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Network Working Group L. Andersson, Ed. Request for Comments: 4929 Acreo AB BCP: 129 A. Farrel, Ed. Category: Best Current Practice Old Dog Consulting

                                                             June 2007
    Change Process for Multiprotocol Label Switching (MPLS) and
         Generalized MPLS (GMPLS) Protocols and Procedures

Status of This Memo

 This document specifies an Internet Best Current Practices for the
 Internet Community, and requests discussion and suggestions for
 improvements.  Distribution of this memo is unlimited.

Copyright Notice

 Copyright (C) The IETF Trust (2007).

Abstract

 This document provides guidelines for applying or extending the MPLS
 or GMPLS ((G)MPLS) protocol suites and clarifies the IETF's (G)MPLS
 working groups' responsibility for the (G)MPLS protocols.  This
 document is directed to multi-vendor fora and Standards Development
 Organizations (SDOs) to provide an understanding of (G)MPLS work in
 the IETF and documents the requisite use of IETF review procedures
 when considering (G)MPLS applications or protocol extensions in their
 work.  This document does not modify IETF processes.

Andersson & Farrel Best Current Practice [Page 1] RFC 4929 MPLS and GMPLS Change Process June 2007

Table of Contents

 1. Introduction ....................................................3
    1.1. Document Source ............................................4
    1.2. Conventions Used in This Document ..........................4
 2. Overview of (G)MPLS within the IETF .............................4
    2.1. IETF Working Groups Developing (G)MPLS Technology ..........5
         2.1.1. Multiprotocol Label Switching Working Group .........5
         2.1.2. Common Control & Measurement Plane Working Group ....5
         2.1.3. MPLS and CCAMP Division of Work .....................6
    2.2. Other (G)MPLS Technology-Related Working Groups ............6
    2.3. Organizations Outside the IETF .............................7
 3. Overview of (G)MPLS Change Process ..............................8
 4. MPLS and GMPLS Change Process ...................................9
    4.1. Flow Diagram ..............................................10
    4.2. Description of Process Stages .............................11
         4.2.1. Preliminary Investigation ..........................12
         4.2.2. Requirements Statement Evaluation ..................13
         4.2.3. Working Group Procedures ...........................14
         4.2.4. REWG Evaluation of the Requirements Statement I-D ..14
         4.2.5. AD Evaluation of Completed Requirements
                Statement I-D ......................................14
         4.2.6. IESG review of Requirements Statement I-D
                and PSWG Charter ...................................15
         4.2.7. Solutions Work .....................................15
 5. Rejecting the Requirements Statements I-D ......................16
    5.1. Reasons for Rejection .....................................16
    5.2. Actions Required When Rejecting Requirements
         Statement I-Ds ............................................18
    5.3. Appeals ...................................................18
 6. Abandonment of the Solutions I-D ...............................19
    6.1. Appeals ...................................................19
 7. (G)MPLS Integrity and Ownership ................................19
 8. Security Considerations ........................................20
 9. Acknowledgements ...............................................20
 10. IANA Considerations ...........................................21
 11. References ....................................................21
    11.1. Normative References .....................................21
    11.2. Informative References ...................................21

Andersson & Farrel Best Current Practice [Page 2] RFC 4929 MPLS and GMPLS Change Process June 2007

1. Introduction

 The MPLS and GMPLS technology is developed in two main tracks in the
 IETF.  "MPLS" refers to the work done for packet switched networks,
 while "GMPLS" refers to the efforts to apply the MPLS protocols to
 all types of networks including packet and non-packet technologies.
 Though GMPLS by definition is a superset of MPLS, the term "(G)MPLS"
 is used in this document to indicate both of these tracks.  A
 terminology section that covers the use of terms and concepts used in
 this document is found in Section 2.6.
 [RFC4775] discusses procedural issues related to the extension or
 variation of IETF protocols by other SDOs.  It provides the
 guidelines and procedures to be used by other SDOs when considering
 the requirements for extensions to IETF protocols.  [RFC4775]
 recommends that major extensions to, or variations of, IETF protocols
 only take place through normal IETF processes or in coordination with
 the IETF.
 The (G)MPLS protocol families were developed within the IETF and
 constitute significant protocol suites within the Internet standards.
 The (G)MPLS suites of protocols have become popular for a number of
 new applications and deployment scenarios.  There have been concerns
 with regards to other technology fora developing, using, and
 publishing non-standard protocol extensions as a standard not only
 for use within their community, also for wider use by the industry.
 Especially concerning is the development of extensions, without
 consulting the (G)MPLS working groups, which are in conflict with
 efforts on-going in the (G)MPLS working groups, and then presented to
 the (G)MPLS working group as 'fait accompli'.
 The definition and publishing of non-standard extensions by other
 fora, without IETF review, and outside of the IETF publication
 process, regardless if rationalized as limited to use among fora
 vendors, or limited to a particular application, or rationalized as
 allowing timely demos, has the unfortunate potential to hinder
 interoperability and increase complexity of the protocol, sows
 confusion in the industry, and circumvents the Internet standards
 process that exists to ensure protocol implementability.  As
 described in [RFC4775], non-standard extensions, including
 experimental values, are not to be portrayed as industrial standards
 whether by an individual vendor, an industry forum, or a standards
 body.
 This document clarifies the IETF's MPLS and Common Control and
 Measurement Plane (CCAMP) working groups' roles and responsibilities
 for the (G)MPLS protocols and documents the requisite use of, and how

