If this is intended as a BCP on the general concept of code point
reservation, there are a lot of issues -- and existing RFCs -- that need
to be addressed:
RFC2780
RFC3692
RFC4727
RFC5226
RFC6994
Issues include:
reserving values in a numeric range for:
future variants
extensibility of the range
concurrent signals:
as values within the range
as values orthogonal to the range
reserved flags
default when sent
interpretation at receiver
ignore unless signaled elsewhere
require 0
treat 0 as ignore/1 as "upgraded"
There's also the issue of the space of codepoints, i.e., port numbers
are much more limited than service names, even though both are finite.
I think there's danger in assuming that "0" means "unset"; that's not
"Reserved", but really "means that the codepoint is not supported or not
set" and is thus assigned. Zero is often reserved for other reasons.
Reserved codepoints MUST NOT be used and MUST NOT be interpreted.
The semantics of why a codepoint is reserved MUST NOT be indicated;
that's not "Reserved" but "Assigned for future use".
I.e., "Reserved" means only that - with an undefined future use. Every
assignment - including Reserved - MUST have a defined sender and
receiver action:
MUST NOT be set until defined
MUST be silently ignored? or generate error? etc.
I don't think this doc should specify the behavior, but should indicate
that a behavior MUST be specified.
That's the short list off issues off the top of my head. If you're
interested in more feedback or text, contact me off-list.
Joe
On 9/18/2015 7:20 AM, Jeffrey Haas wrote:
After a little discussion and initial review on the wgchairs list, I'd like
to draw the broader IETF community's attention to the draft below. It's my
belief that the practice of reserving bottom and top code points is fairly
common in the IETF (and perhaps it has analogs in other SDOs?). However, I
don't think the practice has been written down anywhere for the benefit of
those who may be new to our organization.
Note that the goal of this document is to discuss specifically certain
reserved values. It does not have the intention of discussing allocation
strategies for various ranges and their types. (See
draft-leiba-cotton-iana-5226bis-11 and RFC 3692 as examples of such
documents.) As such, I don't believe this document should have much a
creeping scope of things to cover.
The goal would be to submit this as a BCP document sometime this year,
potentially as an AD-sponsored draft.
I welcome your comments.
-- Jeff
----- Forwarded message from internet-drafts(_at_)ietf(_dot_)org -----
Date: Fri, 18 Sep 2015 07:09:38 -0700
From: internet-drafts(_at_)ietf(_dot_)org
To: i-d-announce(_at_)ietf(_dot_)org
Subject: I-D Action: draft-haas-code-point-reservation-bcp-02.txt
A New Internet-Draft is available from the on-line Internet-Drafts
directories.
Title : Reservation Strategies for the Zeroth and Last Code
Points in IETF Registries and for Bit Field Registries
Author : Jeffrey Haas
Filename : draft-haas-code-point-reservation-bcp-02.txt
Pages : 5
Date : 2015-09-18
Abstract:
This document describes common code point reservation strategies for
the zeroth and last code points in IANA-managed IETF registries and
for bit-field registries. This document additionally provides the
reasoning to support these strategies and their adoption as Best
Current Practices to be applied to all IETF registries.
The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-haas-code-point-reservation-bcp/
There's also a htmlized version available at:
https://tools.ietf.org/html/draft-haas-code-point-reservation-bcp-02
A diff from the previous version is available at:
https://www.ietf.org/rfcdiff?url2=draft-haas-code-point-reservation-bcp-02
Please note that it may take a couple of minutes from the time of submission
until the htmlized version and diff are available at tools.ietf.org.
Internet-Drafts are also available by anonymous FTP at:
ftp://ftp.ietf.org/internet-drafts/
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