Re: [pilc] Bidirectionnal traffic over assymetric link

Dr G Fairhurst <gorry@erg.abdn.ac.uk> Tue, 23 July 2002 15:56 UTC

Received: from optimus.ietf.org (ietf.org [132.151.1.19] (may be forged)) by ietf.org (8.9.1a/8.9.1a) with ESMTP id LAA19652 for <pilc-archive@odin.ietf.org>; Tue, 23 Jul 2002 11:56:16 -0400 (EDT)
Received: from optimus.ietf.org (localhost [127.0.0.1]) by optimus.ietf.org (8.9.1a/8.9.1) with ESMTP id LAA20565; Tue, 23 Jul 2002 11:42:20 -0400 (EDT)
Received: from ietf.org (odin [132.151.1.176]) by optimus.ietf.org (8.9.1a/8.9.1) with ESMTP id LAA20532 for <pilc@optimus.ietf.org>; Tue, 23 Jul 2002 11:42:17 -0400 (EDT)
Received: from erg.abdn.ac.uk (mavis.erg.abdn.ac.uk [139.133.204.77]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id LAA18965 for <pilc@ietf.org>; Tue, 23 Jul 2002 11:41:15 -0400 (EDT)
Received: from erg.abdn.ac.uk (gresley.erg.abdn.ac.uk [139.133.207.106]) by erg.abdn.ac.uk (8.12.5/8.12.5) with ESMTP id g6NFf7nv012576; Tue, 23 Jul 2002 16:41:07 +0100 (BST)
Message-ID: <3D3D7914.8472C5D8@erg.abdn.ac.uk>
Date: Tue, 23 Jul 2002 16:41:09 +0100
From: Dr G Fairhurst <gorry@erg.abdn.ac.uk>
Reply-To: gorry@erg.abdn.ac.uk
Organization: ERG, Aberdeen, UK
X-Mailer: Mozilla 4.77C-CCK-MCD {C-UDP; EBM-APPLE} (Macintosh; U; PPC)
X-Accept-Language: en
MIME-Version: 1.0
To: Fatma Louati <Fatma.Louati@sophia.inria.fr>
CC: end2end-interest@postel.org, pilc@ietf.org
Subject: Re: [pilc] Bidirectionnal traffic over assymetric link
References: <3D3D4D2E.2070708@sophia.inria.fr>
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
X-MailScanner: Found to be clean
Content-Transfer-Encoding: 7bit
Sender: pilc-admin@ietf.org
Errors-To: pilc-admin@ietf.org
X-Mailman-Version: 1.0
Precedence: bulk
List-Id: Performance Implications of Link Characteristics IETF Working Group <pilc.ietf.org>
X-BeenThere: pilc@ietf.org
Content-Transfer-Encoding: 7bit

One thing you may like to look at is the internet draft developed
by the PILC WG on this topic.

http://www.ietf.org/html.charters/pilc-charter.html

The draft is at:

http://www.ietf.org/internet-drafts/draft-ietf-pilc-asym-07.txt

and has been recommended to the IESG for publication as a RFC.


The draft talks of many of the issues you mention (plus a few more).

If you'd like to know more, or have further questions, you are welcome
to email me directly, and I'll try to help.

best wishes,

Gorry Fairhurst


Fatma Louati wrote:
> 
>   Hi,
> 
> I have made some simulations of bidirectionnal TCP traffic passing
> through an assymmetric link, evolving several simultaneous connections
> in both direction. It seems that the combination of using AckFiltering
> and Ack Reconstruction, AckFirst scheduling and an Active Queue
> Management like RED gives the best results in term of global throughput.
> 
> In fact the asymmetry that forward connections encounter necessitate the
> use of AF/AR, however the presence of traffic in the other direction
> implies the use of an AckFirst scheduling to protect ACKs against Data
> packets. But limited buffer size will result in a ACK packets
> monopolization. That's why I thought about using a AQM mechanisms in the
> router. This solution gives also an acceptable fairness among the
> different flows.
> 
> Before I go further in this direction I would like to know what do you
> think about it.
> Could you please tell me if you are aware of recent work on this domain.
> 
> Thanx
> 
> Fatma Louati -
> PhD Student - INRIA Sophia Antipolis
> http://www.inria.fr/planete/flouati <http://www.inria.fr/planete/dabbous>
> ps: Simulations topology is accessible in
> http://www-sop.inria.fr/planete/louati/topo2Way.eps
> 
> _______________________________________________
> pilc mailing list
> pilc@ietf.org
> https://www1.ietf.org/mailman/listinfo/pilc
> http://www.ietf.org/html.charters/pilc-charter.html
> http://pilc.grc.nasa.gov/

_______________________________________________
pilc mailing list
pilc@ietf.org
https://www1.ietf.org/mailman/listinfo/pilc
http://www.ietf.org/html.charters/pilc-charter.html
http://pilc.grc.nasa.gov/