? On Wed, Apr 20, 2016 at 10:43 PM, Jonathan Morton w= rote: > >> On 20 Apr, 2016, at 09:06, jb wrote: >> >> So this particular snap from the first 200 packets of a download there >> are poor RTTs but it also picked up the IP ecn_capable flag (but not >> the IP ecn congestion flag) and it picked up the TCP ece and cwr flags >> on. > > The TCP ECE and CWR flags are always set during ECN negotiation. If ther= e are no CE marks subsequently, they will not appear again once the data ph= ase begins. You can therefore distinguish between ECN capability of the ho= st and the network. > > For a =E2=80=9Cdownload=E2=80=9D test, your sender will see ECE flags inb= ound and generate CWR flags outbound *during the data phase* only if there = is an ECN aware AQM on the path at the bottleneck. It will not see the CE = marks themselves, as those are only present between the bottleneck and the = receiver. > > For an =E2=80=9Cupload" test, your receiver will see the inbound CE marks= from an AQM active on the bottleneck, respond to them with ECE flags, and = receive CWR flags in reply. Again, only during the data phase. > > - Jonathan Morton >