The IESG and the IETF Transport and Routing Areas would like to
thank ITU-T SG 13 Question 4 to bring our attention to its work on
"Requirements for the Support of Stateful Flow-Aware Transport
Technology in Next Generation Networks (Y.flowreq)". We appreciate
that the ITU-T is cooperating with the IETF when their Recommendations
on Next Generation Networks involve IETF standards.
We note that although Y.1221 itself was previously fully based on
existing IETF standards, Amendment 2 to Y.1221 from November 2005
and 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. We appreciate that you are bringing
these ideas to the IETF.
When extensions to IETF protocols are made within the IETF, the
normal IETF process includes IETF-wide expert review followed by
review and approval by the IESG. This process attempts to ensure
that extensions will conform to the applicable architectural
principles and technical criteria.
For extensions to IETF protocols proposed outside the IETF, the
IESG has recently approved draft-carpenter-protocol-extensions 
to be published as an RFC. This document, created with considerable
help from ITU-T representatives, defines guideline procedures for
cooperation between the IETF and outside entities on the extension
of IETF protocols. These guidelines are based on successful
interactions between the IETF and other SDOs, including ITU-T, in
diverse technical areas including IPv6, MPLS, GMPLS, NSIS, RSVP,
We recommend that these guidelines form the basis for the cooperation
between the IETF and ITU-T with regards to Y.flowreq and invite
those promoting flow-state-aware forwarding to bring their ideas
to the IETF in the form of Internet Drafts and perhaps presentations,
so that they can be discussed by the full body of experts in the
areas it covers. We are pleased that some proponents of flow-state-aware
forwarding have asked about the possibility of discussing the ideas
at the next IETF meeting. We encourage them to come and participate.
 S. Bradner, B. Carpenter and T. Narten. Procedures for protocol
extensions and variations. Internet Draft draft-carpenter-protocol-
extensions-04 (Work in Progress), October 2006.