Andersson & Farrel Best Current Practice [Page 3] RFC 4929 MPLS and GMPLS Change Process June 2007

 to apply, the [RFC4775] procedure of using the IETF review processes,
 [RFC2026] and [RFC2418], for fora wishing to apply or extend the
 (G)MPLS protocols.  Use of the IETF review processes will ensure an
 open process for protocol development and ensure a non-harmful
 evolution for these IETF protocols, which will benefit the larger
 industry users' community.  IETF itself cannot enforce a forum to use
 the (G)MPLS change procedure, though any forum not following it, when
 applying for IANA assignment or IETF publication, will be delayed
 until this procedure has been completed.
 This document does not change the formal IETF standards process as
 defined in [RFC2026] and [RFC2418].  It is consistent with the
 general procedures for protocol extensions defined in [RFC4775] and
 shows how they are applied in the case of (G)MPLS.  Any procedures
 described in this document are to be implemented in a way consistent
 with these three documents.  They MUST be used when other SDOs and
 fora wish to propose (G)MPLS changes.  They SHOULD be used internally
 within the IETF unless the changes concerned are considered non-
 controversial by the responsible Area Director(s) (e.g., covered by
 the working group charter), in which case other aspects of the normal
 IETF standards process cover the necessary procedures.

1.1. Document Source

 This document is the joint work of the IETF Routing Area Directors,
 the IETF MPLS and CCAMP Working Group Chairs, and the IETF's liaisons
 to the ITU-T.  It had considerable review and comment from key
 members of the ITU-T who have given their time and opinions based on
 experience for which the authors are grateful.  The IESG has also
 provided valuable input to arrive at the process documented here.
 The acknowledgements section lists those whose contributions have
 been particularly helpful.

1.2. Conventions Used in This Document

 Although this document is not a protocol definition, the key words
 "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
 "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document
 are to be interpreted as described in RFC 2119 [RFC2119].  This usage
 is chosen to make the steps and procedures completely clear.

2. Overview of (G)MPLS within the IETF

 This section describes the key IETF working groups developing the
 (G)MPLS technology and provides information on IETF working groups
 using the (G)MPLS technology.

Andersson & Farrel Best Current Practice [Page 4] RFC 4929 MPLS and GMPLS Change Process June 2007

 It should be remembered that the IETF environment is highly dynamic.
 Working groups and whole areas come and go.  The overview of the
 relevant working groups within the IETF is only a snapshot in time.

2.1. IETF Working Groups Developing (G)MPLS Technology

 Two working groups in the IETF's Routing Area are responsible for
 work related to developing the (G)MPLS technologies:  Multiprotocol
 Label Switching (MPLS) working group and the Common Control and
 Measurement Plane (CCAMP) working group.
 The following sections provide brief overviews of the chartered work
 of these two IETF working groups.

2.1.1. Multiprotocol Label Switching Working Group

 The Multiprotocol Label Switching (MPLS) working group is responsible
 for standardizing the base technology that uses label switching, and
 for describing the implementation of Label Switched Paths (LSPs) over
 various packet and frame-based link level technologies.  The working
 group charter includes procedures and protocols for the distribution
 of labels between routers, as well as encapsulations, operation and
 management, traffic engineering, and multicast considerations.
 This document assumes that the MPLS working group remains the
 chartered authority on MPLS technologies, but notes that the IETF may
 appoint another working group (refer to [RFC2418]) to handle specific
 extensions or changes to the protocols.  Further, in the event that
 the MPLS working group completes its work and is closed, the IETF
 will use the non-working group standards track document process
 (described in [RFC2026]) using designated experts from the community
 [RFC2434] for the MPLS protocols.

2.1.2. Common Control & Measurement Plane Working Group

 The IETF Common Control and Measurement Plane (CCAMP) working group
 coordinates the work within the IETF defining common control and
 measurement planes for ISP and SP core tunneling technologies.  This
 includes, but is not limited to, defining signaling protocols and
 measurement protocols such that they support multiple physical path
 and tunnel technologies using input from technology-specific working
 groups such as the MPLS working group.  It also includes the
 development of protocol-independent metrics and parameters for
 describing links and paths that can be carried in protocols.
 The technology that the CCAMP working group focuses on is called
 Generalized MPLS (GMPLS), indicating that CCAMP addresses a
 generalized technology, where labels are defined in such a way that

Andersson & Farrel Best Current Practice [Page 5] RFC 4929 MPLS and GMPLS Change Process June 2007

 they will be compatible with the technology over which the data is
 transported.  While the MPLS working group focuses on packet- and
 frame-switched technologies, the CCAMP working group work focuses on
 common methods across a broad spectrum of switching technologies
 including packet and frame technologies.  In this respect, GMPLS can
 be viewed as a superset of MPLS.
 The procedures in this document assume that the CCAMP working group
 remains the authority on GMPLS technologies, but acknowledges that
 the IETF may appoint another working group (refer to [RFC2418]) to
 handle specific extensions or changes to the protocols.  Further, in
 the event that the CCAMP working group completes its work and is
 closed, the IETF will use the non-working group standards track
 document process (described in [RFC2026]) using designated experts
 from the community [RFC2434] for the GMPLS protocols.

2.1.3. MPLS and CCAMP Division of Work

 From time to time, the MPLS and CCAMP working groups decide to divide
 work between themselves in a way that does not strictly follow the
 split between the working groups as defined in the working group
 charters.  This is the case, e.g., for P2MP TE LSPs, where the MPLS
 working group is specifying requirements and base technology for all
 of the (G)MPLS technologies.
 An entity or individual that wishes to propose extensions or changes
 to (G)MPLS should first decide to which working group (MPLS or CCAMP)
 it will bring the proposal.  However, the MPLS and CCAMP working
 group chairs, in conjunction with their Area Directors, may redirect
 the proposal to another working group.

