User`s manual

Table Of Contents
Preliminary
Cascade Topology
SANbox-16STD Fibre Channel Switch
Installer’s/User’s Manual 59012-03 Rev. A Multi-Chassis Fabrics 5-7
Also, traffic destined for any port NOT on the same chassis as the source port will
be sharing the interconnection bandwidth with any other ports on other chassis that
need to communicate over those same chassis links.
In fabrics of two or three chassis, Mesh and Cascade-with-a loop topologies are the
same for purposes of bandwidth. For fabrics of four or more chassis, Mesh
topology must use only one T_Port connected to each other chassis in the fabric
because if you used two or more from each chassis you would use up too many
ports to interconnect the chassis. Thus, cascaded connections may result in better
bandwidth than Mesh.
Multistage topology has the best bandwidth. All T_Ports from each IO/T chassis
connect (through the CC chassis) to all other IO/T chassis in the same number of
chassis hops (three) no matter how large the fabric is. Thus the useful interconnec-
tion bandwidth from each IO/T chassis increases by 100MBs per T_Port. It is
possible in Multistage topology to devote half of the chassis bandwidth to T_Ports
thus providing as much as 800 MBytes per second bandwidth between any two
IO/T chassis.
Cascade Physical Distance between Chassis
Cascade topology can cover the largest campus area relative to other topologies. A
cascaded topology can be laid out in a loop with the distance between adjacent
chassis equal to or less than the maximum cable length of the installed GBICs.
Cascade Zoning
Sanbox Switch chassis support fabric-wide zones for all zone types. Broadcast
Zones and Name Server Zones require no special consideration in a cascade fabric.
That is, you may assign these zones on a user-port-by-user-port basis and T_Ports
are not zoned.
Hard Zones, however, require zoned T_Port interconnections between chassis
which contain ports in the same Hard Zone. That is, if a particular Hard Zone is
distributed across chassis boundaries, each piece of that Hard Zone and its inter-
connecting T_Ports must be assigned to the same Hard Zone number. This makes
interconnections between pieces of the same Hard Zone much like the interconnec-
tion of chassis.
NOTE:
Also, remember that mixing of topologies is not allowed. If the fabric topology
is Cascade, then the interconnection of the Hard Zones must also be accom-
plished in Cascade topology.