Q-Logic SB2A-16B Manuel D’Utilisation
3 – Planning
Multiple Chassis Fabrics
Multiple Chassis Fabrics
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3.4.3
Common Topologies
The SANbox2-16 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
series. If you connect the last switch back to the first switch, you create a
cascade-with-a-loop topology as shown in
. 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.
loop. The loop also provides failover should a switch fail.
The cascade fabric shown in
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.
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.
48 Fibre Channel ports are available for devices.
Figure 3-1. Cascade-with-a-Loop Topology