Subject: [Sip] Publication request of draft-ietf-sip-fork-loop-fix

From: "DRAGE, Keith \(Keith\)" <[email-masked]>
Date: Tue, 8 Jul 2008 10:39:09 +0200

(As SIP WG cochair)

I have just requested publication of draft-ietf-sip-fork-loop-fix-07 as
a proposed standard.

The PROTO writeup follows:

PROTO writeup for
http://www.ietf.org/internet-drafts/draft-ietf-sip-fork-
loop-fix-07.txt: " Addressing an Amplification Vulnerability in 
Session Initiation Protocol (SIP) Forking Proxies"

   (1.a)  Who is the Document Shepherd for this document?  Has the
          Document Shepherd personally reviewed this version of the
          document and, in particular, does he or she believe this
          version is ready for forwarding to the IESG for publication?

Keith Drage

The document has been reviewed and is ready for forwarding to IESG for 
publication as a proposed standard.

   (1.b)  Has the document had adequate review both from key WG members
          and from key non-WG members?  Does the Document Shepherd have
          any concerns about the depth or breadth of the reviews that
          have been performed?

Document history:
*	draft-lawrence-maxforward-problems-00 was submitted 16th October
2005 
and expired 19th April 2006.
*	draft-ietf-sip-fork-loop-fix-00 was submitted 1st March 2006 and

expired on 1st September 2006.
*	draft-ietf-sip-fork-loop-fix-01 was submitted 4th April 2006 and

expired on 4th October 2006.
*	draft-ietf-sip-fork-loop-fix-02 was submitted 27th June 2006 and

expired on 27th December 2006.
*	draft-ietf-sip-fork-loop-fix-03 was submitted 7th September 2006
and 
expired on 7th March 2007.
*	draft-ietf-sip-fork-loop-fix-04 was submitted 21st October 2006
and 
expired on 24th April 2007.
*	draft-ietf-sip-fork-loop-fix-05 was submitted 7th March 2007 and

expired on 8th September 2007.
*	draft-ietf-sip-fork-loop-fix-06 was submitted on 3rd November
2007 and 
expired on 6th May 2008.
*	draft-ietf-sip-fork-loop-fix-07 was submitted on 3rd July 2008
and 
expires on 4th January 2009.

WGLC was initiated in the SIP WG on draft-ietf-sip-fork-loop-fix-01 on 
10th April 2006 with comments requested by 7th May 2006.

Review was made and comments were received from: Christer Holmberg,
Jonathan 
Rosenberg, Vijay Gurbani, Cullen Jennings, Jeroen van Bemmel,
Ravishankar 
Shiroor, Dale Worley, Scott Lawrence, Samir Srivastava, Peter Cordell, 
Thomas Froment, Juha Heinanen, Thomas Leseney, David Benoit, Kasturi 
Narayanan, Atul Kumar Jha, Theo Zourzouvillys, Paul Kyzivat, Dean
Willis, 
Michael Thomas, Eric Rescorla.

Key discussion issues have been:

*	Selection of a hash algorithm to be used. Section 4.2.3 of the 
document indicates the results of the discussion in this area.
*	Identification of a more optimal loop detection algorithm (see
draft-
campen-sipping-stack-loop-detect-00) which was not proceeded with, as 
it could not be shown to provide significant improvements for a 
standards track solution.

Some elements of the original proposal were split out in draft-sparks-
sipping-max-breadth-00 and draft-campen-sipping-stack-loop-detect-00.
There 
was also further input in draft-srivastava-sipping-loop-avoidance-00.
These 
documents have not been proceeded with.

The -05 version of the document was submitted to IESG on 2nd April 2007,
and 
was returned from IESG on 13th December 2007. SecDir review of the -05 
version submitted for publication uncovered a variation of the attack 
described in this document that was not reasonably mitigated with loop-
detection alone. The document went back to the working group and the
max-
breadth mechanism (draft-sparks-sipping-max-breadth-01), which was
already 
being discussed separately, was added to this document to address the 
identified risk.

WGLC was initiated in the SIP WG on draft-ietf-sip-fork-loop-fix-06 on
7th 
December 2007 with comments requested by 21st December 2007.

There was only one response to this WGLC and this was a late response
from 
Jan Kolomaznik.

   (1.c)  Does the Document Shepherd have concerns that the document
          needs more review from a particular or broader perspective,
          e.g., security, operational complexity, someone familiar with
          AAA, internationalization or XML?

The document defines mechanisms that are entirely internal to the
Session 
Initiation Protocol (SIP). The document shepherd considers that no
external 
review from an external specialist is necessary.

