HP Mainframe Connectivity Design Guide

To add directors to an existing fabric, ensure that the new configuration complies with the current
fabric rules. For more information about fabric rules, see:
“B-series FICON directors and fabric rules” (page 29)
“C-series FICON directors and fabric rules” (page 46)
“McDATA FICON directors and fabric rules” (page 63)
158 FICON SAN best practices