Subject: I-D Action:draft-ietf-tsvwg-ecn-tunnel-09.txt

From: [email-masked]
Date: Mon, 2 Aug 2010 06:30:03 -0700 (PDT)

A New Internet-Draft is available from the on-line Internet-Drafts directories.
This draft is a work item of the Transport Area Working Group Working Group of the IETF.

	Title           : Tunnelling of Explicit Congestion Notification
	Author(s)       : B. Briscoe
	Filename        : draft-ietf-tsvwg-ecn-tunnel-09.txt
	Pages           : 42
	Date            : 2010-08-02

This document redefines how the explicit congestion notification
(ECN) field of the IP header should be constructed on entry to and
exit from any IP in IP tunnel.  On encapsulation it updates RFC3168
to bring all IP in IP tunnels (v4 or v6) into line with RFC4301 IPsec
ECN processing.  On decapsulation it updates both RFC3168 and RFC4301
to add new behaviours for previously unused combinations of inner and
outer header.  The new rules ensure the ECN field is correctly
propagated across a tunnel whether it is used to signal one or two
severity levels of congestion, whereas before only one severity level
was supported.  Tunnel endpoints can be updated in any order without
affecting pre-existing uses of the ECN field, thus ensuring backward
compatibility.  Nonetheless, operators wanting to support two
severity levels (e.g. for pre-congestion notification--PCN) can
require compliance with this new specification.  A thorough analysis
of the reasoning for these changes and the implications is included.
In the unlikely event that the new rules do not meet a specific need,
RFC4774 gives guidance on designing alternate ECN semantics and this
document extends that to include tunnelling issues.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-tsvwg-ecn-tunnel-09.txt

Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/

Below is the data which will enable a MIME compliant mail reader
implementation to automatically retrieve the ASCII version of the
Internet-Draft.

---

From: Bob Briscoe <[email-masked]>
Date: Mon, 02 Aug 2010 15:43:17 +0100

tsvwg folks,

To satisfy the review comments ecn-tunnel received while going 
through IETF last call and GENART review, I've revised it to draft-09 
before it goes to the IESG. No changes to technical content - only editorial.

The changes are listed within the doc which is here:
<http://tools.ietf.org/wg/tsvwg/draft-ietf-tsvwg-ecn-tunnel/>
I have also repeated them below:

    From ietf-08 to ietf-09 (current):  Added change log entry for -07 to
       -08 that was previously omitted.

       *  Changes to standards action text:

          +  Added RFC4774 to 'Updates:' header (the draft always has
             extended the advice in RFC4774 (BCP124) which said very
             little about tunnels.  The GENART reviewer merely pointed
             out that the header did not highlight this fact.)

       *  Editorial changes:

          +  Abstract: s/providing backward compatibility./thus ensuring
             backward compatibility./

          +  Moved PCN-related text motivating changes to decapsulation
             from "Default Tunnel Egress Behaviour" (Section 4.2) to
             "Motivation for Changing Decapsulation" (Section 5.3.2)
             where it was merged with existing similar text.

          +  In the non-normative Design Principles avoided using words
             in lower case where they were in contexts that might make
             them confusable with upper case RFC2119 normative language.

          +  Added Stephen Hanna and Ben Campbell to acks and corrected
             spelling of Agarwal.

          +  Deleted endnote discussing corner case with IKEv2 manual
             keying (identified as "to be removed before publication
             following SecDir review").

          +  Deleted Appendices D & E on why existing ingress & egress
             tunnelling behavour impede PCN and the endnotes that
             referred to them (identified as "to be removed before
             publication").

          +  Various minor corrections pointed out by reviewers.

Bob

Bob

At 14:30 02/08/2010, [email-masked] wrote:
><ftp://ftp.ietf.org/internet-drafts/draft-ietf-tsvwg-ecn-tunnel-09.txt>

________________________________________________________________
Bob Briscoe,                                BT Innovate & Design