The CiscoSecure ACS has three components:
AAA clientsMakes requests and communicates with the AAA server, sending usernames and other parameters.
AAA serverReceives authentication requests from the clients, compares them to a database, authorizes the client, and begins accounting tasks.
User or accounts databaseCan be Open Database Connectivity (ODBC), Lightweight Directory Access Protocol (LDAP), Novell Directory Services (NDS), or Windows NT, 2000, or 2003. It allows an administrator to easily manage users and groups with different levels of permissions.