ISO/IEC 29168-1:2011

Information technology — Open systems interconnection — Part 1: Object identifier resolution system

ISO/IEC 29168-1:2011 specifies the object identifier (OID) resolution system (ORS), including the overall architecture and a DNS-based resolution mechanism. It specifies the means for inserting any application-defined information associated with an OID node into the domain name system (DNS) and the means of retrieval of that information using the ORS. It does not restrict the number of applications it can support. It specifies the required operation of an ORS client, including the mapping of an OID-IRI (internationalized resource identifier) value by the ORS client into a DNS name to produce a DNS query for the specified application information and the processing of any returned information. The ORS has no role in the allocation or registration of OID nodes. The required behaviour of an ORS client is specified, but the interfaces to it are specified only in terms of the semantics of the interaction. A bit-level application program interface is platform- and software-dependent, and is not in the scope of ISO/IEC 29168-1:2011. It does not include a tutorial or complete specification on the management of DNS zone files; it specifies (only) the DNS resource records that need to be inserted in the zone files in order to support ORS access to the information associated with an OID node. ISO/IEC 29168-1:2011 specifies required DNS zone file resource records, and prohibits the use of other resource records of a similar form but with different semantics (in DNS zone files in the .oid res.org domain). It does not otherwise restrict the general use of DNS zone files.

Technologies de l'information — Interconnexion de systèmes ouverts (OSI) — Partie 1: Système de résolution d'identificateur d'objet

General Information

• Status: Withdrawn
• Publication Date: 11-Sep-2011
• ICS: 35.080 - Software
• Technical Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Drafting Committee: ISO/IEC JTC 1/SC 6 - Telecommunications and information exchange between systems
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 17-Mar-2023

Relations

• Revised: ISO/IEC 29168-1:2023 - Information technology — Open systems interconnection — Part 1: Object identifier resolution system
• Effective Date: 17-Jul-2021

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 29168-1


Information technology — Open systems
interconnection —
Part 1:
Object identifier resolution system
Technologies de l'information — Interconnexion de systèmes ouverts
(OSI) —
Partie 1: Système de résolution d'identificateur d'objet





Reference number
ISO/IEC 29168-1:2011(E)
©
ISO/IEC 2011

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ISO/IEC 29168-1:2011(E)

COPYRIGHT PROTECTED DOCUMENT


©  ISO/IEC 2011
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ISO/IEC 29168-1:2011(E)


CONTENTS
Page
1 Scope . 1
2 Normative references . 1
2.1 Identical Recommendations | International Standards . 1
2.2 Additional references . 1
3 Definitions . 2
3.1 Imported definitions . 2
3.2 Additional definitions . 2
4 Abbreviations and acronyms . 3
5 OID resolution system architecture . 4
5.1 OID resolution process . 4
5.2 Interactions between components in the general OID resolution process . 4
6 DNS zone files for the .oid-res.org domain . 5
6.1 Overview . 5
6.2 Requirements and restrictions on DNS zone files in the .oid-res.org domain . 6
6.3 Use of DNS resource records for ORS services . 6
6.4 Security considerations . 7
7 Operation of an ORS client . 7
7.1 Functional interfaces . 7
7.2 Processing a query . 7
7.3 Converting an OID-IRI value to an FQDN . 7
7.4 Processing DNS results . 8
7.5 Security considerations . 8
8 Requirements on ORS service specifications . 8
8.1 Specification of NAPTR information . 8
8.2 Recommendations for ORS application processing . 8
Annex A – Assigned ORS service types . 9
Annex B – Specification of the OID canonicalization (COID) ORS service . 10
Annex C – Specification of the child information (CINF) ORS service . 11
C.1 General . 11
C.2 CINF XML file . 11
Annex D – Specification of the registration information (RINF) ORS service . 13
D.1 General . 13
D.2 RINF XML file . 13
Annex E – Specification of the module information (MINF) ORS service . 15
Annex F – Description of use cases . 16
F.1 OID canonicalization (COID) ORS service . 16
F.2 Child information (CINF) ORS service . 16
F.3 Registration information (RINF) ORS service . 16
F.4 Module information (MINF) ORS service . 16
Annex G – Examples of ORS operation . 17
G.1 Example of DNS zone files for the ORS . 17
G.2 Examples of NAPTR resource records . 17
Annex H – History of object identifiers (OIDs) . 18
Annex I – Bibliography . 19

