Lightnets: topologies for high-speed optical networks

An inherent problem of conventional point to point wide-area-network (WAN) architectures is that they cannot translate optical transmission bandwidth into comparable user-available throughput due to the limiting electronic processing speed of the switching nodes. A solution to wavelength-division-multiplexing (WDM) -based WAN networks that addresses this limitation, called the Lightnet architecture, is proposed. It trades the ample bandwidth obtained by using multiple wavelengths for a reduction in the number of processing stages and a simplification of each switching stage, leading to substantially increased throughputs. The principle of the Lightnet architecture is the construction and use of a virtual topology network in the wavelength domain, embedded in the original network. The embedding of virtual networks with regular topologies is studied. Algorithms for the embedding of alternative regular topologies are presented, and their performance is evaluated. It is shown that compared to conventional network architectures, Lightnets offer substantial performance gains in terms of increased throughput and smaller buffering requirements