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Liaison Statement: Liaison response on Y.flowreq

Submission Date: 2007-12-19
From: IETF TSV AREA (Lars Eggert)
To: ITU-T SG 13 (ITU-T SG 11 and SG 12 for information) (,,
Response Contact:
Technical Contact:
Purpose: In response
Attachments: (none)
The IESG and the IETF Transport and Internet Areas would like to thank
ITU-T SG 13 Question 4 for the notification of consent on the
"Requirements for the Support of Flow State Aware Transport Technology
in an NGN (Y.2121)". We appreciate that the ITU-T is cooperating with
the IETF when their Recommendations on Next Generation Networks
IETF standards.

As explained in our previous liaison response to ITU-T SG 13 dated
October 13, 2006, the requirements in Y.2121 (then Y.flowreq) propose
significant and fundamental changes to the Internet architecture and
several of its core protocols and mechanisms. These include new
congestion control methods, new authentication and authorization
procedures, new signaling schemes and new methods for routing and
traffic security.

The recently-published RFC 4775 [1] on "Procedures for Protocol
Extensions and Variations", which was created with considerable help
from ITU-T representatives, defines guideline procedures for
between the IETF and outside entities on the extension of IETF
protocols. It attempts to ensure that extensions will conform to the
applicable architectural principles and technical criteria. Any
development of protocol extensions and mechanisms to fullfil the
requirements in Y.2121 would clearly need to occur under the
of RFC 4775.

Following this liaison response to ITU-T SG 13, we had a very
constructive discussion with the proponents of flow-state aware
forwarding during the 67th IETF meeting in San Diego, CA, USA in
November 2006. During the meeting, we quickly reached a common
that development of protocol extensions to support Y.2121 will follow
the guidelines in RFC 4775. The proponents of flow-state-aware
forwarding agreed to bring their ideas to the IETF in the form of
Internet Drafts and perhaps presentations, so that they can be
by the full body of experts in the areas it covers.

We are pleased to note that following the face-to-face meeting at
IETF-67, a common mailing list ( was created, and
the proponents of flow-state aware forwarding discussed documenting
their ideas in an Internet Draft, with the eventual goal of requesting
"Birds-of-a-Feather (BOF)" session at an upcoming IETF, to present
proposals to the wider IETF community.

We continue to encourage this effort by the proponents of flow-state
aware forwarding and look forward to their Internet Drafts and
BOF request.

[1] S. Bradner, B. Carpenter and T. Narten. Procedures for Protocol
Extensions and Variations. Best Current Practice (BCP) 125, RFC 4775,
December 2006.