Q-Logic 16HA user manual Cascade Topology

Cascade Topology

Cascade Topology

The term “cascade” indicates that chassis are connected in a line “one-to-the- next”. You may optionally have chassis interconnections from the last chassis back to the first chassis (Loop). The loop provides better latency because any chassis can route traffic in the shortest direction to any another chassis in the loop. The loop also provides failover when only one chassis interconnection is used. Figure 5-1shows an example of Cascade-with-a-loop interconnection.

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Figure 5-1 Cascade Example

In fabrics containing two or three chassis, Cascade-with-a-loop topology and Mesh topology are exactly the same. Note in Figure 5-1that if the fabric contained only three chassis and the loop back to the first chassis came from chassis 3, that each chassis would be directly connected to each other chassis which is the definition of Mesh topology.

SANbox-16HA Fibre Channel Switch

Installer’s/User’s Manual 59005-03 Rev. A Multi-Chassis Fabrics 5-5