2.2. Other (G)MPLS Technology-Related Working Groups

 Problem statements and requirements for (G)MPLS technology have been
 produced by several working groups in addition to the MPLS and CCAMP
 working groups.  IETF working groups are defined for the management
 of specific tasks by their charter.  Their charter defines their
 role, relationship with other working groups, and the applicable
 procedures to follow when extensions to (G)MPLS may be needed.  This
 section provides an overview of the (G)MPLS-related groups and their
 responsibilities.  Additional information describing the working
 groups and their charters is available on the IETF web pages.
 The IP over Optical (IPO) working group and the Internet Traffic
 Engineering working group (TEWG) are examples of working groups which
 focus on problem statements and requirements for (G)MPLS to be
 considered by the (G)MPLS working groups.  These working groups have
 not specified any protocols.

Andersson & Farrel Best Current Practice [Page 6] RFC 4929 MPLS and GMPLS Change Process June 2007

 The Bidirectional Forwarding Detection (BFD) working group, also may
 use the (G)MPLS protocols and mechanisms.  The BFD working group is
 chartered for requirements evaluation and protocol specification
 related to BFD.  If the working group needs to extend or change the
 (G)MPLS protocols, the procedures specified by its charter and the
 IETF's standard processes are applicable.
 The Layer 2 VPN (L2VPN) and Layer 3 VPN (L3VPN) working groups have
 been chartered to specify a limited number of solutions for Provider
 Provisioned VPNs.  Both working groups are in the Internet Area.
 Much of the work of the L2VPN and L3VPN working groups does not
 include specifying new protocols or extensions to existing protocols.
 Where extensions are needed, the procedures as specified by their
 charters and the IETF's standard processes are applicable.
 The Layer 1 VPN (L1VPN) working group is chartered to specify
 mechanisms necessary for providing Layer 1 VPN services
 (establishment of layer 1 connections between CE devices) over a
 GMPLS-enabled transport service-provider network.  Protocol
 extensions required for L1VPN will be done in cooperation with MPLS,
 CCAMP, OSPF, IS-IS, IDR, L3VPN, and other WGs where necessary.  That
 is, the L1VPN working group will not develop GMPLS protocol
 extensions in isolation, but will develop requirements and propose
 extensions that will be reviewed and approved by the (G)MPLS working
 groups.
 The Pseudo Wire Emulation End to End (PWE3) working group is a
 working group that may use the (G)MPLS protocols in its
 specifications.  Should the PWE3 specifications require extension or
 changes to the (G)MPLS protocols, the procedures as specified by its
 charter and the IETF's standard processes are applicable.

2.3. Organizations Outside the IETF

 A number of standards development organizations (SDOs) and industrial
 forums use or reference the (G)MPLS protocols in their
 specifications.  Some of these organizations have formal or informal
 liaison relationships with the IETF [RFC4052].  The IETF exchanges
 information with these organizations about what is happening on both
 sides, including plans and schedules, using liaison statements
 [RFC4053].  More details about the cooperation relationship between
 the IETF and the ITU-T can be found in [RFC3356].
 The procedures in this document are applicable to all organizations
 outside the IETF whether or not they have formal liaison
 relationships with the IETF.  If any organization outside the IETF
 has a requirement for extensions or modifications to the (G)MPLS
 protocols then the procedures in this document apply.

Andersson & Farrel Best Current Practice [Page 7] RFC 4929 MPLS and GMPLS Change Process June 2007

3. Overview of (G)MPLS Change Process

 This is a non-normative section, as it is intended to provide a high-
 level view of [RFC4775] procedures for protocol extensions.
 Application of these procedures for (G)MPLS are defined in detail in
 Section 4.
 Whenever there is reason to believe that a particular problem may be
 solved by use of or extensions to the (G)MPLS protocols, a
 communication using the formal liaison process, or, for a forum
 without a formal relationship, an informal communication, may be used
 to discuss the problem with the IETF ([RFC4052] and [RFC4053]).
 Collaboration with the IETF in the early discussion phase will
 facilitate a timely understanding of whether the problem has already
 been solved, may be outside the scope of the (G)MPLS protocols, or
 may require more investigation.
 Whenever any extension or change to the (G)MPLS protocols is desired,
 a problem statement and/or requirements statement must be produced
 and must be submitted to IETF as an Internet-Draft.  When the
 requirements come from an external organization, informal
 communications, such as e-mail to working group mailing lists, is
 strongly encouraged as it facilitates timely and cooperative work.
 However, if desired, the Internet-Draft, containing the
 requirement(s), may be submitted to the working group using a formal
 liaison statement.  IETF's response to the request will be given as a
 reply to the liaison.  This use of formal communication reduces the
 risk of confusing an individual participant's opinion for that of the
 group as can happen on mailing lists, though it does introduce a more
 lengthy communication cycle.  If there is no formal liaison
 relationship, a communication may be sent directly to the (G)MPLS
 working group, a relevant Area Director, or the IESG.
 The IETF, through the appropriate Area Director, and the chairs of
 the MPLS and CCAMP working groups for (G)MPLS related work, will
 direct the requirements draft to an appropriate working group for
 assessment and comment.  This process may require communication and
 discussion for clarification, but the IETF undertakes to perform the
 assessment in a timely manner.
 In assessing the requirements statement I-D, the IETF may determine:
  1. that the requirements can be satisfied without modifications to the

(G)MPLS protocols

Andersson & Farrel Best Current Practice [Page 8] RFC 4929 MPLS and GMPLS Change Process June 2007

  1. that the requirements are not sufficiently general or there is not

sufficient interest to do a standards-track solution to warrant a

   Standards-track change to the (G)MPLS protocols
  1. that the requirements justify a standards-track change to the

