rfc4929
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:
- 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
- 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 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:
- 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 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.
- 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. 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.
- 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.
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.
- 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.
- 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.
- 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 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
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]
ERRATA
