Connectivity considerations

FICON® system hardware, CPCs, and FICON Directors significantly affect the volume of logical path requests to a control unit as follows:

• Control units can attach to one or more ports on a Director or to additional ports on other Directors. Each Director port can dynamically connect to many other ports to which channels requesting logical paths are attached.
• For CPCs, each logical partition attaching to the same control unit compete for the logical paths of the control unit.
• In a configuration where control units are shared by different CPCs, I/O configuration definitions for individual control units are not coordinated automatically among the IOCDSs of the different CPCs. Each CPC competes for the logical paths of a control unit.
• Shared channels require the establishment of a logical path for each channel image corresponding to an active LP sharing the channel. This requirement can significantly increase the number of logical paths that a single channel requests.