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ISO/IEC 29168-1:2011(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form
the specialized system for worldwide standardization. National bodies that are members of ISO or IEC participate in the
development of International Standards through technical committees established by the respective organization to deal
with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest.
Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International Standards
adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the national bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO
and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 29168-1 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee
SC 6, Telecommunications and information exchange between systems in collaboration with ITU-T. The identical text is
published as Rec. ITU-T X.672 (08/2010).
ISO/IEC 29168 consists of the following parts, under the general title Information technology — Open systems
interconnection:
 Part 1: Object identifier resolution system
 Part 2: Procedures for the object identifier resolution system operational agency

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ISO/IEC 29168-1:2011(E)

Introduction
This Recommendation | International Standard specifies the object identifier resolution system. This provides the return
(using an ORS client) of information associated with an OID node.
It uses a mapping of the International Object Identifier tree naming scheme (using OID-IRI values) onto the DNS
naming scheme (see 7.3).
This Recommendation | International Standard specifies requirements on the management of DNS zone files that are
mapped from ORS-supported OID nodes to provide (standardized) information related to an International Object
Identifier tree node for a variety of applications, and on the behaviour of an ORS client that interacts with the DNS
system to obtain that information and provide it to an application.
Six requirements emerged in the mid/late-2000s:
– an application to be able to translate any OID-IRI value into a canonical OID-IRI (a unique string of
numeric Unicode labels that would identify a node): the COID ORS service, supporting IRI comparison
of names in the IETF "oid" IRI scheme (see Annex B);
– an application to determine child information from an OID node: the CINF service (see Annex C);
– an application to obtain registration information (such as contact information about the owner of the OID
node, and how to request a child node, etc.): the RINF service (see Annex D);
– an application to obtain a reference to the ASN.1 module (if any) associated with a node: the MINF
service (see Annex E);
– support for access to multimedia information (triggered by tag-based identification) using the ORS;
– support for access to information contained in an OID node that relates to cybersecurity features.
There are probably other applications that will require further information (specified by an application standard)
contained in an ORS-supported OID node and accessible by the ORS.
To meet these needs, it was decided to map the OID tree into a part of the DNS tree (see IETF RFC 1035), with the root
of the OID tree mapped into .oid-res.org (see 7.3).
The mapping is from any OID-IRI value that identifies an International OID node into a DNS name (in the .oid-res.org
domain). The information about an ORS-supported OID node is inserted into DNS zone files and can then be retrieved
by any ORS client (running on any computer system with DNS access), using any of the OID-IRI identifications for
that International Object Identifier tree node.
The associated information is specified by those applications that choose to use the ORS. The requirements on such
applications are included in this Recommendation | International Standard. Some application specifications are included
as normative annexes to this Recommendation | International Standard. Others are specified externally.
All DNS zone files for the .oid-res.org domain correspond to ORS-supported OID nodes, but not all DNS names
algorithmically mapped from an OID-IRI will be present in the DNS. All DNS zone files in the .oid-res.org domain are
required to confirm to this Recommendation | International Standard.
Information for an International OID tree node (for each application) is specified by the owner of that node, and
determines the appropriate configuration of DNS zone files, in accordance with the specification for each ORS service
(see Annex A), and would be retrieved by an application using a local ORS client implementation interacting with a
local DNS client (see clause 7). The information would be included in NAPTR resource records, qualified by the ORS
service type.
An ORS client takes as input any OID-IRI value, together with an ORS service type. It will return node information for
that OID-IRI value and ORS service type (based on the configuration of the DNS zone files, and particularly of NAPTR
resource records). Each resource record will consist of one or more pieces of information together with the requested
ORS service type.
The procedures for the appointment of the ORS operational agency are contained in ISO/IEC 29168-2. These
procedures involve only ISO/IEC for appointment and contractual purposes. They do not have any ITU-T involvement.
Clause 5 provides an overview of the OID resolution system architecture and its interaction with the DNS.
Clause 6 specifies the requirements and restrictions on DNS zone files in the .oid-res.org domain in order to support
navigation to DNS names mapped from the International OID tree (including the use of long arcs) and the provision of
information needed for the ORS resolution process using any specified ORS service type.
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ISO/IEC 29168-1:2011(E)

