RFC5017: MIB Textual Conventions for Uniform Resource Identifiers (URIs)
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Related keywords:
(management information base)
(URI-TC-MIB)
Network Working Group D. McWalter, Ed.
Request for Comments: 5017 Data Connection Ltd
Category: Standards Track September 2007
MIB Textual Conventions for Uniform Resource Identifiers (URIs)
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 textual conventions to represent STD 66
Uniform Resource Identifiers (URIs). The intent is that these
textual conventions will be imported and used in MIB modules that
would otherwise define their own representation(s).
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 1
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. The Internet-Standard Management Framework . . . . . . . . . . 2
4. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 2
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . . 6
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 textual conventions to represent STD 66 [RFC3986] URIs,
which are further described by [RFC3305].
Three textual conventions are defined: one of unrestricted length,
and two of different restricted lengths. Which length is appropriate
will depend on tradeoffs made in particular MIB modules. The purpose
of providing standard restricted-length textual conventions is to
improve compatibility between MIB modules that require restricted-
length URIs.
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If a URI needs to be used as an index object, then the 'Uri' TEXTUAL-
CONVENTION SHOULD be subtyped to a length appropriate for the Object
Identifier (OID) of which it is part. The description of the 'Uri'
TEXTUAL-CONVENTION discusses this case.
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].
4. Definitions
URI-TC-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, mib-2 FROM SNMPv2-SMI -- [RFC2578]
TEXTUAL-CONVENTION FROM SNMPv2-TC; -- [RFC2579]
uriTcMIB MODULE-IDENTITY
LAST-UPDATED "200709100000Z" -- 10 September 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 textual conventions for
representing URIs, as defined by RFC 3986 STD 66."
REVISION "200709100000Z" -- 10 September 2007
DESCRIPTION
"Initial revision, published as RFC 5017.
Copyright (C) The IETF Trust (2007). This version of this
MIB module is part of RFC 5017; see the RFC itself for full
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RFC 5017 URI TC MIB September 2007
legal notices."
::= { mib-2 164 }
Uri ::= TEXTUAL-CONVENTION
DISPLAY-HINT "1a"
STATUS current
DESCRIPTION
"A Uniform Resource Identifier (URI) as defined by STD 66.
Objects using this TEXTUAL-CONVENTION MUST be in US-ASCII
encoding, and MUST be normalized as described by RFC 3986
Sections 6.2.1, 6.2.2.1, and 6.2.2.2. All unnecessary
percent-encoding is removed, and all case-insensitive
characters are set to lowercase except for hexadecimal
digits, which are normalized to uppercase as described in
Section 6.2.2.1.
The purpose of this normalization is to help provide unique
URIs. Note that this normalization is not sufficient to
provide uniqueness. Two URIs that are textually distinct
after this normalization may still be equivalent.
Objects using this TEXTUAL-CONVENTION MAY restrict the
schemes that they permit. For example, 'data:' and 'urn:'
schemes might not be appropriate.
A zero-length URI is not a valid URI. This can be used to
express 'URI absent' where required, for example when used
as an index field.
Where this TEXTUAL-CONVENTION is used for an index field,
it MUST be subtyped to restrict its length. There is an
absolute limit of 128 subids for an OID, and it is not
efficient to have OIDs whose length approaches this
limit."
REFERENCE "RFC 3986 STD 66 and RFC 3305"
SYNTAX OCTET STRING
Uri255 ::= TEXTUAL-CONVENTION
DISPLAY-HINT "255a"
STATUS current
DESCRIPTION
"A Uniform Resource Identifier (URI) as defined by STD 66.
Objects using this TEXTUAL-CONVENTION MUST be in US-ASCII
encoding, and MUST be normalized as described by RFC 3986
Sections 6.2.1, 6.2.2.1, and 6.2.2.2. All unnecessary
percent-encoding is removed, and all case-insensitive
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RFC 5017 URI TC MIB September 2007
characters are set to lowercase except for hexadecimal
digits, which are normalized to uppercase as described in
Section 6.2.2.1.
The purpose of this normalization is to help provide unique
URIs. Note that this normalization is not sufficient to
provide uniqueness. Two URIs that are textually distinct
after this normalization may still be equivalent.
Objects using this TEXTUAL-CONVENTION MAY restrict the
schemes that they permit. For example, 'data:' and 'urn:'
schemes might not be appropriate.
A zero-length URI is not a valid URI. This can be used to
express 'URI absent' where required, for example when used
as an index field.
STD 66 URIs are of unlimited length. Objects using this
TEXTUAL-CONVENTION impose a length limit on the URIs that
they can represent. Where no length restriction is
required, objects SHOULD use the 'Uri' TEXTUAL-CONVENTION
instead. Objects used as indices SHOULD subtype the 'Uri'
TEXTUAL-CONVENTION."
REFERENCE "RFC 3986 STD 66 and RFC 3305"
SYNTAX OCTET STRING (SIZE (0..255))
Uri1024 ::= TEXTUAL-CONVENTION
DISPLAY-HINT "1024a"
STATUS current
DESCRIPTION
"A Uniform Resource Identifier (URI) as defined by STD 66.
Objects using this TEXTUAL-CONVENTION MUST be in US-ASCII
encoding, and MUST be normalized as described by RFC 3986
Sections 6.2.1, 6.2.2.1, and 6.2.2.2. All unnecessary
percent-encoding is removed, and all case-insensitive
characters are set to lowercase except for hexadecimal
digits, which are normalized to uppercase as described in
Section 6.2.2.1.
The purpose of this normalization is to help provide unique
URIs. Note that this normalization is not sufficient to
provide uniqueness. Two URIs that are textually distinct
after this normalization may still be equivalent.
Objects using this TEXTUAL-CONVENTION MAY restrict the
schemes that they permit. For example, 'data:' and 'urn:'
schemes might not be appropriate.
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RFC 5017 URI TC MIB September 2007
A zero-length URI is not a valid URI. This can be used to
express 'URI absent' where required, for example when used
as an index field.
STD 66 URIs are of unlimited length. Objects using this
TEXTUAL-CONVENTION impose a length limit on the URIs that
they can represent. Where no length restriction is
required, objects SHOULD use the 'Uri' TEXTUAL-CONVENTION
instead. Objects used as indices SHOULD subtype the 'Uri'
TEXTUAL-CONVENTION."
REFERENCE "RFC 3986 STD 66 and RFC 3305"
SYNTAX OCTET STRING (SIZE (0..1024))
END
5. Security Considerations
See also the Security Considerations of STD 66 [RFC3986].
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
URI-TC-MIB is rooted under the mib-2 subtree. IANA has assigned {
mib-2 164 } to the URI-TC-MIB module specified in this document.
7. Acknowledgements
This module was generated by editing together contributions from
Randy Presuhn, Dan Romascanu, Bill Fenner, Juergen Schoenwaelder, and
others.
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.
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RFC 5017 URI TC MIB September 2007
[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.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66,
RFC 3986, January 2005.
8.2. Informative References
[RFC3305] Mealling, M. and R. Denenberg, "Report from the Joint W3C/
IETF URI Planning Interest Group: Uniform Resource
Identifiers (URIs), URLs, and Uniform Resource Names
(URNs): Clarifications and Recommendations", RFC 3305,
August 2002.
[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 5017 URI TC MIB September 2007
Full Copyright Statement
Copyright (C) The IETF Trust (2007).
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contained in BCP 78, and except as set forth therein, the authors
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