Sun Java System Portal Server 7 Deployment Planning Guide

Application Server Requirements

One of the primary uses of Portal Server installed on an application server is to integrate portal providers with Enterprise JavaBeansTM architecture and other J2EETM technology stack constructs, such as Java Database Connectivity (JDBCTM) and J2EETM Connector Architecture (JCA), running on the application server. These other applications and modules can consume resources and affect your portal sizing.