Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


Network Working Group T. Edwards Request for Comments: 5119 FOX Category: Informational February 2008

            A Uniform Resource Name (URN) Namespace for
   the Society of Motion Picture and Television Engineers (SMPTE)

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.


 This document describes a Uniform Resource Name (URN) namespace for
 the Society of Motion Picture and Television Engineers (SMPTE) for
 naming persistent resources that SMPTE produces or manages.  A
 subnamespace for Universal Labels is specifically described.

Table of Contents

 1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  2
 2.  URN Namespace Definition Template  . . . . . . . . . . . . . .  2
 3.  Examples . . . . . . . . . . . . . . . . . . . . . . . . . . .  6
 4.  Security Considerations  . . . . . . . . . . . . . . . . . . .  6
 5.  Namespace Considerations and Community Considerations  . . . .  6
 6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  7
 7.  SMPTE Registration Authority (Informative) . . . . . . . . . .  7
 8.  References . . . . . . . . . . . . . . . . . . . . . . . . . .  7
   8.1.  Normative References . . . . . . . . . . . . . . . . . . .  7
   8.2.  Informative References . . . . . . . . . . . . . . . . . .  7

Edwards Informational [Page 1] RFC 5119 SMPTE URN Definition February 2008

1. Introduction

 SMPTE (the Society of Motion Picture and Television Engineers) is an
 internationally-recognized standards-developing organization.
 Headquartered and incorporated in the United States of America, SMPTE
 has members in over 80 countries on six continents.  SMPTE's
 Engineering Documents, including Standards, Recommended Practices,
 and Engineering Guidelines, are prepared by SMPTE's Technology
 Committees.  Participation in these Committees is open to all with a
 bona fide interest in a committee's work.  SMPTE cooperates closely
 with other standards-developing organizations, including ISO, the
 IEC, and the ITU.  Also, the SMPTE Registration Authority maintains a
 registry of Universal Labels (ULs) used in identifying the type and
 encoding of data within data streams associated with audio-visual
 SMPTE would like to assign unique, permanent, and location-
 independent names using URNs for resources that SMPTE produces or
 This namespace specification is for a formal namespace.

2. URN Namespace Definition Template

 The following template is provided in accordance with [RFC3406].
    Namespace ID:
    Registration Information:
       Version: 2
       Date: 2007-07-08
    Declared registrant of the namespace:
       Registering Organization: Society of Motion Picture and
                                 Television Engineers
          Address: 3 Barker Avenue - 5th Floor
                   White Plains, NY 10601 USA
       Designated Contact Person: Director of Engineering
          Phone: +1 (914) 761-1100

Edwards Informational [Page 2] RFC 5119 SMPTE URN Definition February 2008

    Declaration of structure:
       The Namespace Specific String (NSS) of all URNs that use the
       "smpte" NID shall be conformant to the URN syntax requirements
       defined in [RFC2141].
       URNs for the "urn:smpte" namespace shall follow the structure
       defined in [SMPTE2029].
       SMPTE (or it successor) may add additional subnamespaces
       in the future.  Any system that deals with URNs for the
       "urn:smpte" namespace should be written with the awareness
       that this could occur at any time.
       For informative purposes, the identifier structure described
       using ABNF (according to [RFC4234]) is as follows:
          ;start ABNF notation
          URN = "urn:" NID NSS
          NID = "smpte:"
          NSS = UL-NSS / other-NSS
          UL-NSS = "ul:" UL
          DOT = %x2E ; period
          QUADBYTE = 4BYTE
          BYTE = 2HEXDIG
          other-NSS = 1*(DIGIT / ALPHA / "-"/":")
          ; other-NSS that conforms with [RFC2141] for future
          ;end ABNF notation
    Relevant ancillary documentation:
       The structure for URNs in the "urn:smpte" namespace are defined
       in [SMPTE2029].

