The base configuration for Cisco MDS 9100 Multilayer Fabric Switches includes enough active ports for the customer to build an entry-level storage area network (SAN). On-demand ports allow the customer to benefit from Cisco MDS 9000 SAN-OS Software features, while initially purchasing only a small number of activated ports on a Cisco MDS 9100 switch. Customers can expand switch connectivity as needed by licensing additional ports.