X.500

related topics
{math, number, function}
{system, computer, user}
{work, book, publish}
{company, market, business}
{group, member, jewish}

X.500 is a series of computer networking standards covering electronic directory services. The X.500 series was developed by ITU-T, formerly known as CCITT, and first approved in 1988.[1] The directory services were developed in order to support the requirements of X.400 electronic mail exchange and name lookup. ISO was a partner in developing the standards, incorporating them into the Open Systems Interconnection suite of protocols. ISO/IEC 9594 is the corresponding ISO identification.

Contents

X.500 protocols

The protocols defined by X.500 include

Because these protocols used the OSI networking stack, a number of alternatives to DAP were developed to allow Internet clients to access to the X.500 Directory using the TCP/IP networking stack. The most well-known alternative to DAP is Lightweight Directory Access Protocol (LDAP). While DAP and the other X.500 protocols can now use the TCP/IP networking stack, LDAP remains a popular directory access protocol.

X.500 data models

The primary concept of X.500 is that there is a single Directory Information Tree (DIT), a hierarchical organization of entries which is distributed across one or more servers, called Directory System Agents (DSA). An entry consists of a set of attributes, each attribute with one or more values. Each entry has a unique Distinguished Name, formed by combining its Relative Distinguished Name (RDN), one or more attributes of the entry itself, and the RDNs of each of the superior entries up to the root of the DIT. As LDAP implements a very similar data model to that of X.500, there is further description of the data model in the article on LDAP.

X.520 and X.521 together provide a definition of a set of attributes and object classes to be used for representing people and organizations as entries in the DIT. They are one of the most widely deployed white pages schema.

Full article ▸

related documents
Document Object Model
Randomizer
Information hiding
Thread safety
Command-line interpreter
Cepstrum
E.164
Computer algebra system
BASIC09
Linker
RenderMan Interface Specification
International Data Encryption Algorithm
Great Internet Mersenne Prime Search
Roxen (web server)
Wikipedia:Free On-line Dictionary of Computing/I - K
Curl (programming language)
CDR coding
True BASIC
Bootstrapping
Bourne shell
Adder-subtracter
Maxima (software)
SNOBOL
Extensible Stylesheet Language
Code coverage
Triple DES
Scilab
Maclisp
Painter's algorithm
Jess programming language