A logical network directory database compliant with the X.500 standard for a directory data system is disclosed. The network directory database provides a source of subscriber and service data accessible by various control and management processes that require subscriber information. The network directory database may be extensible across various communications service providers and IT domain. Further, the disclosed network directory database may be applied to new and existing services, such as, IP Multimedia Subsystem, Unlicensed Mobile Access (UMA) and other IP services.