.Part 1 Architecture HP SAN Design Reference Guide 785351-001

Switch models
All HP Fibre Channel switches are supported for use in a cascaded fabric topology. Cascaded
fabric topologies typically use the SN6000 Fibre Channel Switch; the 8/20q Fibre Channel Switch
(or the HP Simple SAN Connectivity Kit); or SAN, Fabric, or Edge switches, which support smaller
incremental growth.
NOTE: Over time, a cascaded fabric topology can result in increased hops between switches.
B-series, C-series, and H-series fabrics must not exceed seven hops. For additional switch hop
information, see:
• “B-series switches and fabric rules” (page 91)
• “C-series switches and fabric rules” (page 123)
• “H-series switches and fabric rules” (page 140)
Benefits
The benefits of a cascaded fabric include:
• Ability to connect SANs in diverse geographic locations
• Ease of scalability for increased server and storage connectivity
• Shared backup and management support
• Optimum local performance when communicating devices are connected to the same switch
in the cascaded fabric
• Cost efficiency due to the large number of switch ports available
• Support for local data access and occasional centralized data access
Meshed fabric
A meshed fabric is a group of interconnected switches using multiple ISLs for fabric resiliency
(Figure 3). If one ISL fails, the switch automatically reroutes data through an alternate path in the
fabric. If the alternate path includes other switches, the data must pass through those switches to
reach its destination.
Figure 3 Meshed fabric
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26 SAN fabric topologies