From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx144.netapp.com (mx144.netapp.com [216.240.21.25]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "mx144.netapp.com", Issuer "VeriSign Class 3 International Server CA - G3" (not verified)) by huchra.bufferbloat.net (Postfix) with ESMTPS id C9F9421F940 for ; Sun, 19 Jul 2015 01:26:15 -0700 (PDT) X-IronPort-AV: E=Sophos;i="5.15,502,1432623600"; d="scan'208";a="56886972" Received: from hioexcmbx08-prd.hq.netapp.com ([10.122.105.41]) by mx144-out.netapp.com with ESMTP; 19 Jul 2015 01:21:13 -0700 Received: from HIOEXCMBX05-PRD.hq.netapp.com (10.122.105.38) by hioexcmbx08-prd.hq.netapp.com (10.122.105.41) with Microsoft SMTP Server (TLS) id 15.0.1076.9; Sun, 19 Jul 2015 01:21:12 -0700 Received: from HIOEXCMBX05-PRD.hq.netapp.com ([::1]) by hioexcmbx05-prd.hq.netapp.com ([fe80::1438:d6b8:afb:4959%21]) with mapi id 15.00.1076.000; Sun, 19 Jul 2015 01:21:12 -0700 From: "Scheffenegger, Richard" To: =?iso-8859-1?Q?Mirja_K=FChlewind?= , Ingemar Johansson S Thread-Topic: [iccrg] ECN issues Thread-Index: AQHQr3mo1P0XVF5qDkexb2Xwbl2Li53D7D4AgB6rLkA= Date: Sun, 19 Jul 2015 08:21:12 +0000 Message-ID: References: <81564C0D7D4D2A4B9A86C8C7404A13DA34B30B4C@ESESSMB205.ericsson.se> <04ED8D23-53C3-4F12-9647-3A07FFB43352@tik.ee.ethz.ch> <81564C0D7D4D2A4B9A86C8C7404A13DA34B3230A@ESESSMB205.ericsson.se> <6D65AC6E-4AA1-4F8C-B758-D63EEC59A0E2@tik.ee.ethz.ch> In-Reply-To: <6D65AC6E-4AA1-4F8C-B758-D63EEC59A0E2@tik.ee.ethz.ch> Accept-Language: de-AT, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.122.56.79] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "cheshire@apple.com" , "iccrg@irtf.org" , "Bob Briscoe \(bob.briscoe@bt.com\)" , "bloat@lists.bufferbloat.net" , "ietf@trammell.ch" Subject: Re: [Bloat] [iccrg] ECN issues 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: Sun, 19 Jul 2015 08:26:45 -0000 Hi Ingemar, I was to make that very same point; from my earlier collaboration with Mirj= a and Brians efforts, I think the prevalence of gear that still uses a noti= on of a TOS byte, and rewrites it for a L4 flow is actually higher than ECN= impacting connection set up etc. So, on some paths you may believe you negotiate ECN, but one half-link may = bleach the IP-header ECN bits. Again, this is detectable for the receiver (currently, no mechanism to conv= ey this info back to a TCP sender), and affected sessions would revert back= to loss-based CC. Such ECN-unresponsive, loss-responsive flows may pose an issue to AQMs that= do some differentiated handling of ECN vs non-ECN packets though... Best regards, Richard > -----Original Message----- > From: iccrg [mailto:iccrg-bounces@irtf.org] On Behalf Of Mirja K=FChlewin= d > Sent: Montag, 29. Juni 2015 14:56 > To: Ingemar Johansson S > Cc: cheshire@apple.com; iccrg@irtf.org; Dave Taht (dave.taht@gmail.com); > Bob Briscoe (bob.briscoe@bt.com); bloat@lists.bufferbloat.net; > ietf@trammell.ch > Subject: Re: [iccrg] ECN issues >=20 > Hi Ingemar, >=20 > we did only test connection setup up and some small transmissions so far. > We did not measurement anything with longer connection though. However, > from these results I'd also say there are no mayor issues anymore. There > are still some boxes that overwrite the IP ECN bits because they still > think it's part of the ToS field. However, those cases are rather easy to > detect because all packets should have the same marking. Linux implements > an easy fallback where ECN is disabled if the SYN is ECN marked. That's > probably not the perfect solution but mostly helps the problem. >=20 > Mirja >=20 >=20 > > Am 25.06.2015 um 21:02 schrieb Ingemar Johansson S > : > > > > Hi > > > > And thanks all for the info both on and off list. I believe that I have > enough information. The main objective for me was to get an understanding > how serious the issues that various boxes in the middle (e.g NATs/FWs ) > mess with the ECN bits really is. Seems to me, based on the info I > received thus far that this is becoming more and more an non-issue ?. > > > > Realized that I have seen the below paper before, somehow I mixed it > > up with the older paper, have to blame it on my own teflon-memory ... > > Thanks for refreshing my memory > > > > /Ingemar > > > >> -----Original Message----- > >> From: Mirja K=FChlewind [mailto:mirja.kuehlewind@tik.ee.ethz.ch] > >> Sent: den 25 juni 2015 19:31 > >> To: Ingemar Johansson S > >> Cc: bloat@lists.bufferbloat.net; iccrg@irtf.org; Bob Briscoe > >> (bob.briscoe@bt.com); ietf@trammell.ch; Dave Taht > >> (dave.taht@gmail.com); cheshire@apple.com > >> Subject: Re: ECN issues > >> > >> Hi Ingemar, > >> > >> there is a newer paper we published last year (and gave a quick > >> presentation at the last ICCRG meeting): > >> > >> http://wan.poly.edu/pam2015/papers/4.pdf > >> > >> https://www.ietf.org/proceedings/92/slides/slides-92-iccrg-1.pdf > >> > >> In the mean time we did more measurements using BitTorrent clients > >> instead. The results are very similar. We might be able to quickly > >> present some new results at the next session (if the session takes > >> place and there is still space). > >> > >> Does this help or are you looking for some specific information? > >> > >> Mirja > >> > >> > >>> Am 24.06.2015 um 13:34 schrieb Ingemar Johansson S > >> : > >>> > >>> Hi > >>> > >>> I wonder, is there any new data around that gives any ideas how > >>> large the > >> issues with ECN really are ?. > >>> > >>> Issues that I am interested are ECN black holes and faulty remarking > >>> of ECN fields > >>> > >>> The last one I have seen is this paper by Mirja, Brian and Sebastian > >>> Neuner > >>> http://www.ict-mplane.eu/sites/default/files/public/publications/311 > >>> ec > >>> ndeployment.pdf > >>> > >>> Is there any new data available ?. > >>> > >>> /Ingemar > >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > >>> Ingemar Johansson M.Sc. > >>> Senior Researcher > >>> > >>> Ericsson AB > >>> Wireless Access Networks > >>> Labratoriegr=E4nd 11 > >>> 971 28, Lule=E5, Sweden > >>> Phone +46-1071 43042 > >>> SMS/MMS +46-73 078 3289 > >>> ingemar.s.johansson@ericsson.com > >>> www.ericsson.com > >>> > >>> "No man has a good enough memory > >>> to be a successful liar" > >>> Abraham Lincoln > >>> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D >=20 > _______________________________________________ > iccrg mailing list > iccrg@irtf.org > https://www.irtf.org/mailman/listinfo/iccrg