(G)MPLS protocols

  1. that the requirements might not be possible to satisfy without

violating the (G)MPLS architecture in a way that would harm the

   (G)MPLS technology
  1. that the requirements should be combined with other requirements to

solve a more general problem or solve the same problem in a more

   flexible way.
 In the event that the IETF agrees to develop a solution, the IETF
 will set milestones that would result in timely delivery of the
 solution in a timely manner.  If the IETF rejects the requirements,
 this will only be done with clear explanation and full discussion
 with the source of the requirements.
 The solutions that are developed within the IETF may be sourced from
 external organizations and presented for review, discussion,
 modification, and adoption as Internet-Drafts.  Such solutions drafts
 may be presented to the IETF in advance of the completion of the
 requirements work, but all solutions will be processed through the
 normal IETF process with other proposed solutions.  Solution drafts
 are adopted as an IETF working group draft when the requirements are
 stable, and not before the protocol-responsible working group has a
 charter item to cover the solutions work.  It is strongly recommended
 for interested parties to start informal discussion in the IETF, as
 early as possible, and to co-author in the IETF's work.  It is not
 recommended for the source forum to continue to work on solutions in
 parallel with on-going work in the IETF.  If the protocol-responsible
 working group is unable to accept the work (e.g., due to current work
 load), the IETF processes ([RFC2418]) provide alternate options for
 ensuring the work is completed.

4. MPLS and GMPLS Change Process

 This section defines the (G)MPLS change process and the rules that
 must be followed in order to make extensions or changes to the
 (G)MPLS protocols.  The language of [RFC2119] is used in order to
 clarify the required behavior of the IETF and the originator of the
 change request.  It is consistent with the general procedures for
 protocol extensions defined in [RFC4775].  Any interpretation of
 procedures described in this document and their implementation are to
 be in a way consistent with [RFC4775].

Andersson & Farrel Best Current Practice [Page 9] RFC 4929 MPLS and GMPLS Change Process June 2007

 Anyone who intends to use one of the existing (G)MPLS protocols, but
 thinks that it will not satisfy their needs MUST use the procedures
 described in this document.  They SHOULD be used internally within
 the IETF unless the changes concerned are considered non-
 controversial by the responsible Area Director(s) (e.g., covered by
 the working group charter), in which case other aspects of the normal
 IETF standards process apply.  Changes or extensions to the (G)MPLS
 protocols MUST NOT be made by any other mechanism.  The IETF MUST NOT
 endorse any publications (including RFCs, whether on the Standards
 Track, Informational, or Experimental) that change or extend the
 (G)MPLS protocols except for those that arise through the correct
 execution of the procedures in this document.  The IETF MUST NOT
 endorse any IANA action that allocates (G)MPLS protocol codepoints,
 except as a result of actions arising from the correct execution of
 the procedures in this document.

4.1. Flow Diagram

 Figure 1 gives a visual overview to illustrate the roles of a (G)MPLS
 requirements evaluation working group (REWG) and (G)MPLS protocol
 solutions working group (PSWG).  The figure presents two alternatives
 for a requestor: (1) contact the IETF early in the problem definition
 phase (preliminary investigation), or, (2) later, with a requirements
 statement.  The figure is for illustration only; it does not contain
 all of the possible interactions and IETF procedure alternatives.
 The text in the subsequent sections describes the process.

Andersson & Farrel Best Current Practice [Page 10] RFC 4929 MPLS and GMPLS Change Process June 2007

   Start                     +-------------+
     |                       |optional     |
     +--<--------------------|preliminary  |<-------Start
     |                       |investigation|
     V                       +-------------+
 +------------+            +---------+              +---------+
 |requirements| discussion |review by|     YES      |  IESG   | YES
 |statement   |----------->|WG chairs|------------->|decision |------+
 |I-D         | on mailing |and ADs  | request to   |         |      |
 +------------+   list     +---------+ IESG to      +---------+      |
                            |          appoint REWG   |              |
                            |NO        and charter    |NO        REWG|
                            V          req eval       |     chartered|
                     +-------------+                  |    to work on|
                     |response     |                  |  requirements|
                     |to the       |                  |     statement|
                     |requirements |<-----------------+              |
                  +->|statement    |<----------------+               |
                  |  +-------------+                 |               |
                  |      ^                           |               |
                NO|      |     NO                    |               |
                  |      +-----------------+         |               V
                  |                        |         |  NO    +------+
              +--------+                +-------+    +--------| REWG |
              | IESG/  |        YES     |  AD   |             |  req |
  +-----------|decision|<---------------|review |<------------| eval |
  |PSWG       |        |   request to   |       |     YES     |      |
  |chartered  +--------+   IESG to      +-------+             +------+
  |to work                 approve I-D
  |                        and charter
  |                        PSWG (if needed)
  |          +---------+
  |          | IETF    |             +-----+
  +--------->|  PSWG   |-----/ /---->| RFC |
       +---->| process |             +-----+
       |     +---------+
   solutions
      I-D
                   Figure 1: Change Process Overview

4.2. Description of Process Stages

 This section describes how the (G)MPLS change process works, what is
 expected from individuals or organizations that want to extend or
 change the (G)MPLS protocols, and the responsibilities of the IETF.

