Figure 21–2 shows the interaction of the software components in the authentication process of a basic architecture of Instant Messaging. The focus is on the flow of authentication requests. An explanation of the steps in this process follows the figure.
The authentication process in a basic architecture works as follows:
Java Web Start or the Java plugin downloads the necessary Instant Messenger resource files and starts Instant Messenger.
The login window appears and the end user enters the login name and password. The login data is sent to the Instant Messaging server through the multiplexor.
The Instant Messaging server communicates with the LDAP server to authenticate the end user and to request end-user information, such as contact lists or subscriptions.
When the end-user authentication is complete, the Instant Messaging main window appears, displaying the contact list for the end user. The end user can now start and participate in Instant Messaging sessions with the other end users.