Fabric Topologies; Cascaded Fabric - HP StorageWorks 64 - SAN Director Switch Planning Manual

Fabric Topologies

Several topologies exist from which to build a Fibre Channel fabric infrastructure.
This section describes the most effective fabric topologies, and provides guidance
on when to deploy each topology. The topologies are effective for a wide variety
of applications, are extensively tested by HP, and are deployed in several customer
environments.
Fabric topologies described in this section include:
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Cascaded Fabric

A cascaded fabric consists of a linear string of directors or switches connected by
one or more ISLs. Each fabric element is connected to the next fabric element in
line. The end-point fabric elements are not connected to each other.
illustrates a cascaded fabric topology.
Cascaded fabrics are typically inexpensive, easy to deploy, and provide a simple
solution to add additional fabric devices. However, this fabric design has low
reliability because each director, switch, or ISL is a single point of failure. In
addition, the design has limited scalability because the maximum hop count can
be quickly exceeded when fabric elements are added.
SAN High Availability Planning Guide
Cascaded.
Ring.
Mesh.
Core-to-edge.
Fabric islands.
Planning Considerations for Fibre Channel Topologies
Figure 36
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