Andersson & Farrel Best Current Practice [Page 11] RFC 4929 MPLS and GMPLS Change Process June 2007

4.2.1. Preliminary Investigation

 This step is OPTIONAL, and is intended to provide a lightweight way
 to "feel out" the IETF's position on a proposal without going to the
 effort of writing an Internet-Draft.  The intention is to determine
 whether the problem has been examined already, whether the problem is
 in scope for the IETF, and whether solutions are already known.
 Although the preliminary investigation phase is optional it is
 RECOMMENDED that the originator of any requirements consult and
 discuss the issues concerned as early as possible to avoid any wasted
 effort, and the preliminary investigation phase provides a mechanism
 to do this.
 Useful discussions may be held at this stage in order to ensure that
 the problem statement and requirements statement Internet-Drafts
 contain the right material.  This step is described as lightweight
 because no Internet-Draft is required and because the step largely
 involves offline discussions.  However, it may be the case that this
 step involves considerable technical discussions and may, in fact,
 involve an extensive, substantive exchange of ideas and opinions.
 This step SHOULD be carried out informally on the mailing list of the
 REWG or on the Routing Area discussion mailing list, and MAY be
 initiated by any individual, group of individuals, external
 organization, or IETF working group.
 When an external SDO has a liaison relationship with the IETF, it MAY
 carry out this step using a formal liaison.  The liaison SHOULD be
 sent to the designated liaison manager who is responsible for
 forwarding them to the IESG who will assign a Responsible AD.  The
 initiators of the liaison SHOULD make themselves available for
 discussion on the selected mailing list.  If a formal liaison is
 used, the IETF will respond using the procedures of [RFC4053].
 At this stage, a problem statement I-D MAY be produced to help
 further the discussions and to clarify the issues being addressed.
 A possible outcome of this preliminary investigation is that the
 requirements and problem are understood, but agreed to be out of
 scope for the IETF.  Alternatively, it may be that the problem can be
 solved with existing protocols.  The full list of outcomes from the
 preliminary investigation phase are similar to those for the
 requirements statement evaluation phase described in Section 4.2.2,
 but the requirements statement evaluation phase that allows wider
 IETF community participation in developing a complete requirement set
 MUST form part of the process if the IETF is to consider to develop
 protocol solutions.  The process cannot move direct from the

Andersson & Farrel Best Current Practice [Page 12] RFC 4929 MPLS and GMPLS Change Process June 2007

 preliminary investigation phase to the development of solutions
 unless the working group agrees (e.g., the problem is minor).

4.2.2. Requirements Statement Evaluation

 Before the IETF can formally pronounce on requests to change or
 extend the (G)MPLS protocols, a requirements statement I-D MUST be
 written per [RFC2026].
 The requirements statement I-D MUST be introduced by the authors to
 the IETF through an email to the REWG mailing list, to the Routing
 Area discussion mailing list, or by a formal liaison from an external
 SDO which will result in the IETF introducing the requirements
 statement I-D to the REWG mailing list.  If the requirements
 statement I-D is brought to the IETF through a formal liaison, the
 initiators of the liaison SHOULD make themselves available for
 discussion on the designated IETF mailing lists.
 After discussion on the IETF mailing lists, the responsible Area
 Director MUST decide whether the requirements will be formally
 evaluated by the IETF, and MUST deliver a response to the per
 [RFC4053] and [RFC4775].  If a formal liaison was not used, the
 response SHOULD be delivered to the appropriate contact as listed on
 the communication.
 The IETF response MUST be sufficiently explanatory to inform the
 requesting organization of what, if anything, the IETF has decided to
 do in response to the request.  The following list is provided to
 illustrate possible responses:
 a.  Requirements not understood.  Further discussion is required.
 b.  Requirements understood, but judged to be out of scope for the
     IETF.  In this case, the originator of the requirements can work
     on requirements and solutions and will not be impeded by the
     IETF.  The IETF may request to be kept informed of progress.
 c.  Requirements understood, but no protocol extensions are needed.
     It may be desirable for the external SDO to cooperate with the an
     IETF working group in the production of an Applicability
     Statement Internet-Draft.
 d.  Requirements understood, and the IETF would like to develop
     protocol extensions.  This results in execution of the rest of
     the procedure, described below.  The requirements raised in the
     requirements statement I-D may be combined with other
     requirements to produce more general extensions or changes to the
     (G)MPLS protocols.

Andersson & Farrel Best Current Practice [Page 13] RFC 4929 MPLS and GMPLS Change Process June 2007

4.2.3. Working Group Procedures

 In many cases, the problem covered by the requirements statement I-D
 will fall within the scope of the existing charter of a working
 group.  In this case, the responsible Area Directors will designate
 the working group as the REWG and pass the requirements statement I-D
 to the working group for evaluation.  If the problem is not covered
 by an existing charter, other alternatives (refer to [RFC2418]) may
 be used, e.g., rechartering, BOF, chartering a new working group.
 If the IETF modifies its prior decision to accept the work, the IETF
 MUST communicate this to the requestor in a timely manner.

4.2.4. REWG Evaluation of the Requirements Statement I-D

 The objective of the REWG evaluation process is to determine a clear
 and complete statement of the requirements for changes or extensions
 to the (G)MPLS protocols.  This will necessitate normal IETF working
 group procedures in the REWG and MAY include the generation of
 revisions of the requirements statement I-D in cooperation between
 the members of the REWG and the original authors of the requirements
 statement I-D.
 The originators of the requirements statement I-D MUST make
 themselves available to discuss the work on the REWG mailing list.
 If this does not happen, the chairs of the REWG MAY determine that
 there is insufficient support for the work and MAY reject the
 requirements statement I-D.
 The output of the REWG will be either:
  1. a completed requirements statement I-D that has been accepted by

working group consensus within the REWG and has passed through

   working group last call;
 or
  1. a rejection of the requirements using the response procedure as

described in Section 5.

4.2.5. AD Evaluation of Completed Requirements Statement I-D

 As with all Internet-Drafts produced by a working group, the ADs will
 review the completed requirements statement I-D produced by the REWG.
 The ADs will then pass the document to the IESG for review.  If
 charter changes are needed or a new PSWG needed, the appropriate
 process will be followed.

