US Patent 7389046 Simplified switching interconnect using wavelength division multiplexing

A network of spine switches and leaf switches is disclosed wherein the spine switches and leaf switches are coupled using a simplified interconnect made up of multiple signal carrying media (SCM's). In the simplified interconnect, “virtual” links are used rather than physical links to couple the leaf switches to the spine switches. The virtual links are implemented using wavelength division multiplexing. By implementing virtual links, the network achieves the same connectivity as that provided by a Clos network without the complex interconnect that is typically required in a Clos network.