Management of logical topologies for dynamically changing traffic in reliable IP over WDM networks

摘要

A protection method is one of most promising methods for building reliable IP over WDM networks. To construct the IP over WDM network with protection, protection paths as well as primary paths are set up to be embedded within a logical topology. However, many conventional approaches assume that the traffic demand is known a priori. It is possible that against the changing traffic volume/pattern, we apply the design method based on the current traffic characteristics, and reconfigure the logical topology. However, during the reconfiguration process, releasing the wavelength resources allocated for elder lightpaths causes traffic loss. In this paper; we consider a new approach, called an incremental capacity dimensioning approach, which consists of three steps for designing the logical topology: an initial phase, an incremental phase, and readjustment phase. By our approach, the logical topology can be adjusted according to the changed traffic demands. Through numerical examples we show that the algorithm takes a much smaller number of traffic loss operations during reconfiguration of the logical topology.