Andersson & Farrel Best Current Practice [Page 14] RFC 4929 MPLS and GMPLS Change Process June 2007

4.2.6. IESG review of Requirements Statement I-D and PSWG Charter

 As with all Internet-Drafts, the IESG will review and make a decision
 on the progression of the requirements statement I-D.
 If the IESG rejects the requirements statement I-D, it will generate
 an appropriate response to the working group (and, if needed, to the
 originator of the request).
 The IESG will review any proposed charter changes for the PSWG or, if
 needed, consider alternatives.  This might include the formation of a
 new working group specifically to work on the solutions.

4.2.7. Solutions Work

 The appropriate PSWG will start work on solutions following the
 normal IETF process.
 Solutions I-Ds MAY be prepared externally (such as within an external
 organization) or within the IETF, submitted to the IETF for draft
 publication using the procedures of [RFC2418], and introduced to the
 PSWG for consideration.  Such I-Ds MAY be submitted at earlier stages
 in the process to assist the REWG in its development and discussion
 of the requirements, but no I-D will be formally considered as a
 solutions I-D until the PSWG has a charter item that covers the work
 and the REWG chairs are confident that the requirements are stable.
 The IETF makes no guarantees that an externally produced solutions
 I-D will form the basis of the PSWG solutions I-D, but the PSWG MUST
 consider such an I-D for review and revision as a possible solution
 I-D, using the same open procedures ([RFC2418]) as for any individual
 submission.  The IETF's procedures are based on open and fair
 participation, and thorough consideration of technical alternatives.
 Interested parties (both implementers and users) of the SDO
 originating the request are strongly encouraged to participate in the
 PSWG to ensure appropriate interest is shown in the solutions work
 and to provide timely solutions development.  The IETF's work, as
 that of any SDO, is driven by its participants.  The IETF is an open
 community and any SDO requesting IETF solutions work SHOULD ensure
 appropriate industry interest in the work, or the IETF MAY
 discontinue its support of the work.  Appropriate communication of
 the discontinued work will be made to the originator of the request
 (if the originator is reachable).
 The final development of the solutions I-D is subject to the normal
 working group review, consensus, and last call within the PSWG.

Andersson & Farrel Best Current Practice [Page 15] RFC 4929 MPLS and GMPLS Change Process June 2007

 Where the requirements originated from an external organization, the
 PSWG SHOULD regularly communicate its progress using a formal liaison
 process if one exists.  This communication SHOULD also be used to
 request review input and comment on the development of the solutions
 I-D.  The solutions I-D MUST be communicated to the originating
 organization during working group last call for final review against
 the requirements.  When the solutions I-D is complete (normally upon
 completing working group last call and/or on entering the RFC
 Editor's queue) the PSWG MUST inform the originating organization of
 the completed solution.

5. Rejecting the Requirements Statements I-D

 Rejection of the requirements statements is a sensitive matter for
 the authors of the requirements and MUST be handled with full
 disclosure and explanation by the IETF.  All working group actions
 are taken in a public forum ([RFC2418]).
 The requirements can be rejected at various stages of the process as
 described in the previous sections.  The person or group that makes
 the rejection is responsible for generating an explanation of the
 rejection and MUST follow the [RFC4775] process.  Possible reasons
 for rejection are described in this section.

5.1. Reasons for Rejection

 The requirements statement I-D can only be rejected with full
 disclosure by the IETF.  Possible reasons for rejection and possible
 next steps as described here.
  1. Requirements not understood. Either during preliminary

investigation or during evaluation of the requirements statement

   I-D, it was not clear what the requirements are, or what the
   problem being addressed is.
   This rejection forms part of an on-going communication and it is
   expected that the process will continue with further iterations.
  1. Out of scope for the IETF. Many stages of this process may

determine that the requirements are out of scope for the IETF. In

   this case, the IETF MUST NOT constrain the authors of the
   requirements statement I-D from working on a solution.  If any
   (G)MPLS changes are later identified, the requestor MUST reinitiate
   the (G)MPLS change procedure.
  1. No protocols extensions or changes are needed. At some stage in

the evaluation of the requirements it may become clear that they

   can all be met through appropriate use of existing protocols.  In

Andersson & Farrel Best Current Practice [Page 16] RFC 4929 MPLS and GMPLS Change Process June 2007

   this case, no further evaluation of the requirements is required,
   but the REWG MUST explain how the protocols can be used to meet the
   requirements and MAY cooperate with the authors of the requirements
   statement I-D in the production of an Applicability Statement
   Internet-Draft or a Profiles Internet-Draft that explains precisely
   how the existing protocols can be used to meet the requirements.
  1. Insufficient support within the IETF. Although the work described

within the requirements statement I-D is within scope for the IETF,

   and despite the support of the originators of the requirements
   statement I-D on the REWG mailing list, the chairs of the REWG have
   determined that there is insufficient support in the REWG to
   complete requirements statement I-D and initiate solutions work in
   the PSWG.  In this case, the IETF MUST NOT restrict the authors of
   the requirements statement I-D from working on a solution.  The
   solution (and/or IANA codepoints requested) SHALL be presented to
   the IETF's (G)MPLS PSWG for review and possible publication as an
   Informational or Experimental RFC, and, pending IETF review
   results, the IETF SHALL NOT block applications to IANA for
   codepoints.  If IANA codepoint assignments are required, the IANA
   Requirements prescribed for those assignments in the relevant RFCs
   MUST be satisfied.  It is highly recommended for the SDO to
   encourage its participants to participate in the IETF work to
   ensure appropriate industry representation in the work.
  1. Insufficient support for the work from the original requesters. If

