This graphic shows four pentagons, as in Figure 3-2. The north pentagon is labeled A; the east pentagon is labeled B; the south pentagon is labeled C; the west pentagon is labeled D. Each pentagons contains four boxes labeled "JSP," "EJB," and "JDBC."All of the four boxes in a pentagon are connected by lines. Arrows with arrowheads on both ends, labeled "Potential IP Socket" connect the pentagons as follows:

Two arrows connect pentagon A to pentagon B. The place where the arrows point to pentagon A has a label, "'Pinned' RMI." One arrow connects pentagon B to pentagon C; one arrow connects pentagon C to pentagon D; two arrows connect pentagon D to pentagon A; one arrow connects pentagon A to pentagon C.