Network Working Group L. Andersson (Editor)
Internet-Draft Acreo AB
Proposed Status: Best Current Practice A. Farrel (Editor)
Old Dog Consulting
November 2006
Change Process for Multiprotocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) Protocols and Procedures
draft-andersson-rtg-gmpls-change-07
Status of this Memo
By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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Internet-Drafts are draft documents valid for a maximum of six months
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material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt.
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Abstract
The issues surrounding the extensibility of IETF protocols have been
widely debated. These issues include when it is reasonable to
extend IETF protocols with little or no review, and when extensions
or variations need to be reviewed by the larger IETF community.
Experience with IETF protocols has shown that extensibility of
protocols without early IETF review can cause problems.
The Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS)
suites of protocols have become popular for a number of applications
and deployment scenarios. One result of this popularity is a large
number of suggestions for modifications and extensions.
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This document defines a flexible and responsive process for the IETF
to handle suggestions for extensions to the MPLS and GMPLS protocols,
and clarifies the IETF's responsibility to supervise the growth and
evolution of MPLS and GMPLS protocols.
The process describes how individual draft submissions, working
group drafts, and inputs from external standards bodies influence the
development of the MPLS and GMPLS standards. When possible, existing
liaison relationships are used.
Table of Contents
1. Introduction ................................................... 3
1.1 Document Source ............................................... 4
1.2 Conventions Used in this Document ............................. 4
2. Applicability of the (G)MPLS Change Process .................... 4
2.1 IETF Working Groups Developing (G)MPLS Technology ............. 4
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 Working Groups ...................... 6
2.3 Organizations Outside the IETF ............................... 7
2.4 Terminology .................................................. 7
3. Summary of Procedures .......................................... 9
4. MPLS and GMPLS Change Process ................................ 10
4.1 Flow Diagram ................................................ 11
4.2 Description of Process Stages ............................... 12
4.2.1 Preliminary Investigation .................................. 12
4.2.2 Requirements Statement Evaluation .......................... 13
4.2.3 Chartering or Rechartering the REWG ........................ 14
4.2.4 REWG Evaluation of the Requirements Statement I-D .......... 14
4.2.5 AD Evaluation of Completed Requirements Statement I-D ...... 15
4.2.6 IESG and IAB review of Requirements Statement I-D and PSWG
Charter .................................................... 15
4.2.7 Solutions Work ............................................. 15
5. Rejecting 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 ...................................................... 19
6. Abandonment of the Solutions I-D .............................. 19
6.1 Appeals ...................................................... 19
7. (G)MPLS Integrity ............................................. 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
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1. Introduction
[PROT-EXT] discusses procedural issues related to the extensibility
of IETF protocols, including when it is reasonable to extend IETF
protocols with little or no review, and when extensions or variations
need to be reviewed by the larger IETF community. Experience with
IETF protocols has shown that extensibility of protocols without
early IETF review can cause problems. [PROT-EXT] also recommends that
major extensions to, or variations of, IETF protocols only take place
through normal IETF processes or in coordination with the IETF.
This document recognizes that the Multiprotocol Label Switching
(MPLS) and Generalized MPLS (GMPLS) protocol families were created
within the IETF and constitute significant protocol suites that are
strategic to the development of the Internet. These protocols should
not be extended or varied without IETF review, and they should
only be extended within the IETF process.
The process described in this document allows individuals, IETF
working groups, and external standards bodies to influence the
development of MPLS and GMPLS protocols and related standards. The
process means that MPLS and GMPLS extensions and changes can only be
done through or in coordination with the IETF. In particular, the
MPLS and/or CCAMP working groups or their successors need to be
involved in the process. When possible, existing liaison
relationships ([RFC4052], [RFC4053]) are leveraged. The IETF's formal
standards process is defined in [RFC2026] and [RFC2418], and is not
changed by this document.
