Network Working Group D. McWalter, Ed.
Request for Comments: 5131 Data Connection Ltd
Category: Standards Track December 2007
A MIB Textual Convention for Language Tags
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Abstract
This MIB module defines a textual convention to represent BCP 47
language tags. The intent is that this textual convention will be
imported and used in MIB modules that would otherwise define their
own representation.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. The Internet-Standard Management Framework . . . . . . . . . . 2
4. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 4
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 4
8.1. Normative References . . . . . . . . . . . . . . . . . . . 4
8.2. Informative References . . . . . . . . . . . . . . . . . . 5
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RFC 5131 LANGTAG TC MIB December 2007
1. Introduction
This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols in the Internet community.
It defines a textual convention to represent BCP 47 [RFC4646]
language tags.
The LangTag TEXTUAL-CONVENTION defined by this RFC replaces the
similar LanguageTag TEXTUAL-CONVENTION defined by RFC 2932 [RFC2932].
The old LanguageTag TEXTUAL-CONVENTION is used by some existing MIB
modules. New MIB modules should use the LangTag TEXTUAL-CONVENTION,
which has been created (and is to be preferred) for the following
reasons:
o Its syntax description is current, and is more comprehensive.
o It is short enough to use as an index object without subtyping,
yet is of adequate length to represent any language tag in
practice.
o It is provided in a dedicated MIB module to simplify module
dependencies.
It is not possible to apply changes in syntax and length to an
existing textual convention. This is why the creation of a new
textual convention with a new name was necessary.
2. Terminology
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].
3. The Internet-Standard Management Framework
For a detailed overview of the documents that describe the current
Internet-Standard Management Framework, please refer to section 7 of
RFC 3410 [RFC3410].
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. MIB objects are generally
accessed through the Simple Network Management Protocol (SNMP).
Objects in the MIB are defined using the mechanisms defined in the
Structure of Management Information (SMI). This memo specifies a MIB
module that is compliant to the SMIv2, which is described in STD 58,
RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
[RFC2580].
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RFC 5131 LANGTAG TC MIB December 2007
4. Definitions
LANGTAG-TC-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, mib-2 FROM SNMPv2-SMI -- [RFC2578]
TEXTUAL-CONVENTION FROM SNMPv2-TC; -- [RFC2579]
langTagTcMIB MODULE-IDENTITY
LAST-UPDATED "200711090000Z" -- 9 November 2007
ORGANIZATION "IETF Operations and Management (OPS) Area"
CONTACT-INFO "EMail: ops-area@ietf.org
Home page: http://www.ops.ietf.org/"
DESCRIPTION
"This MIB module defines a textual convention for
representing BCP 47 language tags."
REVISION "200711090000Z" -- 9 November 2007
DESCRIPTION
"Initial revision, published as RFC 5131.
Copyright (C) The IETF Trust (2007). This version of this
MIB module is part of RFC 5131; see the RFC itself for full
legal notices."
::= { mib-2 165 }
LangTag ::= TEXTUAL-CONVENTION
DISPLAY-HINT "1a"
STATUS current
DESCRIPTION
"A language tag, constructed in accordance with BCP 47.
Only lowercase characters are allowed. The purpose of this
restriction is to provide unique language tags for use as
indexes. BCP 47 recommends case conventions for user
interfaces, but objects using this TEXTUAL-CONVENTION MUST
use only lowercase.
Values MUST be well-formed language tags, in conformance
with the definition of well-formed tags in BCP 47. An
implementation MAY further limit the values it accepts to
those permitted by a 'validating' processor, as defined in
BCP 47.
In theory, BCP 47 language tags are of unlimited length.
The language tag described in this TEXTUAL-CONVENTION is of
limited length. The analysis of language tag lengths in BCP
47 confirms that this limit will not pose a problem in
practice. In particular, this length is greater than the
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RFC 5131 LANGTAG TC MIB December 2007
minimum requirements set out in Section 4.3.1.
A zero-length language tag is not a valid language tag.
This can be used to express 'language tag absent' where
required, for example, when used as an index field."
REFERENCE "RFC 4646 BCP 47"
SYNTAX OCTET STRING (SIZE (0 | 2..63))
END
5. Security Considerations
This MIB module does not define any management objects. Instead, it
defines a textual convention that may be imported by other MIB
modules and used for object definitions.
Meaningful security considerations can only be written in the MIB
modules that define management objects. This document therefore has
no impact on the security of the Internet.
6. IANA Considerations
LANGTAG-TC-MIB is rooted under the mib-2 subtree. IANA has assigned
{ mib-2 165 } to the LANGTAG-TC-MIB module specified in this
document.
7. Acknowledgements
This MIB module is a reworking of existing material from RFC 2932.
This module was generated by editing together contributions from
Randy Presuhn, Dan Romascanu, Bill Fenner, Juergen Schoenwaelder,
Bert Wijnen, Doug Ewell, and Ira McDonald.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2578] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Structure of Management Information
Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
[RFC2579] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Textual Conventions for SMIv2",
STD 58, RFC 2579, April 1999.
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RFC 5131 LANGTAG TC MIB December 2007
[RFC2580] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Conformance Statements for SMIv2", STD 58, RFC 2580,
April 1999.
[RFC4646] Phillips, A. and M. Davis, "Tags for Identifying
Languages", BCP 47, RFC 4646, September 2006.
8.2. Informative References
[RFC2932] McCloghrie, K., Farinacci, D., and D. Thaler, "IPv4
Multicast Routing MIB", RFC 2932, October 2000.
[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction and Applicability Statements for Internet-
Standard Management Framework", RFC 3410, December 2002.
Author's Address
David McWalter (editor)
Data Connection Ltd
100 Church Street
Enfield EN2 6BQ
United Kingdom
EMail: dmcw@dataconnection.com
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RFC 5131 LANGTAG TC MIB December 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
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RFC, FYI, BCP