Shortest Path Bridging (SPB) is a bridging technique specified by the IEEE802.1aq working group. The SPB standard specifies shortest bridging of unicast and multicast frames, including calculation of multiple spanning trees and localization of stations.
Shortest Path Bridging uses the Link State Protocol ( LSP) to calculate the Shortest Path Tree (SPT) for each node. The LSP protocol is used to discover and display the shortest link structures of all bridges in the SPB area. Depending on the SPB concept, the MAC addresses of the participating stations and the information about the service affiliations of the interfaces are distributed to non-participating stations. This SPB procedure is called Shortest Path Bridging MAC (SPBM). The topology data is used by the computation computer to determine the least cost links from each node to all other participating nodes. Another SPB technology is TRILL (Transparent Interconnection of Lots of Links).