Preliminar
y
Mesh Topology
SANbox-16HA Fibre Channel Switch
Installer’s/User’s Manual
59005-03 Rev. A
Multi-Chassis Fabrics
5-9
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-16 chassis connected in Mesh topology expand from two chassis to a
maximum of nine chassis. With each chassis using eight T_Ports for chassis inter-
connection, then each chassis will have 8 user ports remaining.
Figure 5-2
shows
an example of mesh interconnections.
Using four to eight chassis, Cascade-with-a-loop topology can result in more user
ports than Mesh topology.
Using six 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 only 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.
