When planning your SAN, you might require more than one switch to accommodate all of the entities. The following topologies are used to interconnect fabric switches:
A cascade topology interconnects two switches, using two or more cables connected to ports on each switch. More than one interconnecting cable is used to increase the bandwidth of data transferred and to provide redundancy in case any one connection goes down.
Cascade loop topology is used for three or more switches, where the first and last switch are further interconnected. This allows data to follow the "first or shortest path first" (FSPF) rule, a standard function of fabric protocol.
Mesh topology has each switch fully interconnected to every other switch. This allows for greatest efficiency and redundancy in the fabric.