The IETF will not endorse the publication of any MPLS or GMPLS
protocol or technology extensions in RFCs or other documents where
the process described here has not been followed. If publication of
individual Internet-Drafts describing extensions or changes to the
MPLS or GMPLS protocols is requested of the RFC Editor the documents
will be returned to the process described in this document using the
mechanism described in [RFC3932].
IANA is responsible for managing many codepoints registries including
those for MPLS and GMPLS protocols. These registries have specific
allocation policies that IANA uses in order to determine whether
codepoints can be allocated and which codepoints to allocate. In many
cases, the rules require IANA to refer back to the IETF when asked to
make an allocation. In the case of changes or extensions to the MPLS
or GMPLS protocols, IANA will use its normal documented procedures to
judge whether or not a code point allocation should be made.
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.
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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.
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 liaison
to the ITU-T. It has 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 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. Applicability of the (G)MPLS Change Process
This section outlines the applicability of the (G)MPLS change process
specified in this document. It lists the key IETF working groups
developing the (G)MPLS technology, examples of IETF working groups
using the (G)MPLS technology, and possible parties interested in
using, extending, or changing the (G)MPLS technology.
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.
A section listing terminology local to this document that will be
used in specifying the change process is also included.
2.1 IETF Working Groups Developing (G)MPLS Technology
Two working groups in the IETF's Routing Area have been responsible
for work to develop the (G)MPLS technology. The Multiprotocol Label
Switching (MPLS) working group and the Common Control and Measurement
Plane (CCAMP) working group.
The sections below give brief overviews of the work these two IETF
working groups were chartered to do.
The IETF may, in the future, define additional working groups to work
on specific chartered issues related to (G)MPLS. Further, specific
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existing working groups such as those listed in section 2.2 may be
rechartered by the IESG to work on particular aspects of the (G)MPLS
protocols. The procedure for chartering new or existing working
groups to undertake (G)MPLS work is covered in section 4.2.3.
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.
The procedures in this document assume that the MPLS working group
remains the authority on MPLS technologies, but acknowledges that
the IETF may appoint another working group (using the procedures in
this document) 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 may appoint a Designated
Expert (sometimes known as a Caretaker) 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
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 (using the procedures in
this document) to handle specific extensions or changes to the
protocols. Further, in the event that the CCAMP working group
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completes its work and is closed, the IETF may appoint a Designated
Expert (sometimes known as a Caretaker) 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 technology.
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 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; for example, the IP over Optical (IPO) working group
and the Internet Traffic Engineering working group (TEWG). These
working groups have not specified any protocols, but have been a
source of problem statements and requirements to be considered by the
(G)MPLS working groups.
Other working groups, e.g., the Bidirectional Forwarding Detection
(BFD) working group, also use the (G)MPLS protocols and mechanisms.
When any of these working groups needs to extend or change the
(G)MPLS protocols the procedures specified in this document are
applicable. Some of those working groups (again, for example, the
BFD working group) are already chartered for requirements evaluation
and protocol specification, and can fit into the procedures in those
roles.
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. The
work of the L2VPN and L3VPN working groups does not include
specifying new protocols, however, protocol changes and extensions
to the (G)MPLS protocols may be needed. If so, the procedures
specified in this document 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,
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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 another
working group in the Internet Area that also uses the (G)MPLS
protocols in its specifications. Should the PWE3 specifications
require extension or changes to the (G)MPLS protocols the procedures
specified in this document are applicable.
It is assumed that the change process for the MPLS and CCAMP working
groups, specified in this document, will be applicable or at least
adaptable to other (G)MPLS technology working groups if such a need
should arise.
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.
It should be noted that the first stage in the change process is an
optional Preliminary Investigation (see Section 4.2.1). This stage is
explicitly included to allow external organizations to discuss
requirements and proposed uses of the (G)MPLS technologies without
the need to first develop Internet-Drafts, and builds on existing
liaison processes where they exist. It is recognized that it is in
the interests of all concerned to begin discussions as early as
possible.
2.4 Terminology
This section defines terms for use in the context of this document.
o (G)MPLS protocols
The (G)MPLS protocols are the protocols and protocol variants
developed by the IETF to control, manage, or measure MPLS or GMPLS
networks and their component devices.
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The set of RFCs that constitutes the (G)MPLS protocols are the
standards track RFCs from the (G)MPLS working groups (see below).
A list of these RFCs is not supplied here since new RFCs are
produced from time to time.
For the purpose of extending and changing any protocols specified
in any specification developed by the (G)MPLS working groups,
those protocols are considered to be part of the (G)MPLS
protocols.
o (G)MPLS working groups
The (G)MPLS working groups are the MPLS and the CCAMP working
groups, and any future working group specifically chartered by the
IESG to work on the development or extension of the (G)MPLS
protocols.
o (G)MPLS technology working group
Any working group chartered by the IESG to specify requirements
for the (G)MPLS protocols, and any working group that specifies a
use for the (G)MPLS protocols. This also includes the (G)MPLS
working groups.
o Requirement evaluating working group (REWG)
The REWG is the IETF working group charged with the task of
evaluating a specific set of requirements and the associated
problem statement.
o Preliminary Investigation
An optional preliminary phase that may be used to exchange views
on a proposed requirement and usage of the (G)MPLS technologies
without going to the effort of writing an Internet-Draft. This
phase may be particularly useful to SDOs that have already
invested heavily in documenting a problem statement, or may be
used by anyone who wishes to hold discussions on the use of
(G)MPLS.
o Protocol specifying working group (PSWG)
The PSWG is the working group chartered by the IESG to specify
changes or extensions to the (G)MPLS protocols either as part of
the normal IETF process or in response to a requirements draft.
o Problem statement Internet-Draft
The Internet-Draft that initiates the discussion on changing or
extending the (G)MPLS protocols. This draft includes a detailed
problem description that (G)MPLS is called on to solve. The
problem statement draft may also include the requirements (see
requirements statement Internet-Draft, below).
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o Requirements statement Internet-Draft
This Internet-Draft provides a detailed list of the abstract
functional requirements that the (G)MPLS extensions or changes
need to fulfill. These requirements should not constrain the
solution, but should provide all of the information necessary to
develop a satisfactory solution. This draft may be merged with the
problem statement draft (see above).
o Solutions Internet-Draft
A specification of extensions or changes to the (G)MPLS protocols
to meet the requirements in the requirement statement
Internet-Draft.
3. Summary of Procedures
This non-normative section is intended to provide a high-level view
of the procedures in this document to illustrate how they work and to
introduce the mechanisms that 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
preliminary investigation phase may be used to discuss the
requirements with the IETF. This may lead to an understanding that
the problem is already solved, is outside the scope of the IETF, or
requires more investigation possibly leading to changes to the
(G)MPLS protocols.
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. As described in
[RFC4052], when the requirements come from an external organization
informal communications such as e-mail to working group mailing lists
often facilitates cooperative work. However, if desired, the
Internet-Draft containing the requirement may be submitted to the
working group using a liaison statement. That way, the IETF's
response to the request will be given as the reply to the liaison,
with no risk of confusing an individual participant's opinion for
that of the group as can happen on mailing lists.
The IETF, through the Routing Area Directors and the chairs of the
MPLS and CCAMP working groups, 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
- that the requirements are not sufficiently general to warrant a
change to the (G)MPLS protocols
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- that the requirements justify a change to the (G)MPLS protocols
that will be created by the IETF or within another organization
- 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 compete through the normal
IETF process with other proposed solutions, and none will be adopted
as an IETF working group draft until the requirements are agreed by
the REWG chairs to be stable and, in any case, not before the PSWG
has a charter item to cover the solutions work.
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 precise required behavior.
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. 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 extended 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.
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4.1 Flow Diagram
Figure 1 is presented to give a visual overview of the process. It
does not contain all of the possible interactions of procedures, and
the text in the subsequent sections should be used for a definitive
description of the process.
Start +-------------+
| |optional |
+--<--------------------|preliminary |<-------Start
| |investigation|
V +-------------+
+------------+ +---------+ +---------+
|requirements| discussion |review by| YES | IESG/ | YES
|statement |----------->|WG chairs|------------->| IAB |------+
|I-D | on mailing |and ADs | request to |decision | |
+------------+ list +---------+ IESG/IAB 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 |
+-----------| IAB |<---------------|review |<------------| eval |
|WG |decision| request to | | YES | |
|chartered +--------+ IESG/IAB to +-------+ +------+
|to work approve I-D
| and charter
|
| +---------+
| | IETF | +-----+
+--------->| WG |-----/ /---->| RFC |
+---->| process | +-----+
| +---------+
solutions
I-D
Figure 1: Change Process Overview
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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 (G)MPLS
working groups, the Routing Area and the IETF in general.
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 REWG or to the Routing Area, and the initiators of the
liaison SHOULD make themselves available for discussion on the
selected mailing list. If a formal liaison is used, the IETF MUST
respond to pursue the discussion.
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 identical to those for the
requirements statement evaluation phase described in section 4.2.2,
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but the requirements statement evaluation phase MUST form part of the
process if the requirements are understood and the IETF would like to
develop protocol solutions - the process cannot move direct from the
preliminary investigation phase to the development of solutions.
4.2.2 Requirements Statement Evaluation
Before the IETF can formally pronounce on requirements to change or
extend the (G)MPLS protocols, a requirements statement I-D MUST be
written and submitted to the IETF for publication.
The requirements statement I-D MUST be introduced to the IETF through
an email to the REWG mailing list or 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 appropriate
mailing lists.
After discussion on the IETF mailing lists, the appropriate IETF
working group chairs and the Routing Area Directors MUST decide
whether the requirements will be formally evaluated by the IETF, and
MUST deliver a response to the requirements statement I-D.
If the requirements statement I-D is brought to the IETF through a
formal liaison, the working group chairs, ADs or their delegates MUST
respond using one of the following answers in a formal liaison reply.
If a formal liaison was not used the response SHOULD be delivered
using one of the following answers in an email copied to the
appropriate mailing lists.
a. Requirements not understood. Further discussion 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
appropriate 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.
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4.2.3 Chartering or Rechartering the REWG
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 Routing Area Directors SHOULD designate the
working group as the REWG and pass the requirements statement I-D to
the working group for evaluation.
If a new charter item is required for an existing working group, the
Routing Area Directors with assistance from working group chairs MUST
apply to the IESG and IAB for a modification of an existing working
group's charter or for the creation of a new working group. If the
IESG approves the charter, the requirements statement I-D is passed
to the REWG for evaluation. If the charter change is not approved,
the IESG MUST respond to the requirements statement I-D and, if the
requirements were introduced through a formal liaison from another
SDO, the IESG MUST send a liaison response using the options
described in Section 5, although the IESG MAY delegate such
responses.
Under unusual circumstances the Routing Area Directors MAY decide to
charter a new working group to act as the REWG. In this case, the ADs
are responsible for drafting the charter of the new working group and
MUST follow the procedures set out in the previous paragraph.
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 MUST 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 following exactly the same format
and procedure as described in Section 5.
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4.2.5 AD Evaluation of Completed Requirements Statement I-D
As with all Internet-Drafts produced by a working group, the ADs MUST
review the completed requirements statement I-D produced by the REWG
to determine its fitness for publication. At their discretion, the
ADs MAY use an Area Directorate and/or other subject matter experts
to assist them in this review.
The result of the AD review MAY request the REWG to do further work
on the I-D in which case the previous step and this one will be
repeated.
The ADs SHOULD NOT reject the requirements statement I-D outright at
this stage since the requirements have already been accepted by the
ADs at an earlier stage. However, in some situations (such as a
significant change in related circumstances) the ADs MAY reject the
requirements statement I-D using the format and procedure described
in Section 5.
When the ADs accept the requirements statement I-D they MUST pass it
to the IESG for review, and propose any charter changes necessary to
select a PSWG.
4.2.6 IESG review of Requirements Statement I-D and PSWG Charter
As with all Internet-Drafts, the IESG MUST take a ballot on the
progression of the requirements statement I-D.
If the IESG rejects the requirements statement I-D, it MUST generate
a response to the requirements as described in Section 5.
The IESG MUST take a ballot on any proposed charter changes for the
PSWG. This MAY include the formation of a new working group
specifically to work on the solutions, although it is also possible
that the solutions work is covered by an existing working group
charter without any changes.
If the IESG rejects working group charter changes such that it is not
possible for the IETF to work on solutions for the requirements in
the requirements statement I-D, this MUST be treated as a rejection
of the requirements statement I-D, and the requirements statement I-D
MUST NOT be published as an RFC. In this case the IESG MUST reject
the requirements statement I-D using the format and procedure
described in Section 5.
4.2.7 Solutions Work
Once the requirements statement I-D has been approved by the IESG it
will enter the RFC Editor's queue and be handled according to normal
IETF process.
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Once the PSWG has been identified and (re-)chartered as necessary and
the requirements statement I-D has been approved by the IESG, the
PSWG can 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
publication, 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-Ds until the PSWG has a
charter item that covers the work and the REWG chairs are confident
that the requirements are stable. Even at this stage in the process,
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.
The final development of the solutions I-D is subject to the normal
working group review, consensus, and last call within the PSWG.
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 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.
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 process described in this section.
5.1 Reasons for Rejection
The requirements statement I-D can only be rejected using one of the
following reasons. Each reason MUST be stated with the acceptable
next steps as described here.
- Requirements not understood. Either during preliminary
investigation or during evaluation of the requirements statement
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I-D, it wasn't 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.
- 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 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. In this case, the IETF MUST
NOT restrict the authors of the requirements statement I-D from
working on a solution. The solution SHALL be presented to the IETF
for review and possible publication as an Informational or
Experimental RFC, and the IETF SHALL NOT block applications to IANA
for codepoints.
- 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 re-introduced
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
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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.
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. The reasons MUST be based on the list in
Section 5.1.
The form 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 protocol caretaker. 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.
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5.3 Appeals
The rejection of a requirements statement I-D as described in
Sections 5.1 and 5.2 may be appealed in the event it is considered to
be deeply incorrect 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
considered to be deeply incorrect and cannot be reversed by direct
discussion between the parties. The conflict resolution and appeal
mechanism is documented in [RFC2026].
7. (G)MPLS Integrity
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 be 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
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much harder to control with rules. Therefore the (G)MPLS technology
calls for this architectural guardianship by its working groups.
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 details to that
process. It is possible, therefore, that this document might put the
IETF process at risk. Although this document places additional
requirements on key individuals within the IETF, those requirements
are not substantial for any individual requirements statement I-D
since the responsibility for the majority of the work lies with the
REWG and PSWG with an underlying assumption that the authors of the
requirements statement I-D will participate in the working group
process.
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
and Dave Ward. Thanks to Spencer Dawkins for the GenArt review.
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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.
[RFC4052] Daigle, L., "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, RFC4053, April 2005.
[PROT-EXT] Bradner, S., and Carpenter, B., "Procedures for protocol
extensions and variations", draft-carpenter-protocol-
extensions, work in progress.
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.
[RFC3932] Alvestrand, H., "The IESG and RFC Editor Documents:
Procedures", BCP 92, RFC 3932, October 2004.
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Editor' Addresses
Loa Andersson
Acreo AB
Email: loa@pi.se
Adrian Farrel
Old Dog Consulting
Email: adrian@olddog.co.uk
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
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Andersson and Farrel [Page 22]
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