X.500

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X.500

(standard, networking)
The set of ITU-T standards covering electronic directory services such as white pages, Knowbot, whois.

Compare: LDAP.

X.500

An OSI protocol for managing online directories of users and resources. X.500 can be used to support X.400 and other messaging systems, but it is not restricted to email usage. It provides a hierarchical structure that fits the world's classification system: countries, states, cities, streets, houses, families, etc. The goal is a global directory.

The DIB, DSA and DCA
An X.500 directory is called a "Directory Information Base" (DIB) or white pages. The program that maintains the DIBs is called a "Directory Server Agent" (DSA). A Directory Client Agent (DCA) is used to search DSA sites for names and addresses.

Replication and Access Control
Published in 1988, the 1993 edition of X.500 added replication and access control. Using the Directory Information Shadowing Protocol (DISP), replication allows a portion of the Directory Information Tree (DIT) to be copied between nodes. Access control allows or denies access to a particular attribute of a directory entry based on the identity of the requesting user. See X.400.
References in periodicals archive ?
population (original magnifications X100 [A] and X500 [C]; original magnification X100 [B and D]).
X500 (From Wednesday) Drama, starring Jembie Almazan.
Sciex's Routine Biotransform Solution is comprised of the ExionLC AD system, X500 QTOF System (Quadruple Time of Flight) platform and MetabolitePilot Software 2.
En ese mismo grupo participa el filme X500 (Canada, Colombia y Mexico), de Juan Andres Arango.
Fiat had raised the price of Tipo by EGP 25,000 recording EGP 199,900; Doblo and 500 by EGP 10,000 to reach EGP 164,900 and EGP 244,900, respectively; Qubo and X500 by EGP 20,000 recording EGP 154,900 and EGP 284,900, respectively; and the 500c by EGP 15,000.
After finishing and polishing, samples were scanned as a whole with the help of SEM and photomicrograph of areas of interest taken at XI20 and X500 magnification.
The company has some great special offers lined up for you on the day, for instance, when you purchase a lawn tractor from the famous X100, X300 and X500 range, you'll get an extra 10% discount plus a FREE Lawn Tractor Utility Trailer, or Stihl Electric Pressure Washer.
Getac, a manufacturer of rugged mobile technology, released its X500 rugged mobile server, designed to provide highly portable, secure data storage in the field when access to a secure network is not possible.
The X500 offers diverse interfaces, machine body function-proof design, and high-power wireless transmission capability, befitting military requirements and saving cost on unnecessary customization.
Getac UK, a subsidiary of Getac Technology Corporation, said today that it has developed a new COTS (commercial off the shelf) rugged military command laptop computer, the X500, with a 15.
Toshiba Computer Systems has launched updated models of its consumer laptops Satellite A660, Satellite A665, Satellite A665 3D and Qosmio X500.