SAN Design: March 29, 2001 3:18 pm
53-0001575-01 BROCADE Technical Note Page: 13 of 31
2.8 STAR TOPOLOGY DESIGN
In the traditional data networking world, star topology network has a core of networking equipment (hubs, switches, and routers) with other
equipment radiating out from this. A star topology SAN is fundamentally the same: It contains one or more “core” switches, surrounded by
one or more “edge” switches.
FIGURE 8.
FIGURE 9. Star Topology -- with Core and Edge Switches
There is a difference between a fibre channel star architecture and a traditional data network star. Because the fibre channel routing protocol
FSPF provides superior load sharing characteristics, there could be as many as sixteen core units. If the star were built with future, higher
port count products, the count could be even higher. FSPF will distribute connections across all cores more or less evenly.
2.8.1 SIMPLE VS. COMPLEX CORES
Each core “unit” in a star SAN can be a single switch (simple), or a group of switches (complex). All of the examples given to this
point, there are two cores, each of which is a single switch.
Core
Edge