Introductory Resources for Lightweight Directory Access Protocol (LDAP) Directories

What is LDAP?

LDAP, or Lightweight Directory Access Protocol, is an open-standard protocol for using data in  X.500 directory services and runs over Internet transport protocols, such as TCP, and includes standards for defining models in a directory.

In contrast to RDBMS (Relational Database Management System), two key disinctions of LDAP are that 1) it is optimized for reads, and 2) it is hierarchical, rather than relational. The hierarchical nature of LDAP is fundamentally different from the familiar tabular structures of RDBMS. For more information on LDAP directories and relational databases, refer to Isode's whitepaper "Combining Directories and Relational Databases in the Enterprise."

What is a directory?

A directory is a database optimized for fast look-ups and holds information associated with entries in a hierarchical, rather than relational, model.  It can function similar to a phone book, where an application looks up a name, and then retrieves location information for display or use. Directories can hold information about people, services, or objects, such as printers and other network devices.

What is an enterprise directory service?

In this Roadmap, an enterprise directory service includes more than just the physical directory. The service covers the process of: 

• data extraction from source systems (such as Human Resources and Student Systems),
• identity reconciliation and business logic application to the data (sometimes referred to as the metadirectory), and
• physical directory design and deployment.
See a graphical representation of an enterprise directory for a description of how applications and service platforms work in relation to your core business systems, metadirectories, and physical directories.

LDAP Directory Background Resources 

For more general information about LDAP and directories, refer to the following resources:

Howes, Timothy, Mark Smith, and Gordon Good. Understanding and Deploying LDAP Directory Services. Addison-Wesley Professional, 2003.

An Internet Approach to Directories (Netscape Development) (Michael Donnelly)

Fedora Directory Server Project