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INTERNET-DRAFT C. Apple <draft-apple-schema-listing-rqmts-00.txt> AT&T Laboratories Expires: January 26, 1998 26 July 1997
Directory Schema Listing Requirements <draft-apple-schema-listing-rqmts-00.txt>
Status of this Memo
This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts.
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Abstract
This memo documents requirements for listing directory services schemas in a centrally operated, administered, and maintained repository. This repository will be available as a resource to directory protocol and service implementors to facilitate schema discovery.
1.0 Introduction
The fastest route to interoperable directory services is through standard object classes and attribute types. There is a growing number of places where schema for Internet Directory Services and Internet Operations are being defined, with varying degrees of documentation. This plethora of schemas is unavoidable in the light of the needs of different service communities, but it makes it difficult for directory service builders to find and make use of an existing schema that will serve their needs and increase interoperability with other systems. A listing service providing a single point of discovery for white-pages schema will promote schema
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reuse, reduce duplication of effort, and thus promote directory service interoperability.
This document contains requirements for various aspects of listing schemas.
2.0 Listing Service Requirements
2.1 Functional Requirements
Schema are 'listed' rather than 'registered'.
A list of available schemas MUST be maintained.
Schema will be named according to the namespace defined in section 3.
The listing service shall also maintain information about the schema, beyond its definition. This information is referred to as meta data and will include information about the following differentiating characteristics:
+ a globally unique identifier for the schema name + protocol and protocol version for which the schema is valid + name/title of schema + version information for the schema + date of creation or update + indication of listing status + indication of relationship to other schemas + originating organization or individual + name of contact person for schema + e-mail of contact person for schema + telephone of contact person for schema + postal address of contact person for schema
2.2 Operational Requirements
The process of listing schema will be centralized for the initial deployment.
The database which provides the listing store will be centrally administered.
Listing files will be accessible via FTP and HTTP.
Listing content and listing meta data will be stored in a file named in accordance with the file name syntax defined in section 5.0.
Listing content and listing meta data will be stored in a file
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formatted in accordance with section 5.0.
3.0 Listing Service Namespace
The listing service namespace shall be protocol-independent.
Names constructed using the listing service namespace shall be permanent, globally unique, and publicly available.
3.2 Listed Schema Name Syntax
<schema_name> ::= <protocol_type> '-' <opaque_string>
<protocol_type> ::= <protocol_ID> ['v' <protocol_version>]
<protocol_ID> ::= IANA-assigned directory service protocol identifier
<protocol_version> ::= a protocol version number string
<opaque_string> ::= protocol-specific information
Consider the following example of a schema name for the vCard schema [VCARD] for use in LDAPv3 [LDAPV3]:
ldapv3-vCardObject
where: vCardObject is the name of the object class identified by the OID: 1.3.6.1.4.1.2309.1.1.1.1 [VCARD]
An alternate, but still globally unique, name for this schema is:
ldapv3-1.3.6.1.4.1.2309.1.1.1.1
4.0 Listing Requirements
Schema listing content will be composed only of the information actually required to specify the schema.
Schema listing meta data will be composed of other information as defined in paragraph 4.2.
4.1 Listing Content
4.1.1 Allowable Listing Content Syntaxes
LDAP Data Interchange Format [LDIF]
Abstract Syntax Notation One [ASN1]
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BNF [RFC822]
Augmented BNF [ABNF]
TBR. Working group needs to achieve consensus on the list of allowable syntaxes.
4.1.2 Allowable Listing Content Character Sets
As specified in references for allowable listing content syntaxes.
Exceptions: TDB. Working group needs to achieve consensus on whether or not profiling of these syntaxes is necessary/appropriate.
4.2 Listing Meta Data
4.2.1 Listing Meta Data Syntax
TBD. Working group needs to achieve consensus on which meta data elements are important enough to include (see paragraph 2.1).
4.2.2 Allowable Listing Meta Data Character Sets
TBD. Working group needs to achieve consensus on allowable character sets.
5.0 Listing Storage Requirements
Listing file names shall be permanent and publicly available. 5.1 Listing File Name Syntax
The content and meta data for each listing shall be contained in a file named according to the following syntax:
<file_name> ::= "ietf-schema-directory-" <sequence_number> ".txt"
<sequence_number> ::= <d><d><d><d>
<d> ::= '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9'
5.2 Listing File Format Specification
TBD. Dependent on resolution of TBDs for section 4.0.
6.0 Security Considerations
Security requirements are not discussed in this memo.
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7.0 Acknowledgements
Leslie Daigle of Bunyip Information Systems and Chris Weider of Microsoft provided valuable comments on the pre-Internet-Draft- version of this document.
8.0 References
[ABNF] D. Crocker, P. Overell, "Augmented BNF for Syntax Specifications", INTERNET-DRAFT <draft-ietf-drums-abnf-03.txt>, July 1997.
[ASN1] ITU-T Recommendation X.680, "Abstract Syntax Notation One (ASN.1) - Specification of Basic Notation", 1994.
[LDAPV3] M. Wahl, T. Howes, S. Kille, "Lightweight Directory Access Protocol (Version 3)", INTERNET-DRAFT <draft-ietf-asid-ldapv3- protocol-06.txt>, July 1997.
[LDIF] G. Good, "The LDAP Data Interchange Format (LDIF) _ Technical Specification", INTERNET-DRAFT <draft-ietf-asid-ldif-02.txt>, July 1997.
[RFC822] D. Crocker, "Standard of the Format of ARPA-Internet Text Messages", STD 11, RFC 822, August 1982.
[VCARD] F. Dawson, M. O'Brien, "The vCard Schema For Use In LDAPv3", INTERNET-DRAFT <draft-ietf-asid-ldapv3schema-vcard-00.txt>, July 1997.
9.0 Author's Address
Chris Apple AT&T Laboratories 600 - 700 Mountain Ave., Room 2F-165 Murray Hill, NJ 07974-0636 USA
E-Mail: capple@att.com Phone: +1 908 582 2409 FAX: +1 908 582 6113
This INTERNET-DRAFT expires on January 26, 1998.
Apple [Page 5]