1. Introduction to Directory Services CNS 4650 Fall 2004 Rev. 2

2. What is a Directory Organized information Structure for finding information quickly and efficiently Single source for information

3. Everyday Directories Phonebook Address book Mall/Store Directory File System

4. Example: Phonebook Entries/Objects - Names Attributes - Addresses, Phone number Object Class - City location, type of business

5. Example: File System Entries/Objects - File/Directory names Attributes - Ownership, permissions Object Class - Type of file (directory, character, plain) lr-xr-xr-x 1 root wheel 4 Aug 24 12:16 stdout -> fd/1 crw-rw-rw- 1 root wheel 20 Sep 2 21:13 tty drwxr-xr-x 4 root wheel 136 Jan 15 2003 resolver -rw-r--r-- 1 root wheel 0 Jan 15 2003 rmtab

6. X.500 ITU & ISO Actually a set of standards Ratified in 1988, 1993, 1997 Built on OSI model Also known as DAP (Directory Access Protocol)

7. LDAP Univ. of Michigan ~1995 (version 2) IETF Lightweight DAP TCP/IP based Simple API

8. Other Directories Novell NDS (Netware 4 <) NT Networking NIS (UNIX/SUN) DNS Flat-files

9. Directory: Piece by Piece Schema Object/Entry Directory Information Tree Directory Information Base Partitions

10. Schema Defines the directory What objects can exist What attributes the objects have How the directory is structured Enforces rules

11. Object/Entry Contain attributes Defined syntax for those attributes Attributes can be optional or mandatory Attributes can be string of text or numbers to binary data (such as a photo or digital certificate)

12. Object Classes Think of these as “stereotypes” Quickly give objects attributes Similar to C++/Java Classes Can be sub-class of other classes Multiple object classes can be assigned to a single object

13. Directory Information Tree Inverted tree Hierarchical layout of the directory Certain objects can be “Container” object Visual display of the directory

14. Directory Information Base Where the directory is stored Usually optimized for searching and retrieving of data Usually indexed

15. Partitions Subdivide large data stores Use replication for data synchronization Also for redundancy and fault tolerance

16. Why the Study of Directories? Chances are you use at least one everyday The future is based in directories This is largely misunderstood by majority of the population

17. Sources Sheresh & ShereshSheresh R. & Sheresh B. (2002) Understanding Directory Services Indianapolis: SAMS