IETF Logo Mail Archive

Re: [tcpm] WGLC: TCP's Reaction to Soft Errors

Saikat Guha <saikat@cs.cornell.edu> Wed, 02 May 2007 12:45 UTC

Return-path: <tcpm-bounces@ietf.org>
Received: from [127.0.0.1] (helo=stiedprmman1.va.neustar.com) by megatron.ietf.org with esmtp (Exim 4.43) id 1HjECs-0003xQ-Os; Wed, 02 May 2007 08:45:18 -0400
Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1HjECr-0003v7-DH for tcpm@ietf.org; Wed, 02 May 2007 08:45:17 -0400
Received: from exchfenlb-2.cs.cornell.edu ([128.84.97.34] helo=exchfe2.cs.cornell.edu) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1HjECq-0005PH-5C for tcpm@ietf.org; Wed, 02 May 2007 08:45:17 -0400
Received: from exchfe1.cs.cornell.edu ([128.84.97.33]) by exchfe2.cs.cornell.edu with Microsoft SMTPSVC(6.0.3790.1830); Wed, 2 May 2007 08:45:15 -0400
Received: from [172.23.16.21] ([172.23.16.21]) by exchfe1.cs.cornell.edu over TLS secured channel with Microsoft SMTPSVC(6.0.3790.1830); Wed, 2 May 2007 08:45:14 -0400
Subject: Re: [tcpm] WGLC: TCP's Reaction to Soft Errors
From: Saikat Guha <saikat@cs.cornell.edu>
To: mallman@icir.org, 'Fernando Gont' <fernando@gont.com.ar>
In-Reply-To: <20070425034624.117871E18C7@lawyers.icir.org>
References: <20070425034624.117871E18C7@lawyers.icir.org>
Organization: Cornell University
Date: Wed, 02 May 2007 08:45:23 -0400
Message-Id: <1178109923.25526.63.camel@localhost.localdomain>
Mime-Version: 1.0
X-Mailer: Evolution 2.6.3 (2.6.3-1.fc5.5)
X-OriginalArrivalTime: 02 May 2007 12:45:15.0085 (UTC) FILETIME=[BB31B7D0:01C78CB7]
X-Spam-Score: 0.0 (/)
X-Scan-Signature: c1c65599517f9ac32519d043c37c5336
Cc: tcpm@ietf.org, Ted Faber <faber@ISI.EDU>
X-BeenThere: tcpm@ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: TCP Maintenance and Minor Extensions Working Group <tcpm.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/tcpm>, <mailto:tcpm-request@ietf.org?subject=unsubscribe>
List-Post: <mailto:tcpm@ietf.org>
List-Help: <mailto:tcpm-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/tcpm>, <mailto:tcpm-request@ietf.org?subject=subscribe>
Content-Type: multipart/mixed; boundary="===============1221715871=="
Errors-To: tcpm-bounces@ietf.org

On Tue, 2007-04-24 at 23:46 -0400, Mark Allman wrote:
> >         Title           : TCP's Reaction to Soft Errors
> > 	Author(s)       : F. Gont
> > 	Filename        : draft-ietf-tcpm-tcp-soft-errors-05.txt

I read the draft, and to the extent that the draft is informational and
does not standardize treating soft-errors as hard I have no objections.

The behavior described by the draft (that of considering soft errors as
hard during SYN-SENT state after 0/n retransmissions), however, was a
cause of concern for the NAT TCP Behavior document
(draft-ietf-behave-tcp-07.txt), which is currently in the RFC editors
queue. In that document, NATs are basically recommended to silently
delay any ICMP errors by 6 seconds to avoid triggering any of the
mechanism proposed in this document (proviso endpoints can coordinate to
exchange SYN packets through that 6 second hole).

IMHO it would help to point out in Section 3 (Problems that may arise
from TCP's reaction to soft errors) and Section 6.2 (Possible drawbacks:
Deterministic transient network failures) that stacks that treat ICMP
soft errors as hard during connection initiation (at least in the first
6 seconds) make it difficult for applications attempting to initiate TCP
Simultaneous-Open through a BEHAVE compliant NAT.

cheers,
-- 
Saikat

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

v2.23.0 | Report a Bug | By Email