Q-Logic 16HA Manuel D’Utilisation

A chassis in a Mesh topology divides its chassis interconnection bandwidth among 
the other chassis in the fabric. That is, each chassis has at least one T_Port connec-
tion to each other chassis in the fabric. In small fabrics of two or three chassis, you 
could have two or more connections to each other chassis. In fabrics of four or five 
chassis you should connect only one T_Port to each other chassis. Otherwise you 
will use more than half of your ports as T_Ports. 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 another path if all links in the closest path fail.

In fabrics of two or three chassis, Mesh and Cascade-with-a loop may be the same 
for purposes of bandwidth.

Multistage topology has the best bandwidth. All T_Ports from each IO/T chassis 
connect to all other IO/T chassis in the same number of chassis hops (three) no 
matter how large the fabric is. Thus the useful interconnection bandwidth from 
each IO/T chassis increases by 100MBs per T_Port. It is therefore possible, in 
Multistage topology, to provide as much as 800 MBytes per second bandwidth 
between chassis.

Mesh topology can be laid out in an area where the distance between any two 
chassis is equal to or less than the maximum cable length of the installed GBICs.

Both Cascade-with-a-loop and Multistage topologies can produce larger areas.