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

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