the authors of the requirements statement I-D do not make

   themselves available on the REWG mailing list for discussion of the
   requirements or do not contribute the completion of the
   requirements statement I-D, the chairs of the REWG MAY determine
   that there is insufficient support for the work and MAY reject the
   requirements statement I-D.  In this case, the IETF MUST NOT grant
   permission for the work to be carried out in any other
   organization, and MUST NOT endorse the publication of any changes
   or extensions to the (G)MPLS protocols and MUST NOT instruct IANA
   to allocate any codepoints.  The requirements may be reintroduced
   by starting the procedure again from the top.
  1. Satisfying the requirements would break the technology. It is

possible that an assessment will be made that, although the

   requirements are reasonable, it is not possible to satisfy them
   through extensions or changes to the (G)MPLS protocols without
   violating the (G)MPLS architecture in such a way as would break the
   (G)MPLS technology.  In this case, a recommendation will be made
   that some other technology be used to satisfy the requirements.
   See Section 7 for further discussions of the protection of the
   integrity of the (G)MPLS technology.  In this case, the IETF MUST
   NOT grant permission for the work to be carried out in any other

Andersson & Farrel Best Current Practice [Page 17] RFC 4929 MPLS and GMPLS Change Process June 2007

   organization, and MUST NOT endorse the publication of any changes
   or extensions to the (G)MPLS protocols and MUST NOT instruct IANA
   to allocate any codepoints.

5.2. Actions Required When Rejecting Requirements Statement I-Ds

 Upon rejection, the IETF MUST make a clear statement of why the
 requirements statement I-D has been rejected and what next step
 actions are acceptable (refer to Section 5.1).
 The communication of the rejection depends on the form of the
 original submission as follows.
  1. If the requirements are brought to the IETF as a preliminary

investigation (see Section 4.2.1) through an email exchange then

   the response MUST be made as an email response copied to an IETF
   mailing list so that it is automatically archived.
  1. If the requirements are brought to the IETF as a preliminary

investigation (see Section 4.2.1) through a formal liaison, the

   rejection MUST be delivered through a formal liaison response.
  1. If a requirements statement I-D has been produced and discussed on

an IETF email list, the response MUST be made as an email response

   and copied to the email list.
  1. If a requirements statement I-D has been produced and brought to

the IETF through a formal liaison, the rejection MUST be delivered

   through a formal liaison response.
  1. If an IETF working group has been involved in the review or

production of any Internet-Drafts for the requirements or for the

   solutions, the working group MUST be notified of the rejection and
   the reasons.
 The responsibility for the generation of the response lies with the
 person, people, or group that instigates the rejection.  This may be
 the IESG, one or more Area Directors, one or more working group
 chairs, or a designated expert [RFC2434].  In the case of the use of
 a liaison relationship, the IETF's liaison manager has responsibility
 for ensuring that the procedures in this document, and particularly
 the rejection procedures, are followed.

5.3. Appeals

 [RFC2026] contains additional information related to procedure
 disagreements and appeals.  The rejection of a requirements statement
 I-D as described in Sections 5.1 and 5.2 may be appealed in the event

Andersson & Farrel Best Current Practice [Page 18] RFC 4929 MPLS and GMPLS Change Process June 2007

 it is disputed and cannot be reversed by direct discussion between
 the parties.  The conflict resolution and appeal mechanism is
 documented in [RFC2026].

6. Abandonment of the Solutions I-D

 Once the solutions work has been started by the PSWG, it may be
 abandoned before completion.  This can happen if the PSWG chairs
 determine that there is no longer working group support for doing the
 work.  This could arise, for example, if no one (including the
 originators of the requirements statement I-D) is willing to
 contribute to the development of a solutions I-D.
 In the event that the solutions work is abandoned by the PSWG, the
 Area Directors responsible for the PSWG MUST be consulted.  The
 originators of the requirements statement I-D MUST be informed that
 the work has been abandoned using a mechanism dependent on how the
 requirements were introduced (as discussed in Section 5.2).
 If the solution is abandoned in this way, work on solutions for the
 requirements MUST NOT be started in another forum.  The status of
 extensions and changes to the (G)MPLS protocols with regard to the
 specific requirements returns to how it was before the process
 started.  Any new examination of the requirements MUST commence at
 the top of the process.

6.1. Appeals

 The abandonment of a solutions I-D may be appealed in the event it is
 disputed and cannot be reversed by direct discussion between the
 parties.  The conflict resolution and appeal mechanism is documented
 in [RFC2026].

7. (G)MPLS Integrity and Ownership

 The (G)MPLS working groups are REQUIRED to protect the architectural
 integrity of the (G)MPLS protocols and MUST NOT extend the GMPLS
 architecture with features that do not have general use beyond the
 specific case.  They also MUST NOT modify the architecture just to
 make some function more efficient at the expense of simplicity or
 generality.
 The architectural implications of additions or changes to the (G)MPLS
 protocols MUST consider interoperability with existing and future
 versions of the protocols.  The effects of adding features that
 overlap, or that deal with a point solution and are not general, are
 much harder to control with rules and risk impacting the protocol as
 a whole.  Therefore, to minimize operational and technical risks to

Andersson & Farrel Best Current Practice [Page 19] RFC 4929 MPLS and GMPLS Change Process June 2007

 the (G)MPLS technology, IETF processes SHALL be followed for any
 requests on extensions to (G)MPLS protocols.  With respect to (G)MPLS
 protocols, the (G)MPLS PSWG is the chartered "owner" of the (G)MPLS
 protocol, as long as the working group exists.  All changes or
 extensions to (G)MPLS MUST first be reviewed by the (G)MPLS PSWG.

