Description of the illustration recommendmultitierarch.gif

This graphic has on the left the label "Untrusted" bounded by a dotted line. It is connected by a line to a box labeled "Firewall," which is connected to another box labeled "Load Balancer," which points with three arrows to three pentagons.

The three pentagons are in a column labeled "WebLogic Server Cluster ('Web, presentation tier')." Each pentagon contains labels "HTTP,""JSP," and "Servlet." The pentagons point as a group with three arrows to another column of pentagons, labeled "WebLogic Server Cluster (object tier." Those pentagons contain the labels "EJB" and "JDBC. "Each of the pentagons points to a database.