User`s manual

Preliminary
Mesh Topology
SANbox-8 Fibre Channel Switch
Installer’s/User’s Manual 59008-03 Rev. A Multi-Chassis Fabrics 5-15
Mesh Topology
The term “mesh” indicates that each chassis has at least one T_Port directly
connected to each other chassis.
In fabrics containing two or three chassis, Cascade-with-a-loop topology and Mesh
topology are exactly the same. Note in Figure 5-2 that you could take any three
chassis and their interconnections and draw them in a row with a loop back from
the last chassis to the first chassis (the same as Cascade-with-a-loop).
Figure 5-2 Mesh Example
Mesh Fabric Size
SANbox-8 chassis connected in Mesh topology expand from two chassis to a
maximum of five chassis.With each chassis using four T_Ports for chassis inter-
connection, then each chassis will have 4 user ports remaining. Figure 5-2 shows
an example of mesh interconnections.
Using four or five chassis, Cascade-with-a-loop topology can result in more user
ports than Mesh topology.
Using four or more chassis, Multistage topology can result in more user ports than
Mesh topology. Multistage topology is described later in this manual.
Mesh Latency
Each Chassis will route traffic through the path of the least number of chassis hops
to the destination chassis. A chassis will route traffic through other paths if all links
in the closest direction fail.
Latency to any port on the same chassis is one chassis hop. Latency to any port on
any other chassis is two chassis hops (counting the source chassis). This is the
same latency as two or three chassis connected in Cascade -with-a-loop. It is better
than Multistage. Multistage has three hops to any IO/T chassis.