This example illustrates a sysplex of two systems in which all defaults in the COUPLExx parmlib member are taken. Only the required statements and parameters are shown.

IBM® recommends that you use only the defaults when you initially set up a sysplex. You can then examine the XCF activity reports produced by RMF™ to determine whether a significant number of messages are too big to fit the default buffer sizes. Only in this case should you consider defining transport classes to accommodate larger messages. See Example 2 — Creating a transport class for large messages.

In this scenario, PLEXOF2 (Figure 1) consists of two MVS™ systems (SYSA and SYSB) on two processors. In this example, all defaults are used, and no transport classes are defined. Therefore, MVS creates only the default transport class (named DEFAULT) and assigns all groups (which are collectively called UNDESIG) to the DEFAULT class. Also, MVS assigns all signaling paths to the DEFAULT class, which means that all groups share all paths equally.