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

As you add switches, ISLs are connected to two or more adjacent switches to maintain mesh
connectivity, ensuring path redundancy throughout the fabric (Figure 4). The additional ISL
connectivity provides communicating devices with more paths through the fabric. This dramatically
reduces the chance that, as you add switches, you will exceed the maximum hop count.
Figure 4 ISL connections in a meshed fabric
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Switch models
All HP Fibre Channel switches are supported for use in a meshed fabric topology. Meshed 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. To meet higher port-count requirements, use Core or Director switches.
Benefits
The benefits of a meshed fabric include:
• Ability to meet multiple data access needs
• Multiple paths for internal fabric resiliency
• Ease of scalability
• Shared backup and management support
• Support for a mix of local and distributed data access (see “Topology data access” (page 32))
• Less impact on performance due to intraswitch traffic
Ring fabric
A ring fabric is a ring of interconnected switches (Figure 5). The ring fabric provides a similar level
of fabric resiliency as the meshed fabric and ensures full fabric connectivity with a minimum of two
paths for each switch.
The ring fabric enables you to:
• Scale the fabric in a modular fashion.
• Achieve optimum I/O performance by connecting a group of servers and storage to one
switch.
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