Edwards Informational [Page 3] RFC 5119 SMPTE URN Definition February 2008

       The values of ULs in the "urn:smpte:ul" subnamespace shall be
       constrained as defined in [SMPTE298M].  Details regarding the
       use of ULs as keys in key-length-value (KLV) coding, including
       how to determine in which SMPTE registry a SMPTE-administered
       UL may be found, are described in [SMPTE336M].
    Identifier uniqueness considerations:
       [SMPTE2029] states that "All URNs in the SMPTE namespace shall
       conform to IETF RFC 3406.  In particular, URNs in the SMPTE
       namespace shall not be re-assigned, and URNs shall continue to
       be valid, even if the owners or registrants of the SMPTE
       resources identified by the URNs are no longer members or
       customers of SMPTE.  There need not be resolution of such URNs,
       but they shall not resolve to false or stale information."
       Additionally, the rules for assignment of SMPTE-administered
       ULs requires that each UL be unique to the UL space and that it
       cannot be reassigned or reused.
       It should be noted that [SMPTE298M] states that "A universal
       label shall be an 'object identifier' as specified by ISO/IEC
       8824-1," ([ISO8824-1]) although the SMPTE Universal Label
       representation is a specialized one that carries additional
       semantics over the OID representation of a URN OID ([RFC3061]).
       SMPTE will work to ensure that all current and future
       "urn:smpte" subnamespaces contain unique identifiers.
    Identifier persistence considerations:
       SMPTE-administered ULs may occasionally be deleted through
       SMPTE procedures.  Regardless, even after a UL has been
       deleted, it will not be reused.  Revisions to ULs will result
       in the creation of a new UL and the deletion of the old one.
       The persistence of URNs in future "urn:smpte" subnamespaces
       will be defined by SMPTE Standards.
    Process of identifier assignment:
       Assignment of URNs in the SMPTE NID is limited to SMPTE and
       those authorities that are specifically designated by SMPTE.
       SMPTE may designate portions of its namespace for assignment by
       other parties.

Edwards Informational [Page 4] RFC 5119 SMPTE URN Definition February 2008

       Due process is followed by committees in the development of
       SMPTE documents.  Some types of Universal Label registrations
       and other registrations may require a fee to be paid to SMPTE.
       All classes of SMPTE-administered ULs require for registration
       the name and address of the applicant.  Some classes of labels
       also require the submission of supporting technical
       documentation for the label and may require a due process
       evaluation through the SMPTE Engineering Committee process.
    Process for identifier resolution:
       SMPTE-administered ULs are resolved through publications of the
       SMPTE Registration Authority.  Currently, publication of
       SMPTE-administered ULs are made through a Metadata Dictionary
       as specified in [RP210] and through the SMPTE Labels Registry
       as specified in [RP224], both of which are currently available
       online at
       SMPTE expects to develop and maintain "URN catalogs" that map
       all future assigned URNs in the "urn:smpte" namespace to
       Uniform Resource Locators (URLs) to enable Web-based resolution
       of named resources.
    Rules for Lexical Equivalence:
       Lexical equivalence of URNs in the "urn:smpte:ul" subnamespace
       is defined by case-insensitive string match.
       Lexical equivalence of URNs in additional subnamespaces of
       "urn:smpte:" will be specified by SMPTE in the defining
       document; in the absence of such specification, lexical
       equivalence of URNs in the "urn:smpte:" namespace outside of
       the "urn:smpte:ul" subnamespace is defined by exact string
       match, according to [RFC2141].
    Conformance with URN Syntax:
       No special considerations beyond the syntax herein described.
    Validation mechanism:

Edwards Informational [Page 5] RFC 5119 SMPTE URN Definition February 2008

3. Examples

 Currently, only a "urn:smpte:ul" subnamespace is defined.  This is
 the subnamespace for SMPTE Universal Labels [SMPTE298M].  SMPTE may
 add additional subnamespaces in the future.
 The following examples are not guaranteed to be real and are provided
 for illustrative purposes only.

4. Security Considerations

 The SMPTE URN Namespace ID shares the security considerations
 outlined in [RFC3406], but has no other known security

5. Namespace Considerations and Community Considerations

 SMPTE is an internationally-recognized standards-developing
 organization.  As part of this effort, SMPTE also registers items
 such as Universal Labels through the SMPTE Registration Authority.
 The SMPTE namespace provides a uniform, unique, and effective way to
 communicate resource names for these items, which can be used by the
 motion imaging industry community.  This namespace is also intended
 to be a useful mechanism to provide both human and automated access
 to these resources through online systems.
 The individual URNs in the namespace shall be assigned through the
 process of development of documents by SMPTE, through definition by
 SMPTE standards, or through the registration of Universal Labels or
 other items by the SMPTE Registration Authority.
 RFC 3406 states that a URN registration RFC must include a 'Namespace
 Considerations' section, which outlines the perceived need for a new
 namespace.  There are four areas where existing URN namespaces fall
 short of the requirements for a SMPTE URN namespace.
    URN assignment procedures: URNs for resources defined by SMPTE
    standards must be assigned exclusively by SMPTE or its delegates
    to ensure the integrity of the standards process.  No other
    existing URN namespace has URNs assigned and managed by SMPTE.
    URN resolution: URNs assigned by SMPTE standards must be resolved
    by SMPTE mechanisms such as the SMPTE Registration Authority to

