A URN Namespace of Object Identifiers
Encoding Object Identifiers as Uniform Resource Names.
Mealling, M., "A URN Namespace of Object Identifiers", RFC 3001, DOI 10.17487/RFC3001, November 2000, <https://www.rfc-editor.org/info/rfc3001>.
@misc{rfc3001,
series = {Request for Comments},
number = 3001,
howpublished = {RFC 3001},
publisher = {RFC Editor},
doi = {10.17487/RFC3001},
url = {https://www.rfc-editor.org/info/rfc3001},
author = {M. Mealling},
title = {{A URN Namespace of Object Identifiers}},
pagetotal = 5,
year = 2000,
month = nov,
} RFC text
Contents
Network Working Group M. Mealling
Request for Comments: 3001 Network Solutions, Inc.
Category: Informational November 2000
A URN Namespace of Object Identifiers
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2000). All Rights Reserved.
Abstract
This document describes a Uniform Resource Names (URN) namespace that
contains Object Identifiers (OIDs).
1. Introduction
An Object Identifier is a series of digits delimited in some way.
The rules roughly state that once an entity is assigned an Object
Identifier (OID) it has sole discretion to further subdelegate off of
that OID. Some examples of OIDs include:
o 1.3.6.1 - the Internet OID
o 1.3.6.1.4.1 - IANA-assigned company OIDs, used for private MIBs
and such things
o 1.3.6.1.2.1.27 - The Applications MIB
o 0.9.2342.19200300.100.4 - Object ID's used in the directory pilot
project to identify X.500 Object Classes. Mostly defined in RFC-
1274.
This document specifies the "oid" URN namespace [1]. This namespace
is for encoding an Object Identifier as specified in ASN.1 [2] as a
URI.
The namespace specification is for a formal namespace.
2. Specification Template
Namespace ID:
"oid" requested.
Registration Information:
Registration Version Number: 1
Registration Date: 2000-04-30
Declared registrant of the namespace:
I need help here. I'm not comfortable being the 'registrant'. So
who do I actually put here?
The ISO/IEC Joint Technical Committee 1 - SubCommittee 6 The
actual real authority is the ASN.1 specification itself but at
present SC6 is the committee that has the authority to interpret
what that means.
Declaration of structure:
The NSS portion of the identifier follows the string encoding
rules found in RFC 1778 Section 2.15 [3] which specifies a series
of digits separated by a period with the most significant digit
being at the left and the least significant being at the right.
No changes are anticipated since Object Identifiers are fairly
simple and have been standardized with no changes for many years.
Relevant ancillary documentation:
Relevant documentation can be found in X.660/Amd 2 | ISO/IEC
9834-1/Amd 2 [2].
Identifier uniqueness considerations:
The rules for assignment of OIDs requires that each OID be unique
to the OID space and that it cannot be reassigned or reused. By
reference this URN namespace inherents those rules.
Identifier persistence considerations:
The rules concerning the use of OIDs requires that they not be
reused once assigned. By reference this URN namespace inherents
those rules.
Process of identifier assignment:
Once an OID is assigned to some entity, that entity can then
create and assign new OIDs below that particular OID. There are
multiple entities that assign new OIDs to the general public. The
top three levels are pre-assigned as follows:
0 - ITU-T assigned
1 - ISO assigned
2 - Joint ISO/ITU-T assignment
several assigned OIDs that are of importance to the Internet are:
1.3.6.1 - the Internet OID
1.3.6.1.4.1 - IANA-assigned company OIDs, used for private
MIBs and such things
Process of identifier resolution:
At this time no resolution mechanism is defined.
Rules for Lexical Equivalence:
OIDs are composed of multiple occurrences of digits and the "."
character. Lexical equivalence is achieved by exact string match.
Conformance with URN Syntax:
There are no additional characters reserved.
Validation mechanism:
None.
Scope:
Global
3. Examples
The following examples are taken from the example OIDs from the
Introduction:
urn:oid:1.3.6.1
urn:oid:1.3.6.1.4.1
urn:oid:1.3.6.1.2.1.27
URN:OID:0.9.2342.19200300.100.4
4. Security Considerations
None not already inherent to using unverifiable OIDs
5. Acknowledgements
The author would like to thank Harald Alvestrand for the use of his
OID database as a source for examples and references.
References
[1] Moats, R., "URN Syntax", RFC 2141, May 1997.
[2] CCITT, "Specification of Basic Encoding Rules for Abstract
Syntax Notation One (ASN.1)", CCITT Recommendation X.209,
January 1988.
[3] Howes, T., Kille, S., Yeong, W. and C. Robbins, "The String
Representation of Standard Attribute Syntaxes", RFC 1778, March
1995.
Author's Address
Michael Mealling
Network Solutions, Inc.
505 Huntmar Park Drive
Herndon, VA 22070
US
Phone: +1 770 935 5492
EMail: michaelm@netsol.com
URI: http://www.netsol.com
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Acknowledgement
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AI ELI5
On this page
§1What Are Object Identifiers?
An Object Identifier (OID) is a series of numbers separated by dots, such as 1.3.6.1 or 1.3.6.1.4.1. They are defined in ASN.1 and are used for naming things in network management, directory services, and cryptography. Once an entity is assigned an OID, that entity can create new OIDs under it (subdelegation).
The top three levels are pre-assigned: 0 is for ITU-T, 1 is for ISO, and 2 is for joint ISO/ITU-T assignments. Important OIDs include 1.3.6.1 (the Internet OID) and 1.3.6.1.4.1 (IANA-assigned company OIDs used in network management).
Some things in computer networks have names that are just numbers with dots, like 1.3.6.1.4.1. These are called Object Identifiers, and people use them in management systems.
§2The OID URN Namespace
RFC 3001 defines the "oid" URN namespace so that Object Identifiers can be written as Uniform Resource Names in a standard way. An OID like 1.3.6.1.4.1 becomes urn:oid:1.3.6.1.4.1. The namespace specification uses the string encoding rules from RFC 1778, which require digits separated by periods with the most significant digit on the left.
The namespace guarantees uniqueness and persistence: OIDs cannot be reused once assigned, and by reference, the URN namespace inherits those rules. This means urn:oid identifiers are guaranteed to be permanent and unique.
By writing OID numbers in a URN (web-style name), they can be used in modern Internet protocols and look like regular web names instead of just dots and numbers.
§3Examples and Use
The RFC provides examples: urn:oid:1.3.6.1 is the Internet OID, urn:oid:1.3.6.1.4.1 is for private company MIBs, urn:oid:1.3.6.1.2.1.27 is the Applications MIB, and urn:oid:0.9.2342.19200300.100.4 represents an object class from the X.500 directory pilot project.
The namespace is global and formal. At the time of this RFC, no central resolution mechanism was defined (you cannot look up urn:oid names the way you can look up domain names), but the URN form provides a standard way to reference OIDs in specifications and protocols.
Here are some examples of how to write real OIDs as URNs: urn:oid:1.3.6.1 for the Internet, urn:oid:1.3.6.1.4.1 for companies. They look like web addresses but are actually OID numbers.