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BEST CURRENT PRACTICE
Network Working Group                                  L. Andersson, Ed.Request for Comments: 4929                                      Acreo ABBCP: 129                                                  A. Farrel, Ed.Category: Best Current Practice                       Old Dog Consulting                                                               June 2007Change Process for Multiprotocol Label Switching (MPLS) andGeneralized MPLS (GMPLS) Protocols and ProceduresStatus 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 2007Table of Contents1. Introduction ....................................................31.1. Document Source ............................................41.2. Conventions Used in This Document ..........................42. Overview of (G)MPLS within the IETF .............................42.1. IETF Working Groups Developing (G)MPLS Technology ..........52.1.1. Multiprotocol Label Switching Working Group .........52.1.2. Common Control & Measurement Plane Working Group ....52.1.3. MPLS and CCAMP Division of Work .....................62.2. Other (G)MPLS Technology-Related Working Groups ............62.3. Organizations Outside the IETF .............................73. Overview of (G)MPLS Change Process ..............................84. MPLS and GMPLS Change Process ...................................94.1. Flow Diagram ..............................................104.2. Description of Process Stages .............................114.2.1. Preliminary Investigation ..........................124.2.2. Requirements Statement Evaluation ..................134.2.3. Working Group Procedures ...........................144.2.4. 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 ...................................154.2.7. Solutions Work .....................................155. Rejecting the Requirements Statements I-D ......................165.1. Reasons for Rejection .....................................16      5.2. Actions Required When Rejecting Requirements           Statement I-Ds ............................................185.3. Appeals ...................................................186. Abandonment of the Solutions I-D ...............................196.1. Appeals ...................................................197. (G)MPLS Integrity and Ownership ................................198. Security Considerations ........................................209. Acknowledgements ...............................................2010. IANA Considerations ...........................................2111. References ....................................................2111.1. Normative References .....................................2111.2. Informative References ...................................21Andersson & Farrel       Best Current Practice                  [Page 2]

RFC 4929             MPLS and GMPLS Change Process             June 20071.  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 inSection 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 howAndersson & 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 inRFC 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 thatAndersson & 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 20073.  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 inSection 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:   - that the requirements can be satisfied without modifications to the     (G)MPLS protocolsAndersson & Farrel       Best Current Practice                  [Page 8]

RFC 4929             MPLS and GMPLS Change Process             June 2007   - 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   - that the requirements justify a standards-track change to the     (G)MPLS protocols   - 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   - 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 Overview4.2.  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 20074.2.1.  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 inSection 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 theAndersson & 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 20074.2.3.  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:   - 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   - a rejection of the requirements using the response procedure as     described inSection 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 20074.2.6.  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.   - 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.   - 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.   - 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.  InAndersson & 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.   - 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.   - 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.   - 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.     SeeSection 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 otherAndersson & 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 toSection 5.1).   The communication of the rejection depends on the form of the   original submission as follows.   - If the requirements are brought to the IETF as a preliminary     investigation (seeSection 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.   - If the requirements are brought to the IETF as a preliminary     investigation (seeSection 4.2.1) through a formal liaison, the     rejection MUST be delivered through a formal liaison response.   - 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.   - 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.   - 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 Sections5.1 and5.2 may be appealed in the eventAndersson & 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 inSection 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 toAndersson & 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 200710.  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.  References11.1.  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",BCP103,RFC 4053, April 2005.   [RFC4775]  Bradner, S., Carpenter, B., Ed., and T. Narten,              "Procedures for Protocol Extensions and Variations",BCP125,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 2007Authors' 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.eduEditors' Addresses   Loa Andersson   Acreo AB   EMail: loa@pi.se   Adrian Farrel   Old Dog Consulting   EMail: adrian@olddog.co.ukAndersson & Farrel       Best Current Practice                 [Page 22]

RFC 4929             MPLS and GMPLS Change Process             June 2007Full Copyright Statement   Copyright (C) The IETF Trust (2007).   This document is subject to the rights, licenses and restrictions   contained inBCP 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 inBCP 78 andBCP 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 athttp://www.ietf.org/ipr.   The IETF invites any interested party to bring to its attention any   copyrights, patents or patent applications, or other proprietary   rights that may cover technology that may be required to implement   this standard.  Please address the information to the IETF at   ietf-ipr@ietf.org.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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