NOTE – This Specification relates only to the use of DNAME DNS resource records and NAPTR resource records using a
service field commencing "ORS+". Use of other DNS resource records are not in the scope of this Recommendation |
International Standard, and are neither forbidden (except when they would conflict with the use for the ORS) nor are they

required.
Clause 7 specifies the operation of an ORS client, including the mapping of an OID-IRI value into a DNS name.
Clause 8 specifies the requirements on an ORS application specification, including specification of NAPTR information
and recommendations on ORS application processing.
Security considerations are discussed and specified in 5.2.3 to 5.2.6, 6.4, 7.5 and 8.2.2.
Annex A (normative) specifies the assigned ORS service types at the time of publication of this Recommendation |
International Standard.
Annex B (normative) specifies the COID service.
Annex C (normative) specifies the requirements for the CINF service.
Annex D (normative) specifies the requirements for the RINF service.
Annex E (normative) specifies the requirements for the MINF service.
Annex F (informative) provides a description of the use cases for the ORS, referencing each application that has a
specified ORS service type (see Annex A).
Annex G (informative) provides examples of possible DNS zone files to support the ORS and additional examples of
NAPTR resource records.
Annex H (informative) provides a short history of the development of the International OID tree.
Annex I (informative) provides bibliographic references.
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ISO/IEC 29168-1:2011 (E)
INTERNATIONAL STANDARD
RECOMMENDATION ITU-T
Information technology – Open systems interconnection –
Object identifier resolution system
1 Scope
This Recommendation | International Standard specifies the OID resolution system, including the overall architecture
and a DNS-based resolution mechanism.
It specifies the means for inserting any application-defined information associated with an OID node into the DNS (see
clause 6) and the means of retrieval of that information using the ORS (see clause 7).
It does not restrict the number of applications it can support.
It specifies the required operation of an ORS client (see clause 7), including the mapping of an OID-IRI value by the
ORS client into a DNS name to produce a DNS query for the specified application information and the processing of
any returned information. The ORS has no role in the allocation or registration of OID nodes.
The required behaviour of an ORS client is specified, but the interfaces to it are specified only in terms of the semantics
of the interaction. A bit-level application program interface is platform and software dependent, and is not in the scope
of this Recommendation | International Standard.
It does not include a tutorial or complete specification on the management of DNS zone files (for that, see
IETF RFC 1035 and IETF RFC 3403); it specifies (only) the DNS resource records (see 6.3) that need to be inserted in
the zone files in order to support ORS access to the information associated with an OID node.
This Recommendation | International Standard specifies required DNS zone file resource records, and prohibits the use
of other resource records of a similar form but with different semantics (in DNS zone files in the .oid-res.org domain) –
see 6.2. It does not otherwise restrict the general use of DNS zone files.
2 Normative references
The following Recommendations and International Standards contain provisions which, through reference in this text,
constitute provisions of this Recommendation | International Standard. At the time of publication, the editions indicated
were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on this
Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent
edition of the Recommendations and Standards listed below. Members of IEC and ISO maintain registers of currently
valid International Standards. The Telecommunication Standardization Bureau of the ITU maintains a list of currently
valid ITU-T Recommendations.
2.1 Identical Recommendations | International Standards
– Recommendation ITU-T X.509 (2005) | ISO/IEC 9594-8:2005, Information technology – Open Systems
Interconnection – The Directory: Public-key and attribute certificate frameworks.
– Recommendations ITU-T X.660 series | ISO/IEC 9834 multi-part standard, Information technology –
Open Systems Interconnection – Procedures for the operation of OSI Registration Authorities.
– Recommendations ITU-T X.680 (2008) series | ISO/IEC 8824:2008 multi-part standard, Information
technology – Abstract Syntax Notation One (ASN.1).
– Recommendation ITU-T X.693 (2008) | ISO/IEC 8825-4:2008, Information technology – ASN.1
encoding rules: XML Encoding Rules (XER).
2.2 Additional references
– IETF RFC 1034 (1987), Domain names – Concepts and facilities.
– IETF RFC 1035 (1987), Domain names – Implementation and specification.
– IETF RFC 3403 (2002), Dynamic Delegation Discovery System (DDDS) Part Three: The Domain Name
System (DNS) Database.
 Rec. ITU-T X.672 (08/2010) 1

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ISO/IEC 29168-1:2011 (E)
– IETF RFC 3454 (2002), Preparation of Internationalized Strings ("stringprep").
– IETF RFC 3490 (2003), Internationalizing Domain Names in Applications (IDNA).
– IETF RFC 3492 (2003), Punycode: A Bootstring encoding of Unicode for Internationalized Domain
Names in Applications (IDNA).
– IETF RFC 4033 (2005), DNS Security Introduction and Requirements.
– IETF RFC 5155 (2008), DNS Security (DNSSEC) Hashed Authenticated Denial of Existence.
  NOTE – It is recommended that the IETF RFC index be consulted for updates to the RFCs listed above.
– Unicode 5.2 (2002), The Unicode Standard, Version 3.2.0, The Unicode Consortium (Reading, MA,
Addison-Wesley).
– W3C, HTML 4.01 Specification, W3C Recommendation 24 December 1999,
http://www.w3.org/TR/1999/REC-html401-19991224.
3 Definitions
For the purposes of this Recommendation | International Standard, the following definitions apply.
3.1 Imported definitions
This Recommendation | International Standard uses the following terms defined in Rec. ITU-T X.660 |
ISO/IEC 9834-1:
a) object identifier;
b) integer-valued Unicode label;
c) International Object Identifier tree;
d) long arc;
e) OID internationalized resource identifier;
f) Registration Authority;
g) Unicode label.
3.2 Additional definitions
3.2.1 application-specific OID resolution process: Actions by an application to retrieve application-specific
information from the information returned by the general OID resolution process.
3.2.2 canonical form (of an OID-IRI): A form which uses only integer-valued Unicode labels.
NOTE – OID-IRI is an ASN.1 type defined in Rec. ITU-T X.680 | ISO/IEC 8824-1. The term OID-IRI value refers to the ASN.1
value notation that is the same as the IANA "oid:" IRI/URI scheme, with the omission of the initial "oid:".
3.2.3 DNS delegation name (DNAME): A DNS resource record used to create an alias for a domain name and all
of its sub-domains.
3.2.4 DNS-mapped name: The result of transforming an OID-IRI value to an FQDN (see 7.3).
NOTE – The DNS-mapped name may or may not exist in the DNS. If it does not, then an ORS query will result in an error
message (see 7.4), and the node identified by the OID-IRI is not ORS-supported.
3.2.5 DNS name server (NS): A DNS resource record providing the authoritative name server for a domain.
3.2.6 DNS resource record: A component of a DNS zone file.
3.2.7 DNS zone file: A text file that describes a portion of the DNS.
NOTE – The format of a DNS zone file is defined in IETF RFC 1035, section 5 and IETF RFC 1034, section 3.6.1.
3.2.8 fully qualified domain name: The name used in a DNS look-up operation (see IETF RFC 1594).
3.2.9 general OID resolution process: That part of the ORS where an ORS client obtains information from the
DNS (recorded in a zone file) about any specified OID and returns it to an application.
3.2.10 operational agency procedures: The specification of the actions required by the .oid-res.org operational
agency.
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ISO/IEC 29168-1:2011 (E)
3.2.11 NAPTR resource record: A DNS resource record used to store rules which can be retrieved by a DNS look-
up for use by an application.
3.2.12 OID resolution process: Process which provides information associated with an OID.
NOTE – This information can be application-specific (see Figure 1 and the annexes).
3.2.13 OID resolution system: Implementation of the OID resolution process in accordance with this
Recommendation | International Standard.
3.2.14 .oid-res.org operational agency: Organization that manages the DNS server for .oid-res.org and some
subordinate nodes.
3.2.15 ORS client: Entity that interfaces between an application and a DNS client.
3.2.16 ORS service type: A character string (used in NAPTR resource records) that identifies an ORS service (see
Annex A).
3.2.17 ORS-supported OID node: An OID node for which the DNS-mapped names for all of the OID-IRI values
that identify the OID node exist in the DNS, and have all necessary DNS zone files configured as specified in this
Recommendation | International Standard, including mandatory requirements for all ORS services (see Annex A).
NOTE 1 – The canonical OID service specified in Annex B requires the presence of a NAPTR record in the associated DNS zone
file.
NOTE 2 – The .oid-res.org operational agency is required by the operational procedures to provide ORS-support for all the OID
nodes listed in those procedures. ORS support for nodes beneath these depends on agreements between that OID node and its
parent.
4 Abbreviations and acronyms
This Recommendation uses the following abbreviations and acronyms:
AD Authenticated Data
CD Checking Disabled
CINF Child Information
COID Canonical OID
CYBEX Cybersecurity Exchange Information
DNAME (DNS) Delegation Name
DNS Domain Name System
DO DNS Security OK
FQDN Fully Qualified Domain Name
MINF Module Information
NAPTR (DNS) Naming Authority Pointer
NS (DNS) Name Server
OID Object Identifier
OID-IRI OID Internationalized Resource Identifier (see Note in 3.2.2)
ORS OID Resolution System
RCODE (DNS) Return Code
RINF Registration Information
TINF Tag-based multimedia access Information
URL Uniform Resource Locator
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ISO/IEC 29168-1:2011 (E)
5 OID resolution system architecture
5.1 OID resolution process
5.1.1 The OID resolution process is illustrated in Figure 1. It consists of two processes: a general OID resolution
process and an application-specific OID resolution process.
5.1.2 The general OID resolution process uses the DNS (see IETF RFC 1035) and DNS resource records (see
IETF RFC 3403). It involves an interaction between the application and an ORS client to retrieve information (specified
by that application) from the DNS system. The general OID resolution process normally returns a URL for a document,
a canonical OID-IRI or a DNS name, but there is no restriction on what could be returned. This is usually followed by
an application-specific OID resolution process, where the application uses the information obtained from the general
resolution process to obtain the final information required by the application.
NOTE – For some services, for example the COID service (see Annex B), the information returned from the ORS client will be
sufficient, and there will be no application-specific OID resolution process.
OID-IRI + ORS service type
+ security flag
General OID resolution
process DNS NAPTR resource records
DNS with zone files
(1)
for ORS support
Application
(2) Application-specific request
Application-specific OID Application-specific
Application-specific information
resolution process servers
X.672(10)_F01

