LDAP Directory Technology Review

Directory Servers are generally used in enterprise-scale systems primarily for authenticating users. The decision to use a Directory Server as opposed to a Relational Database was based on a number of factors outlined in this chapter which were determined from existing literature and related Internet resources.

Many applications and services can take advantage of data that is centralised in a directory (Brian Arkills, 2002), something which is key to the success of the proposed system as the interoperability between the technologies used (Apache, PHP, Bind, etc.) for the deliverables of this project.

Most modern browsers support the LDAP protocol and are completely functional clients for retrieving information from LDAP (Brian Arkills, 2002). The compatibility of modern browsers with the LDAP protocol makes it the ideal solution for the proposed system, as all the core system information will be kept within OpenLDAP and accessed by the users according to the inherited privileges they have after authenticating into the system.

In addition, PHP, the scripting language used to develop the management application, has built-in support for interaction with Directory Servers through the LDAP protocol, providing support for the most regularly used functionality (E.g.: Add new records, Modify records, etc.)

According to literature available on the Zytrax Inc. website, the LDAP protocol was designed to replace the DAP (Directory Access Protocol) which was too complicated as it provided network connectivity to the X.500 Directory Server implementation using all OSI Layers and applications needed to incorporate additional and complex functionality in order to interact with a Directory Server.

LDAP, as its name implies, is a Lightweight version of the DAP, which instead of using all the layers – as defined in the OSI specification – connects to Directory Servers through the TCP/IP protocol only, thus simplifying the development process.

Several Directory Server implementations are available through commercial and open-source vendors. Microsoft® has released the Active Directory™, Sun Microsystems® has released the Sun Java System Directory Server™, IBM® has released the SecureWay™, Oracle® has released the Internet Directory™ and more implementations are being made available from various commercial software vendors.

The adoption of Directory technology by the major vendors by itself indicates its significance, even though it can not be considered to be mature enough to be considered as an alternative to the Relational Model. Several vendors have released Directory implementations with features found in RDBMSs, such as support for transactions.