Fibre Channel SAN Topologies
Arbitrated Loop
Switched Hubs
• Switched hubs allow multiple
devices to communicate
simultaneously
• Scaled bandwidth:
– Each pair of devices has
access to the full link
bandwidth
• Still uses FC-AL topology:
– Same limit of 127 addresses
– Same limited management
features as loop hubs
“Switching” Hubs:
Use loop segmentation to allow multiple devices to communicate
simultaneously
Effective bandwidth scales as devices are added to the loop (because
simultaneous conversations are allowed)
Extend the usefulness of lower-cost FC-AL implementations
“Switching” Hubs still use the same FC-AL protocol used by loop hubs:
Addressing limit of 126 node ports plus one FL_Port
Switching hub does not provide “intelligence” or participate in FC-AL
operations