From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cassarossa.samfundet.no (cassarossa.samfundet.no [IPv6:2001:67c:29f4::29]) (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 9E2F93B2A0 for ; Sat, 3 Dec 2016 14:13:57 -0500 (EST) Received: from pannekake.samfundet.no ([2001:67c:29f4::50] ident=unknown) by cassarossa.samfundet.no with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.84_2) (envelope-from ) id 1cDFkv-0003kl-Eg; Sat, 03 Dec 2016 20:13:53 +0100 Received: from sesse by pannekake.samfundet.no with local (Exim 4.84_2) (envelope-from ) id 1cDFkv-0009bi-C6; Sat, 03 Dec 2016 20:13:53 +0100 Date: Sat, 3 Dec 2016 20:13:53 +0100 From: "Steinar H. Gunderson" To: Neal Cardwell Cc: Eric Dumazet , Jonathan Morton , "aqm@ietf.org" , bloat Message-ID: <20161203191353.GA972@sesse.net> References: <56F6A3AB-3A47-4178-BEFF-04E3DC23B039@gmail.com> <20161202224006.GA5065@sesse.net> <1480721486.18162.392.camel@edumazet-glaptop3.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Operating-System: Linux 4.9.0-rc2 on a x86_64 User-Agent: Mutt/1.5.23 (2014-03-12) 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 19:13:57 -0000 On Sat, Dec 03, 2016 at 08:03:50AM -0500, Neal Cardwell wrote: > Thanks for the report, Steinar. This is the first report we've had > like this, but it would be interesting to find out what's going on. > > Even if you don't have time to apply the patches Eric mentions, it > would be hugely useful if the next time you have a slow transfer like > that you could post a link to a tcpdump packet capture (headers only > is best, say -s 120). Ideally the trace would capture a whole > connection, so we can see the wscale on the SYN exchange. I tried reproducing it now. I can't get as far down as 50 Mbit/sec, but it stopped around 100 Mbit/sec, still without any clear bottlenecks. cubic was just as bad, though. I've taken two tcpdumps as requested; I can't reboot this server easily right now, unfortunately. They are: http://storage.sesse.net/bbr.pcap -- ssh+tar+gnupg http://storage.sesse.net/bbr2.pcap -- wget between same hosts /* Steinar */ -- Homepage: https://www.sesse.net/