Directory Access Protocol

Directory Access Protocol (DAP) is a computer networking standard promulgated by ITU-T and ISO in 1988 for accessing an X.500 directory service. DAP was intended to be used by client computer systems, but was not popular as there were few implementations of the full OSI protocol stack for desktop computers available to be run on the hardware and operating systems typical of that time. The basic operations of DAP: Bind, Read, List, Search, Compare, Modify, Add, Delete and ModifyRDN, were adapted for the Novell Directory Services (NDS) and the TCP/IP-based Lightweight Directory Access Protocol (LDAP).^[1]

DAP is specified in X.511.^[2]

^ J. Sermersheim (June 2006). Lightweight Directory Access Protocol (LDAP): The Protocol. Network Working Group. doi:10.17487/RFC4511. RFC 4511. Proposed Standard. Obsoletes RFC 3771, 2830 and 2251. The core protocol operations defined in this document can be mapped to a subset of the X.500 (1993) Directory Abstract Service [X.511]. However, there is not a one-to-one mapping between LDAP operations and X.500 Directory Access Protocol (DAP) operations.
^ X.511 : Information technology – Open Systems Interconnection – The Directory: Abstract service definition

[1] J. Sermersheim (June 2006). Lightweight Directory Access Protocol (LDAP): The Protocol. Network Working Group. doi:10.17487/RFC4511. RFC 4511. Proposed Standard. Obsoletes RFC 3771, 2830 and 2251. The core protocol operations defined in this document can be mapped to a subset of the X.500 (1993) Directory Abstract Service [X.511]. However, there is not a one-to-one mapping between LDAP operations and X.500 Directory Access Protocol (DAP) operations.

[2] X.511 : Information technology – Open Systems Interconnection – The Directory: Abstract service definition

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