From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) (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 B8D173B2A4; Sun, 26 Apr 2020 19:33:19 -0400 (EDT) Received: by mail-pg1-x52e.google.com with SMTP id g6so7811172pgs.9; Sun, 26 Apr 2020 16:33:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=A0+NaGgPBZnrh0zdeA6sUgZ4nJPXPjnnWi+TVz/SHiE=; b=cEHSOTZQWYCkJt9JBZHxe7VHzuq9O5Y1eCeGpjyfkECCcrB3z+zncs8O3vt8bi36c6 IV3FvJMuaJeBwyTxuiWmXTMVyYWdizAaBvEvUYcK3gq6VcuTSuYaUZ4w9n0pIpjf3vRC dBmrnbm/RhsRLsCW4zvQMChaebD53ZkH6NnRPEJiSt9j3P64nwUW1xFebQkLTqN0tIXk vrK4FZ+S46M09f9mmu8CRu0Va0aLIBki9lzQPMNIEONegtC7g/7hxHeHydnosNGRmA1o 0NslPSSReof86mEFAvaKGCqIfogHLvZGcAPIbB9wYwrDSeHeU8+NHeF9D0lkhep7Aulb fvVg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=A0+NaGgPBZnrh0zdeA6sUgZ4nJPXPjnnWi+TVz/SHiE=; b=DyKEIhnu5RlAeTHZ5BlyQkYIG61sokbIBTy+ONyLzKmkLZK2XKOa4QRMuhGVLso3s+ R7bRieyRLmD7VlWxA06+yKZBo64ecle0WjX+8SP7vdR4vgZcV7xvICCysSemWizi42X2 U3s1PXeVpSkK3ww5pZ7GnPQ1FgV2Vkw3qK3lSIfO/ymF7fzDXFabLdyh2KW48rLFGDWj s79dHvjsKP2qKyh0735a7kwIlekmJG39Sdw927iMk/TwsPDibsXs8nVAUAvct28L+S8/ tRUrnHN4bI/dzPtHVR9iHMNQ+wWZvTPIldRPn7XuE83MD/2F/QjwUbx2iWHubCxrl43S okKA== X-Gm-Message-State: AGi0Puax3NGc+nLsC151AnPK8iFZsnHUpx6+pXGlrc4liSGXDVZp087h AV/ivNGtwWfYqmPWXuxgdxY= X-Google-Smtp-Source: APiQypIdTXjvmtEiyEY4z4iJIKvTgODB8fUft5/8ZOmq0Vr0HujKiZN5Eq+ShMDcqaY8G/KOmmzmKQ== X-Received: by 2002:a63:cf10:: with SMTP id j16mr19969004pgg.201.1587943998831; Sun, 26 Apr 2020 16:33:18 -0700 (PDT) Received: from [172.18.209.210] (c-76-103-225-85.hsd1.ca.comcast.net. [76.103.225.85]) by smtp.gmail.com with ESMTPSA id f30sm9883857pje.29.2020.04.26.16.33.17 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 26 Apr 2020 16:33:18 -0700 (PDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.80.23.2.2\)) From: Alexey Ivanov In-Reply-To: Date: Sun, 26 Apr 2020 16:33:15 -0700 Cc: Jonathan Morton , ECN-Sane , bloat Content-Transfer-Encoding: quoted-printable Message-Id: References: <85F248E2-E1B5-45A6-8E45-EBCA43B82A09@gmail.com> To: Neal Cardwell X-Mailer: Apple Mail (2.3608.80.23.2.2) Subject: Re: [Bloat] dropbox, bbr and ecn packet capture 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: Sun, 26 Apr 2020 23:33:19 -0000 Yep these are BBRv1 nodes with an older kernel (without even wifi = patches[1]) so their TCP performance is quite suboptimal. Once we update Edge to 5.4 we'll start the global BBRv2 rollout to all = PoPs. In the mean time, when you hit www.dropbox.com you should expect = (with a very high probability) that you are hitting a BBRv1 endpoint. [1] = https://lore.kernel.org/netdev/20190123200454.260121-3-priyarjha@google.co= m/#t -- t: @SaveTheRbtz > On Apr 25, 2020, at 8:10 PM, Neal Cardwell via Bloat = wrote: >=20 >=20 > From: Neal Cardwell > Subject: Re: [Bloat] dropbox, bbr and ecn packet capture > Date: April 25, 2020 at 8:10:11 PM PDT > To: Jonathan Morton > Cc: Dave Taht , ECN-Sane = , bloat >=20 >=20 >=20 >=20 > On Sat, Apr 25, 2020 at 8:52 PM Jonathan Morton = wrote: > > On 26 Apr, 2020, at 3:36 am, Dave Taht wrote: > >=20 > > I just did a rather large dropbox download. They are well known to = be > > using bbr and experimenting with bbrv2. So I fired off a capture > > during a big dropbox download... > >=20 > > It negotiated ecn, my fq_codel shaper and/or my newly ath10k > > fq_codel's wifi exerted CE, osx sent back ecn-echo, and the rtt > > results were lovely. However, there is possibly not a causal > > relationship here, and if anyone is bored and wants to scetrace, > > tcptrace or otherwise tear this cap apart, go for it. >=20 > Well, the CE response at their end is definitely not Multiplicative = Decrease. I haven't dug into it more deeply than that. But they're = also not running AccECN, nor are they "proactively" sending CWR to get a = "more accurate" CE feedback. I suspect they're running BBRv1 in this = one. >=20 > Agreed, that looks like BBRv1. I see a few BBRv1 PROBE_RTT phases in = there. >=20 > Thanks for the trace! >=20 > best, > neal >=20 >=20 >=20 > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat