RFC4020-Early IANA Allocation of Standards Track Code Points

Network Working Group K. Kompella

Request for Comments: 4020 Juniper Networks

BCP: 100 A. Zinin

Category: Best Current Practice Alcatel

February 2005

Early IANA Allocation of Standards Track Code Points

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.

Abstract

This memo discusses earlier allocation of code points by IANA as a

remedy to the problem created by the "Standards Action" IANA policy

for protocols for which, by the IETF process, implementation and

deployment eXPerience is desired or required prior to publication.

1. IntrodUCtion

In Standards Track RFCs, there is often a need to allocate code

points for various objects, messages, or other protocol entities so

that implementations can interoperate. Many of these code point

spaces have registries handled by the Internet Assigned Number

Authority (IANA). Several IANA allocation policies are described in

RFC 2434 [2434]. Some of them, such as First Come First Served or

Expert Review, do not require a formal IETF action before the IANA

performs allocation. However, in situations where code points are a

scarce resource and/or the IETF community is willing to retain tight

control of the protocol, policies such as IESG Approval, IETF

Consensus, or Standards Action have been used. The Standards Action

policy represents a problem in situations where implementation and/or

deployment experience are desired or required for the Standards

Action.

To break the deadlock, "pre-RFC" implementations have sometimes

simply chosen some "seemingly unused" code points; these may turn out

to be different from those later assigned by IANA. To make matters

worse, these "pre-RFC" implementations are often deployed. This

creates several potential interoperability problems between early

implementations and implementations of the final standard, as

described below:

1. IANA allocates code points different from those that early

implementations assumed would be allocated. Early implementations

won't interoperate with standard ones.

2. IANA allocates code points used silently for other extensions.

Different extensions will collide.

This gets in the way of the main purpose of standards; namely, to

facilitate interoperable implementations.

It is easy to say that pre-RFC implementations should be kept private

and should not be deployed; however, both the length of the standards

process and the immense value of early implementations and early

deployments suggest finding a better solution. As an example, in the

case of documents produced by Working Groups in the Routing Area, a

pre-RFC implementation is highly desirable and sometimes even

required, and early deployments provide useful feedback on the

technical and operational quality of the specification.

This memo proposes that, under strictly controlled circumstances,

IANA make an early allocation of code points. The memo lays out the

conditions for early allocation, as well as the process to be

followed; it also says how these allocations are dealt with in the

event of a failure in the process (such as the RFC not being

published).

This memo only addresses the early allocation of code points from

spaces whose allocation policy is "Standards Action" [2434] AND that

have been amended to permit early allocation. This permission must

be granted by the IESG, and code spaces with permission for early

allocation must be marked as such in the IANA registry.

2. Conditions for Early Allocation

The following conditions must hold before a request may be made for

early allocation of code points:

a) The code points must be from a space designated as "Standards

Action", amended by IESG approval to permit Early Allocation.

b) The format, semantics, processing, and other rules related to

handling the protocol entities defined by the code points

(henceforth called "specifications") must be adequately described

in an Internet draft that is proposed as Standards Track.

c) The specifications of these code points must be stable; i.e., if

there is a change, implementations based on the earlier and later

specifications must be seamlessly interoperable.

d) There is sufficient interest in early (pre-RFC) implementation and

deployment in the community.

If conditions (a) or (b) are not met, then the processes in this memo

do not apply.

3. Process for Early Allocation

There are three processes associated with early allocation: making

the request for code points; following up on the request; and

revoking an early allocation. It cannot be emphasized enough that

these processes must have a minimal impact on IANA itself, or they

will not be feasible.

The processes described below assume that the document in question is

the product of an IETF Working Group. If this is not the case,

replace "WG chairs" below with "shepherding Area Director".

3.1. Request

The process for requesting and oBTaining early allocation of code

points is as follows:

1) The authors (editors) of the document submit a request for early

allocation to the Working Group chairs, specifying which code

points require early allocation and which document they should be

assigned to.

2) The WG chairs determine whether the conditions for early

allocations described in section 2 are met; particularly,

conditions (c) and (d).

3) The WG chairs gauge whether there is consensus within the WG that

early allocation is appropriate in the case of the given document.

4) If it is, with the approval of the Area Director(s), the WG chairs

request IANA to make an early allocation.

5) IANA makes an allocation from the appropriate registry, marking it

as "temporary", valid for a period of one year from the date of

allocation. The date of allocation should also be recorded in the

registry and made visible to the public.

Note that Internet Drafts should not include a specific value of a

code point until this value has been formally allocated by IANA.

3.2. Follow-Up

It is the responsibility of the document authors and the Working

Group chairs to review changes in the document, and especially in the

specifications of the code points for which early allocation was

requested, to ensure that the changes are backward compatible.

If at some point changes that are not backward compatible are

nonetheless required, a decision needs to be made as to whether

previously allocated code points must be deprecated (see section 3.3

for more information on code point deprecation). The considerations

include ASPects such as the possibility of existing deployments of

the older implementations and, hence, the possibility for a collision

between older and newer implementations in the field.

If the document progresses to the point at which IANA normally makes

code point allocations, it is the responsibility of the authors and

the WG chairs to remind IANA that there were early allocations, and

of the code point values so allocated, in the IANA Considerations

section of the RFC-to-be. Allocation is then just a matter of

removing the "temporary" tag from the allocation description.

3.3. Expiry

If early allocations expire before the document progresses to the

point where IANA normally makes allocations, the authors and WG

chairs may follow an abbreviated version of the process in section

3.1 to request renewal of the code points. At most, one renewal

request may be made; thus, authors should choose carefully when the

original request is to be made.

As an exception to the above rule, under rare circumstances, more

than one allocation renewal may be justified. All such renewal

requests must be reviewed by the IESG. The renewal request to the

IESG must include the reasons why such renewal is necessary, and the

WG's plans regarding the specification.

If a follow-up request is not made, or the document fails to progress

to a Standards Track RFC, the WG chairs are responsible for informing

IANA that the code points are to be marked "deprecated" (and are not

to be allocated). The WG chairs are further responsible for

informing IANA when the deprecated code points can be completely de-

allocated (i.e., made available for new allocations).

In particular, it is not IANA's responsibility to track the status of

allocations, their expiration, or when they may be re-allocated.

Note that if a document is submitted for review to the IESG and at

the time of submission some early allocations are valid (not

expired), these allocations should not be expired while the document

is under IESG consideration or waiting in the RFC Editor's queue

after approval by the IESG.

4. IANA Considerations

This document defines procedures for early allocation of code points

in the registries with the Standards Action policy and as such

directly affects IANA functions.

5. Normative References

[2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA

Considerations Section in RFCs", BCP 26, RFC 2434, October

1998.

6. Security Considerations

It is important to keep in mind 'denial of service' attacks on IANA

as a result of the processes in this memo. There are two that are

immediately obvious: depletion of code space by early allocations and

process overloading of IANA itself. The processes described here

attempt to alleviate both of these, but they should be subject to

scrutiny to ensure this.

7. Acknowledgements

Many thanks to Bert Wijnen, Adrian Farrel, and Bill Fenner for their

input.

Authors' Addresses

Kireeti Kompella

Juniper Networks

1194 N. Mathilda Ave

Sunnyvale, CA 94089 USA

EMail: kireeti@juniper.net

Alex Zinin

Alcatel

701 E Middlefield Rd

Mountain View, CA 94043

EMail: zinin@psg.com

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