Re: [aqm] TCP ACK Suppression

"Francini, Andrea (Andrea)" <andrea.francini@alcatel-lucent.com> Wed, 07 October 2015 15:50 UTC

Return-Path: <andrea.francini@alcatel-lucent.com>
X-Original-To: aqm@ietfa.amsl.com
Delivered-To: aqm@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 716791ACC7F for <aqm@ietfa.amsl.com>; Wed, 7 Oct 2015 08:50:51 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.91
X-Spam-Level:
X-Spam-Status: No, score=-6.91 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, T_RP_MATCHES_RCVD=-0.01] autolearn=ham
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id qXitvGcBPBjH for <aqm@ietfa.amsl.com>; Wed, 7 Oct 2015 08:50:50 -0700 (PDT)
Received: from smtp-fr.alcatel-lucent.com (fr-hpida-esg-02.alcatel-lucent.com [135.245.210.21]) (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 C60B71AC82C for <aqm@ietf.org>; Wed, 7 Oct 2015 08:50:49 -0700 (PDT)
Received: from us70uusmtp3.zam.alcatel-lucent.com (unknown [135.5.2.65]) by Websense Email Security Gateway with ESMTPS id EDC1FCCF76E1B; Wed, 7 Oct 2015 15:50:43 +0000 (GMT)
Received: from US70TWXCHHUB04.zam.alcatel-lucent.com (us70twxchhub04.zam.alcatel-lucent.com [135.5.2.36]) by us70uusmtp3.zam.alcatel-lucent.com (GMO) with ESMTP id t97FoiZJ020126 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Wed, 7 Oct 2015 15:50:44 GMT
Received: from US70TWXCHMBA12.zam.alcatel-lucent.com ([169.254.6.242]) by US70TWXCHHUB04.zam.alcatel-lucent.com ([135.5.2.36]) with mapi id 14.03.0195.001; Wed, 7 Oct 2015 11:50:44 -0400
From: "Francini, Andrea (Andrea)" <andrea.francini@alcatel-lucent.com>
To: Steve Bauer <bauer@mit.edu>, "LAUTENSCHLAEGER, Wolfram (Wolfram)" <wolfram.lautenschlaeger@alcatel-lucent.com>
Thread-Topic: [aqm] TCP ACK Suppression
Thread-Index: AQHRAAfbJ/73TrlDIUOGwELhN8Uffp5eiGYAgAEb8WCAAIiqAP///eJg
Date: Wed, 7 Oct 2015 15:50:43 +0000
Message-ID: <1BFAC0A1D7955144A2444E902CB628F865B0C249@US70TWXCHMBA12.zam.alcatel-lucent.com>
References: <alpine.DEB.2.02.1510060748480.8750@uplift.swm.pp.se> <D2394BB6.548C5%g.white@cablelabs.com> <0A452E1DADEF254C9A7AC1969B8781284A7D9B66@FR712WXCHMBA13.zeu.alcatel-lucent.com> <CAFxEvqouQv-xkLWXxxBTw5swSFazWSb_Hak3ZOmnBSeQbE20hw@mail.gmail.com>
In-Reply-To: <CAFxEvqouQv-xkLWXxxBTw5swSFazWSb_Hak3ZOmnBSeQbE20hw@mail.gmail.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [135.5.27.17]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
Archived-At: <http://mailarchive.ietf.org/arch/msg/aqm/nZUL3CHy67kR2O45yhUYiG_wBz8>
Cc: Greg White <g.white@cablelabs.com>, "aqm@ietf.org" <aqm@ietf.org>
Subject: Re: [aqm] TCP ACK Suppression
X-BeenThere: aqm@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: "Discussion list for active queue management and flow isolation." <aqm.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/aqm>, <mailto:aqm-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/aqm/>
List-Post: <mailto:aqm@ietf.org>
List-Help: <mailto:aqm-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/aqm>, <mailto:aqm-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 07 Oct 2015 15:50:51 -0000

How about the effect of ACK suppression on the growth of the congestion window, for TCP sources where the trigger for window growth is the arrival of an ACK, not the number of bytes it acknowledges? 

The Appropriate Byte Counting (ABC) option (https://tools.ietf.org/html/rfc3465) was addressing a similar issue with delayed ACKs, but it looks like it is no longer available in Linux (http://www.spinics.net/lists/netdev/msg225164.html). 

Is there another workaround already available?

Andrea


-----Original Message-----
From: aqm [mailto:aqm-bounces@ietf.org] On Behalf Of Steve Bauer
Sent: Wednesday, October 07, 2015 7:41 AM
To: LAUTENSCHLAEGER, Wolfram (Wolfram)
Cc: Greg White; aqm@ietf.org
Subject: Re: [aqm] TCP ACK Suppression

On Wed, Oct 7, 2015 at 3:42 AM, LAUTENSCHLAEGER, Wolfram (Wolfram)
<wolfram.lautenschlaeger@alcatel-lucent.com>; wrote:
> Is this specialized upstream TCP ACK handling, particularly the
> prioritization a general recommendation in all access technologies?
> Perhaps it should be, since otherwise up and downstream TCP flows interfere
> in a crazy queue oscillation that is typically misinterpreted by AQMs.
> Is this topic addressed in some RFC already?

See:

RFC 3449: TCP Performance Implications of Network Path Asymmetry
https://tools.ietf.org/html/rfc3449

in particular section 5.2

     5.2 TYPE 1: Reverse Link Bandwidth Management ...................19
       5.2.1 ACK Filtering ...........................................20
       5.2.2 ACK Decimation ..........................................21

Steven Bauer
MIT

_______________________________________________
aqm mailing list
aqm@ietf.org
https://www.ietf.org/mailman/listinfo/aqm