[iccrg] Pareto frontier

Michael Welzl <michawe@ifi.uio.no> Wed, 08 January 2020 13:52 UTC

Return-Path: <michawe@ifi.uio.no>
X-Original-To: iccrg@ietfa.amsl.com
Delivered-To: iccrg@ietfa.amsl.com
Received: from localhost (localhost []) by ietfa.amsl.com (Postfix) with ESMTP id AB71512008B for <iccrg@ietfa.amsl.com>; Wed, 8 Jan 2020 05:52:02 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.901
X-Spam-Status: No, score=-1.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([]) by localhost (ietfa.amsl.com []) (amavisd-new, port 10024) with ESMTP id g43llQm_8io1 for <iccrg@ietfa.amsl.com>; Wed, 8 Jan 2020 05:52:00 -0800 (PST)
Received: from mail-out02.uio.no (mail-out02.uio.no [IPv6:2001:700:100:8210::71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 9D81912004C for <iccrg@irtf.org>; Wed, 8 Jan 2020 05:52:00 -0800 (PST)
Received: from mail-mx12.uio.no ([]) by mail-out02.uio.no with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92.3) (envelope-from <michawe@ifi.uio.no>) id 1ipBkb-000DSj-T8 for iccrg@irtf.org; Wed, 08 Jan 2020 14:51:57 +0100
Received: from boomerang.ifi.uio.no ([]) by mail-mx12.uio.no with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) user michawe (Exim 4.92.3) (envelope-from <michawe@ifi.uio.no>) id 1ipBkb-0006Md-CW for iccrg@irtf.org; Wed, 08 Jan 2020 14:51:57 +0100
From: Michael Welzl <michawe@ifi.uio.no>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: quoted-printable
Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\))
Message-Id: <510CB937-5E3B-4100-99E7-4F9AA3B81FEC@ifi.uio.no>
Date: Wed, 8 Jan 2020 14:51:55 +0100
To: iccrg IRTF list <iccrg@irtf.org>
X-Mailer: Apple Mail (2.3445.9.1)
X-UiO-SPF-Received: Received-SPF: neutral (mail-mx12.uio.no: is neither permitted nor denied by domain of ifi.uio.no) client-ip=; envelope-from=michawe@ifi.uio.no; helo=boomerang.ifi.uio.no;
X-UiO-Spam-info: not spam, SpamAssassin (score=-5.0, required=5.0, autolearn=disabled, UIO_MAIL_IS_INTERNAL=-5, uiobl=NO, uiouri=NO)
X-UiO-Scanned: 96E27FA7163C4CCE265072C7B40D94B587BA6CE7
Archived-At: <https://mailarchive.ietf.org/arch/msg/iccrg/DZu9yudSc2UwoQ3v0vx4eTvGC6w>
Subject: [iccrg] Pareto frontier
X-BeenThere: iccrg@irtf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Discussions of Internet Congestion Control Research Group \(ICCRG\)" <iccrg.irtf.org>
List-Unsubscribe: <https://www.irtf.org/mailman/options/iccrg>, <mailto:iccrg-request@irtf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/iccrg/>
List-Post: <mailto:iccrg@irtf.org>
List-Help: <mailto:iccrg-request@irtf.org?subject=help>
List-Subscribe: <https://www.irtf.org/mailman/listinfo/iccrg>, <mailto:iccrg-request@irtf.org?subject=subscribe>
X-List-Received-Date: Wed, 08 Jan 2020 13:52:03 -0000


Recently, it has become common in some congestion control papers, when showing plots with various congestion control mechanisms and a "better" arrow, to also draw a line through the presumably best mechanisms and call it a Pareto frontier.

I find it a bit of a stretch to just call this line a Pareto frontier - it MAY be one, but that's not proven, so I'm not sure this is a correct thing to state, strictly speaking. Anyway, I've recently seen cases where mechanism XY beats the others, as shown in the diagram, where it "sits comfortably outside the Pareto frontier".

Now, either I totally misunderstand something, or I never got the idea of Pareto efficiency, OR such a statement is utter nonsense.
(because being better than the mechanisms on the Pareto frontier simply means that this line is indeed *NOT* the Pareto frontier, and it was wrong to call it that in the first place).

Can someone enlighten me please?