From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-12-ewr.dyndns.com (mxout-135-ewr.mailhop.org [216.146.33.135]) by lists.bufferbloat.net (Postfix) with ESMTP id D90992E011F for ; Fri, 11 Mar 2011 10:10:18 -0800 (PST) Received: from scan-12-ewr.mailhop.org (scan-12-ewr.local [10.0.141.230]) by mail-12-ewr.dyndns.com (Postfix) with ESMTP id 0A2F1934761 for ; Fri, 11 Mar 2011 18:10:18 +0000 (UTC) X-Spam-Score: 0.1 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 75.145.127.229 Received: from gw.co.teklibre.org (75-145-127-229-Colorado.hfc.comcastbusiness.net [75.145.127.229]) by mail-12-ewr.dyndns.com (Postfix) with ESMTP id A47FF9346F9 for ; Fri, 11 Mar 2011 18:10:17 +0000 (UTC) Received: from cruithne.co.teklibre.org (unknown [IPv6:2002:4b91:7fe5:1::20]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "cruithne.co.teklibre.org", Issuer "CA Cert Signing Authority" (verified OK)) by gw.co.teklibre.org (Postfix) with ESMTPS id 1EE605E9AD for ; Fri, 11 Mar 2011 11:10:17 -0700 (MST) Received: by cruithne.co.teklibre.org (Postfix, from userid 1000) id 5BA1E120844; Fri, 11 Mar 2011 11:10:16 -0700 (MST) From: d@taht.net (Dave =?utf-8?Q?T=C3=A4ht?=) To: Jonathan Morton Organization: Teklibre - http://www.teklibre.com References: <6210AF7E-3EB3-4199-A87B-A54B0F73A106@gmail.com> <20110311092157.23dea5e8@nehalam> Date: Fri, 11 Mar 2011 11:10:16 -0700 In-Reply-To: (Jonathan Morton's message of "Fri, 11 Mar 2011 20:00:55 +0200") Message-ID: <874o79r0jb.fsf@cruithne.co.teklibre.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stephen Hemminger , bloat@lists.bufferbloat.net Subject: Re: [Bloat] Taxonomy of various sender-side TCPs X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Mar 2011 18:10:19 -0000 Jonathan Morton writes: > On 11 Mar, 2011, at 7:21 pm, Stephen Hemminger wrote: > >>> 2: Illinois, Compound >> (Add in Yeah, Veno, and TCP-NV ) >>> Strategy: Fill the pipe quickly, then probe the buffer slowly to >>> avoid being outcompeted. > > I separated Veno to put it with Westwood, because there is almost no > difference between Veno and Westwood, and they do not advance more > rapidly than Reno in the uncongested regime. I consider those two > more aggressive than Reno only because they back off less if they > believe the link is not congested, and that belief has a chance of > being incorrect. > > Meanwhile I considered Illinois and Compound to be less aggressive > than Reno because they explicitly advance less rapidly in the > congested regime, and back off at least as effectively as Reno does > (well, the Linux implementation of Compound - it seems M$ screwed up > their version). > > I haven't read up on Yeah and NV (or TCP-fit) yet, so I can't classify > them. I'm also aware that a number of other aggressive TCPs designed > for LFN throughput exist, but I can't be bothered enumerating them > because they are useless - obsoleted by CUBIC in their intended > application, and too aggressive for the wider Internet. > > I do agree that TCPs which attempt to probe for minRTT have a weakness > in this area, and Vegas is particularly weak because it relies very > heavily on minRTT and is also very timid. If the whole Internet used > Vegas this wouldn't be a problem, but it gets outcompeted badly by > literally everything else, especially the extra-aggressive TCPs like > CUBIC. So simply changing the send-side TCP congestion algorithm is > insufficient to solve the whole problem, though some classes of users > are seeing benefits from using Vegas despite it's flaws. Several freeswitch (VOIP) folk said they were using Vegas for the TCP side of their servers due to it's lower impact for command and control applications while lots of RTP streams were running. One claimed that Vegas is what google uses, but that's unconfirmed. Discussion here (including recording) http://www.bufferbloat.net/projects/bloat/wiki/Bufferbloat_and_Freeswitch_Conference_Call_March_9 Also, for those new to the list, there was a huge LEDBAT thread here earlier and interest in embedding that into the kernel. https://lists.bufferbloat.net/pipermail/bloat/2011-February/000025.html And split-tcp solutions were discussed here: https://lists.bufferbloat.net/pipermail/bloat/2011-February/000068.html > > - Jonathan > > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat -- Dave Taht http://nex-6.taht.net