This Recommendation describes a directory services architecture for multimedia conferencing using LDAP. Standardized directory services can support association of persons with endpoints, searchable white pages, and clickable dialling. Directory services can also assist in the configuration of endpoints, and user authentication based on authoritative data sources.  This Recommendation describes a standardized LDAP schema to represent endpoints on the network and associate those endpoints with users. It discusses design and implementation considerations for the inter-relation of video and voice-specific directories, enterprise directories, call servers and endpoints.