User's Manual

3 – Planning
Multiple Chassis Fabrics
3-8 59042-06 A
0
3.4.3
Common Topologies
The SANbox2-8c switch supports three commonly used fabric topologies:
 Cascade
 Mesh
 Multistage®
3.4.3.1
Cascade Topology
A cascade topology describes a fabric in which the switches are connected in
series. If you connect the last switch back to the first switch, you create a
cascade-with-a-loop topology as shown in Figure 3-1. The loop reduces latency
because any switch can route traffic in the shortest direction to any switch in the
loop. The loop also provides failover should a switch fail.
The cascade fabric shown in Figure 3-1 has the following characteristics:
 Each chassis link contributes up to 200 MB/s of bandwidth between chassis,
400 MB/s in full duplex. However, because of the sequential structure, that
bandwidth will be shared by traffic between devices on other chassis.
 Latency between any two ports is no more than two chassis hops.
 24 Fibre Channel ports are available for devices.
Figure 3-1. Cascade-with-a-Loop Topology