RFC5131

From RFC-Wiki

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.

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.

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.

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.

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: [email protected]
              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
        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

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.

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.

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.

References

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.

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.

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: [email protected]

Full Copyright Statement

Copyright (C) The IETF Trust (2007).

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