Edwards Informational [Page 6] RFC 5119 SMPTE URN Definition February 2008

    ensure the integrity of the standards process.  This resolution
    may require the reference of databases only maintained by SMPTE.
    Types of resources to be identified: Many resources defined by
    SMPTE standards (such as Universal Labels) have no adequate
    existing URN representation.
    Types of services to be supported: SMPTE expects to establish Web
    services for the automated resolution of resources defined by
    SMPTE standards utilizing the SMPTE URN namespace.

6. IANA Considerations

 This document defines a URN NID registration that has been entered
 into the IANA registry of URN NIDs.  IANA has registered the NID

7. SMPTE Registration Authority (Informative)

 The URL of the SMPTE Registration Authority is

8. References

8.1. Normative References

 [RFC2141]   Moats, R., "URN Syntax", RFC 2141, May 1997.
 [RFC3406]   Daigle, L., van Gulik, D., Iannella, R., and P.
             Faltstrom, "Uniform Resource Names (URN) Namespace
             Definition Mechanisms", BCP 66, RFC 3406, October 2002.
 [SMPTE2029] Society of Motion Picture and Television Engineers,
             "Uniform Resource Names for SMPTE Resources", SMPTE
             2029-2007, <>.

8.2. Informative References

 [ISO8824-1] International Organization for Standardization,
             "Information Processing - Open System Interconnection -
             Specification of Abstract Syntax Notation One (ASN.1)",
             ISO Standard 8824-1:1995, 1995.
 [RFC3061]   Mealling, M., "A URN Namespace of Object Identifiers",
             RFC 3061, February 2001.
 [RFC4234]   Crocker, D., Ed., and P. Overell, "Augmented BNF for
             Syntax Specifications: ABNF", RFC 4234, October 2005.

Edwards Informational [Page 7] RFC 5119 SMPTE URN Definition February 2008

 [RP210]     Society of Motion Picture and Television Engineers,
             "Metadata Dictionary Registry of Metadata Element
             Descriptions", SMPTE RP210, <>.
 [RP224]     Society of Motion Picture and Television Engineers,
             "Registry of SMPTE Universal Labels", SMPTE RP224,
 [SMPTE298M] Society of Motion Picture and Television Engineers,
             "Universal Labels for Unique Identification of Digital
             Data", ANSI / SMPTE 298M-1997, <>.
 [SMPTE336M] Society of Motion Picture and Television Engineers, "Data
             Encoding Protocol using Key-Length-Value", SMPTE 336M-
             2001, <>.

Author's Address

 Thomas G. Edwards
 10201 West Pico Boulevard
 Los Angeles, CA  90035
 Phone: +1 310 369 7093

Edwards Informational [Page 8] RFC 5119 SMPTE URN Definition February 2008

Full Copyright Statement

 Copyright (C) The IETF Trust (2008).
 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

Intellectual Property

 The IETF takes no position regarding the validity or scope of any
 Intellectual Property Rights or other rights that might be claimed to
 pertain to the implementation or use of the technology described in
 this document or the extent to which any license under such rights
 might or might not be available; nor does it represent that it has
 made any independent effort to identify any such rights.  Information
 on the procedures with respect to rights in RFC documents can be
 found in BCP 78 and BCP 79.
 Copies of IPR disclosures made to the IETF Secretariat and any
 assurances of licenses to be made available, or the result of an
 attempt made to obtain a general license or permission for the use of
 such proprietary rights by implementers or users of this
 specification can be obtained from the IETF on-line IPR repository at
 The IETF invites any interested party to bring to its attention any
 copyrights, patents or patent applications, or other proprietary
 rights that may cover technology that may be required to implement
 this standard.  Please address the information to the IETF at

Edwards Informational [Page 9]

/data/webs/external/dokuwiki/data/pages/rfc/rfc5119.txt · Last modified: 2008/02/12 18:58 by

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki