For additional dynamic PU definitions that are possible using the configuration services XID exit, see Defining a PU and an LU for the configuration services XID exit routine in z/OS Communications Server: SNA Resource Definition Samples.

You can code one or more model major nodes, or copy and modify the model major node provided on the sample library (ISTMODEL on SYS1.SAMPLIB). Model major nodes contain the parameters that VTAM® uses to create dynamic switched resources.

Define a model major node with a VBUILD definition statement (TYPE=MODEL). The PU and LU definition statements in the model major node define the characteristics of switched peripheral nodes.

Model PU and LU statements are defined for the minor nodes. When the configuration services XID exit routine returns the names of the model resource and the previously undefined resource, VTAM uses these model statements to create the dynamic PUs and LUs. The exit can also identify the name of a dynamic switched major node. There is no relationship between these PU and LU definition statements in a model major node. The exit routine can provide the name of any model PU or LU definition that matches the device characteristics. Therefore, there is no sifting done from the PU definition to the LU definition. The GROUP definition is available only for sifting down to the LU definitions.