   (1.d)  Does the Document Shepherd have any specific concerns or
          issues with this document that the Responsible Area Director
          and/or the IESG should be aware of?  For example, perhaps he
          or she is uncomfortable with certain parts of the document, or
          has concerns whether there really is a need for it.  In any
          event, if the WG has discussed those issues and has indicated
          that it still wishes to advance the document, detail those
          concerns here.

The document provides a correction to the existing SIP protocol defined
in 
RFC 3261. The problem has been identified as part of the SIPit 
interoperability testing. The document shepherd has no concerns with the

document.

   (1.e)  How solid is the WG consensus behind this document?  Does it
          represent the strong concurrence of a few individuals, with
          others being silent, or does the WG as a whole understand and
          agree with it?

The proposal has had wide discussion in all aspects in the WG and key be

represented as having consensus amongst all key individuals.

   (1.f)  Has anyone threatened an appeal or otherwise indicated extreme
          discontent?  If so, please summarise the areas of conflict in
          separate email messages to the Responsible Area Director.  (It
          should be in a separate email because this questionnaire is
          entered into the ID Tracker.)

None indicated.

   (1.g)  Has the Document Shepherd personally verified that the
          document satisfies all ID nits?  (See
          http://www.ietf.org/ID-Checklist.html and
          http://tools.ietf.org/tools/idnits/).  Boilerplate checks are
          not enough; this check needs to be thorough.  Has the document
          met all formal review criteria it needs to, such as the MIB
          Doctor, media type and URI type reviews?

Normally SIP documents should conform to RFC 4485. However as this
document 
identifies a correction to RFC 3261, it does not need to follow those 
guidelines, but merely has to state the changed to RFC 3261.

There are no conformance issues with RFC 3427.

For ID-NITS the checks against idnits 2.08.10 report no NITS found.

   (1.h)  Has the document split its references into normative and
          informative?  Are there normative references to documents that
          are not ready for advancement or are otherwise in an unclear
          state?  If such normative references exist, what is the
          strategy for their completion?  Are there normative references
          that are downward references, as described in [RFC3967]?  If
          so, list these downward references to support the Area
          Director in the Last Call procedure for them [RFC3967].

The document has appropriately split its references into normative and 
informative references. All the normative references are now published 
standards track RFCs.

There is one informative reference (draft-ietf-sip-outbound) that is not
yet 
published.

   (1.i)  Has the Document Shepherd verified that the document IANA
          consideration section exists and is consistent with the body
          of the document?  If the document specifies protocol
          extensions, are reservations requested in appropriate IANA
          registries?  Are the IANA registries clearly identified?  If
          the document creates a new registry, does it define the
          proposed initial contents of the registry and an allocation
          procedure for future registrations?  Does it suggested a
          reasonable name for the new registry?  See
          [I-D.narten-iana-considerations-rfc2434bis].  If the document
          describes an Expert Review process has Shepherd conferred with
          the Responsible Area Director so that the IESG can appoint the
          needed Expert during the IESG Evaluation?

The document defines one new header field, and one new response code.
The 
process for adding these is defined in RFC 3427 and those requirements
have 
been completed with. The IANA registrations have been verified to be in 
conformance with the existing IANA registries.

   (1.j)  Has the Document Shepherd verified that sections of the
          document that are written in a formal language, such as XML
          code, BNF rules, MIB definitions, etc., validate correctly in
          an automated checker?

The document defines a Max-Breadth header field, defined using ABNF.
This is 
trivial and has been verified to be correct by inspection only. 

   (1.k)  The IESG approval announcement includes a Document
          Announcement Write-Up.  Please provide such a Document
          Announcement Writeup?  Recent examples can be found in the
          "Action" announcements for approved documents.  The approval
          announcement contains the following sections:

Technical Summary

This document normatively updates RFC 3261, the Session Initiation
Protocol 
(SIP), to address a security vulnerability identified in SIP proxy
behavior.  
This vulnerability enables an attack against SIP networks where a small 
number of legitimate, even authorized, SIP requests can stimulate
massive 
amounts of proxy-to-proxy traffic.

This document strengthens loop-detection requirements on SIP proxies
when 
they fork requests (that is, forward a request to more than one
destination).  
It also corrects and clarifies the description of the loop-detection 
algorithm such proxies are required to implement. Additionally, this 
document defines a Max-Breadth mechanism for limiting the number of 
concurrent branches pursued for any given request.

Working Group Summary

The document was produced by the SIP working group. There is consensus
in 
the WG to publish this document.

Document Quality

The document has been produced as a result of an issue identified during

SIPit interoperability testing.

Personnel

Keith Drage is the document shepherd for this document. Cullen Jennings
is 
the responsible Area Director. The IANA Expert(s) for the registries in
this 
document are <TO BE ADDED BY THE AD>.
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