8. Security Considerations

 All requirements statement I-Ds MUST give full consideration to the
 security impact of the proposed additional features or functions.
 All solutions I-Ds MUST consider the impact on the security of the
 protocol extensions and to the pre-existing protocol.
 This documents does not itself introduce any security issues for any
 (G)MPLS protocols.
 The IETF process is itself at risk from denial of service attacks.
 This document utilizes the IETF process and adds clarity to that
 process.  It is possible, therefore, that this document might put the
 IETF process at risk.
 Therefore, provided that the number of requirements statement I-Ds is
 not unreasonable, there will be no significant impact on the IETF
 process.  The rate of arrival of requirements statement I-Ds MAY be
 used by the IESG to detect denial of service attacks, and the IESG
 SHOULD act on such an event depending on the source of the
 requirements statement I-D and the perceived relevance of the work.
 The IESG might, for example, discuss the issue with the management of
 external organizations.

9. Acknowledgements

 The input given by Bert Wijnen has been useful and detailed.
 Review feedback and discussions with various members of the ITU-T has
 been helpful in refining the process described in this document.
 Thanks in particular to the members of Question 14 of Study Group 15,
 and to the management of Study Group 15.  Important discussions were
 held with the following participants in the ITU-T: Yoichi Maeda, Greg
 Jones, Stephen Trowbridge, Malcolm Betts, Kam Lam, George Newsome,
 Eve Varma, Lyndon Ong, Stephen Shew, Jonathan Sadler, and Ben Mack-
 Crane.
 Thanks for further review comments to Brian Carpenter, Stewart
 Bryant, Sam Hartman, Mark Townsley, and Dave Ward.  Thanks to Spencer
 Dawkins for the GenArt review.

Andersson & Farrel Best Current Practice [Page 20] RFC 4929 MPLS and GMPLS Change Process June 2007

10. IANA Considerations

 This document makes no specific requests to IANA for action.  The
 procedures described in this document assume that IANA will adhere to
 the allocation policies defined for the (G)MPLS codepoint registries
 and that the IETF will not endorse allocation of codepoints from
 those registries except where work has been carried out in accordance
 with the procedures described in this document.

11. References

11.1. Normative References

 [RFC2026]  Bradner, S., "The Internet Standards Process -- Revision
            3", BCP 9, RFC 2026, October 1996.
 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC2418]  Bradner, S., "IETF Working Group Guidelines and
            Procedures", BCP 25, RFC 2418, September 1998.
 [RFC2434]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
            IANA Considerations Section in RFCs", BCP 26, RFC 2434,
            October 1998.
 [RFC4052]  Daigle, L., Ed., and Internet Architecture Board, "IAB
            Processes for Management of IETF Liaison Relationships",
            BCP 102, RFC 4052, April 2005.
 [RFC4053]  Trowbridge, S., Bradner, S., and F. Baker, "Procedures for
            Handling Liaison Statements to and from the IETF", BCP
            103, RFC 4053, April 2005.
 [RFC4775]  Bradner, S., Carpenter, B., Ed., and T. Narten,
            "Procedures for Protocol Extensions and Variations", BCP
            125, RFC 4775, December 2006.  2006.

11.2. Informative References

 [RFC3356]  Fishman, G. and S. Bradner, "Internet Engineering Task
            Force and International Telecommunication Union -
            Telecommunications Standardization Sector Collaboration
            Guidelines", RFC 3356, August 2002.

Andersson & Farrel Best Current Practice [Page 21] RFC 4929 MPLS and GMPLS Change Process June 2007

Authors' Addresses

 George Swallow
 Cisco Systems
 EMail: swallow@cisco.com
 Deborah Brungard
 AT&T
 EMail: dbrungard@att.com
 Bill Fenner
 AT&T
 EMail: fenner@research.att.com
 Ross Callon
 Juniper Networks
 EMail: rcallon@juniper.net
 Kireeti Kompella
 Juniper Networks
 EMail: Kireeti@juniper.net
 Alex Zinin
 Alcatel
 EMail: zinin@psg.com
 Scott Bradner
 Harvard University
 EMail: sob@harvard.edu

Editors' Addresses

 Loa Andersson
 Acreo AB
 EMail: loa@pi.se
 Adrian Farrel
 Old Dog Consulting
 EMail: adrian@olddog.co.uk

Andersson & Farrel Best Current Practice [Page 22] RFC 4929 MPLS and GMPLS Change Process June 2007

Full Copyright Statement

 Copyright (C) The IETF Trust (2007).
 This document is subject to the rights, licenses and restrictions
 contained in BCP 78, and except as set forth therein, the authors
 retain all their rights.
 This document and the information contained herein are provided on an
 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
 OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Intellectual Property

 The IETF takes no position regarding the validity or scope of any
 Intellectual Property Rights or other rights that might be claimed to
 pertain to the implementation or use of the technology described in
 this document or the extent to which any license under such rights
 might or might not be available; nor does it represent that it has
 made any independent effort to identify any such rights.  Information
 on the procedures with respect to rights in RFC documents can be
 found in BCP 78 and BCP 79.
 Copies of IPR disclosures made to the IETF Secretariat and any
 assurances of licenses to be made available, or the result of an
 attempt made to obtain a general license or permission for the use of
 such proprietary rights by implementers or users of this
 specification can be obtained from the IETF on-line IPR repository at
 http://www.ietf.org/ipr.
 The IETF invites any interested party to bring to its attention any
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 rights that may cover technology that may be required to implement
 this standard.  Please address the information to the IETF at
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Acknowledgement

 Funding for the RFC Editor function is currently provided by the
 Internet Society.

Andersson & Farrel Best Current Practice [Page 23]

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