Figure 1 – OID resolution process
5.2 Interactions between components in the general OID resolution process
5.2.1 Figure 2 shows the functional interfaces between the components of the general OID resolution process and
the semantics of the interactions. Bit-level encoding of these interfaces and interactions is platform and software
dependent, and is not in the scope of this Recommendation | International Standard. The realization of this architecture
in hardware or software and its partitioning into separate modules is not constrained by this Recommendation |
International Standard.
ORS client interface DNS client interface
(1) OID-IRI + ORS service type
(2) OID-IRI as an FQDN
+ security flag + security parameters
Application
ORS client DNS client DNS
(3) 0 or more NAPTR
(4) 0 or more of (ORS
resource records or error
information of the specified
service type + preference
values) eror ror
X.672(10)_F02

Figure 2 – Components of the general OID resolution system
5.2.2 There are three main actors: the application, an ORS client, and the DNS system.
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ISO/IEC 29168-1:2011 (E)
5.2.3 (Step 1) The application makes a request to the ORS client for information about an OID, giving one of the
OID-IRI values that identifies that OID node and the ORS service type that it is interested in (see Annex A). It also sets
the "security flag". This determines whether DNSSEC – if available – is to be used (see 5.2.4).
NOTE 1 – The application has to trust the ORS client and the DNS client to pass on the security flag setting, and for the DNS
servers to correctly implement IETF RFC 4033 and IETF RFC 5155 (NSEC3). If the application does not trust the ORS client or
the DNS client that it is using, it should not set the security flag, as it will not provide any security benefit.
NOTE 2 – It is a requirement of the operational agency procedures that the .oid-res.org operational agency provides full support
for security as required by IETF RFC 4033 and IETF RFC 5155.
5.2.4 (Step 2) The ORS client transforms the OID-IRI value into an FQDN as specified in 7.3 and sends a query
request to a DNS client for NAPTR resource records containing the requested ORS information type, as specified in
7.2. If the security flag is 1, then the DO parameter of the DNS query request shall be 1 and the CD parameter shall be 0
(specified in IETF RFC 4033); otherwise, the DO and CD parameters are not passed.
5.2.5 (Step 3) The DNS client returns either zero or more NAPTR resource records, or an error (specified as a non-
zero DNS RCODE – see IETF RFC 1035).
5.2.6 (Step 4) The ORS client processes the NAPTR resource records as specified in 7.4 and returns to the
application zero or more information fields with preference values, and the DNS RCODE (the appropriate interpretation
of the RCODE is given in Table 1). If the security flag was 1 (see 5.2.4), then only NAPTR resource records with AD
flag (specified in IETF RFC 4033) set to 1 are returned; otherwise, all NAPTR resource records are returned.
Table 1 – Interpretation of DNS
...