Fibre Channel Addressing and Routing Routing and FSPF
FSPF
• Fabric Shortest Path First (FSPF):
– Creates a set of paths which are used for routing
– Computes the least-cost path between the nodes based on number of hops
– Avoids looping of frames
Frame 1 Frame 2 Frame 3
– All frames follow the same path, ensuring in-order delivery
The Fabric Shortest Path First (FSPF) protocol was developed to address routing path issues in Fibre Channel fabrics: • A function called the Path Selector creates a set of paths through the fabric. These paths are used by the Routing Function to route frames in the most efficient manner.
• The FSPF algorithm is a cost-based routing algorithm. It computes the shortest path between two connected nodes by assigning a cost to each path. Every path has a cost equal to the number of hops between switches
• This algorithm avoids looping of frames. In addition, all frames in an exchange follow the same path, ensuring in-order delivery.
FSPF is similar in many ways to the Open Shortest Path First (OSPF) protocol used today on most IP networks.