IETF Logo Mail Archive

Re: [PCN] Architecture draft - probing section & general updates.

Lars Eggert <lars.eggert@nokia.com> Fri, 19 October 2007 13:00 UTC

Return-path: <pcn-bounces@ietf.org>
Received: from [127.0.0.1] (helo=stiedprmman1.va.neustar.com) by megatron.ietf.org with esmtp (Exim 4.43) id 1IirT2-000735-DB; Fri, 19 Oct 2007 09:00:44 -0400
Received: from pcn by megatron.ietf.org with local (Exim 4.43) id 1IirT0-00071k-M5 for pcn-confirm+ok@megatron.ietf.org; Fri, 19 Oct 2007 09:00:42 -0400
Received: from [10.90.34.44] (helo=chiedprmail1.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1IirSz-00070T-EQ for pcn@ietf.org; Fri, 19 Oct 2007 09:00:41 -0400
Received: from smtp.nokia.com ([131.228.20.171] helo=mgw-ext12.nokia.com) by chiedprmail1.ietf.org with esmtp (Exim 4.43) id 1IirSy-0002UI-Sj for pcn@ietf.org; Fri, 19 Oct 2007 09:00:41 -0400
Received: from esebh105.NOE.Nokia.com (esebh105.ntc.nokia.com [172.21.138.211]) by mgw-ext12.nokia.com (Switch-3.2.5/Switch-3.2.5) with ESMTP id l9JD0WHg007843; Fri, 19 Oct 2007 16:00:36 +0300
Received: from esebh103.NOE.Nokia.com ([172.21.143.33]) by esebh105.NOE.Nokia.com with Microsoft SMTPSVC(6.0.3790.1830); Fri, 19 Oct 2007 15:58:28 +0300
Received: from mgw-int02.ntc.nokia.com ([172.21.143.97]) by esebh103.NOE.Nokia.com over TLS secured channel with Microsoft SMTPSVC(6.0.3790.1830); Fri, 19 Oct 2007 15:58:27 +0300
Received: from [172.21.34.110] (esdhcp034110.research.nokia.com [172.21.34.110]) by mgw-int02.ntc.nokia.com (Switch-3.2.5/Switch-3.2.5) with ESMTP id l9JCwQVE001319; Fri, 19 Oct 2007 15:58:26 +0300
In-Reply-To: <BABC859E6D0B9A4D8448CC7F41CD2B07054B382F@xmb-rtp-203.amer.cisco.com>
References: <BABC859E6D0B9A4D8448CC7F41CD2B07054B382F@xmb-rtp-203.amer.cisco.com>
Mime-Version: 1.0 (Apple Message framework v752.3)
Message-Id: <425EB9B7-F7DB-4895-9A68-47C0F709D196@nokia.com>
From: Lars Eggert <lars.eggert@nokia.com>
Subject: Re: [PCN] Architecture draft - probing section & general updates.
Date: Fri, 19 Oct 2007 15:58:26 +0300
To: ext Anna Charny <acharny@cisco.com>
X-Mailer: Apple Mail (2.752.3)
X-OriginalArrivalTime: 19 Oct 2007 12:58:27.0902 (UTC) FILETIME=[BDF97DE0:01C8124F]
X-Nokia-AV: Clean
X-Spam-Score: 0.0 (/)
X-Scan-Signature: 386e0819b1192672467565a524848168
Cc: pcn@ietf.org
X-BeenThere: pcn@ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: PCN WG list <pcn.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/pcn>, <mailto:pcn-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www1.ietf.org/pipermail/pcn>
List-Post: <mailto:pcn@ietf.org>
List-Help: <mailto:pcn-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/pcn>, <mailto:pcn-request@ietf.org?subject=subscribe>
Content-Type: multipart/mixed; boundary="===============1027957736=="
Errors-To: pcn-bounces@ietf.org

On 2007-10-16, at 21:55, ext Anna Charny (acharny) wrote:
> Yes, Robert's is a fair concern to which no obvious solution is in
> sight. Different equipment might use different algorithms and might  
> use
> different fields for ECMP load-balancing under different  
> circumstances.
> IMHO this is a killer argument of why the use of probing for  
> discovering
> the state of ECMP paths should not be considered within the scope  
> of PCN
> WG.

Agreed.

> There remains a question of whether probing can/should be considerd to
> probe the path regardless of the ECMP issue.  I see most of its  
> value in
> flash crowd situations in combination with low ingress-egress
> agregation.

I note that scenarios with low aggregation aren't in scope of the  
charter:

   The initial scope of the PCN WG is restricted by the following
   assumptions:
...
   (C) the number of flows across any potential aggregation bottleneck
   is sufficiently large for stateless, statistical mechanisms
   to be effective

Lars

_______________________________________________
PCN mailing list
PCN@ietf.org
https://www1.ietf.org/mailman/listinfo/pcn

v2.40.4 | Report a Bug | By Email | System Status