在架构於多波长分工网路上的网际网路通讯协定中整合极....ppt

Outline Introduction Background Motivation Problem Description Proposed Approach Problem Formulation and Solution Approach Lagrangian Relaxation Getting Primal Feasible Solutions Computational Experiments Summary and Future Work Background Recently IP traffic has increased explosively due to web browsing and emerging multimedia services. Wavelength division multiplexing (WDM) has been considered as a promising transmission technology in optical communication networks. Background (cont’d) WDM can be viewed as a parallel set of optical channels, each using a slightly different light wavelength, but all being multiplexing on the same fiber. Background (cont’d) WDM sub-systems (e.g. Optical Cross-Connect, OXC) provide wavelength switching functions. Background (cont’d) In a WDM network employing OXCs, a lightpath can be established using a wavelength, which means that the WDM network provides wavelength routing capability. Background (cont’d) The routing capacity provided by a WDM network allows for overlaying “virtual” higher-layer protocol topologies on the top of the physical layer topology (WDM network), where the lightpaths represent virtual links. Researchers now are trying to find a way to support IP traffic on the WDM network directly, without intervening intermediate layers. This concept is known as IP over WDM. Background (cont’d) Motivation For efficient utilization of IP over WDM networks in the near future, we propose a mathematical formulation and an optimization-based algorithm designing IP topology and routing assignment over WDM networks. Problem Description Assumptions: The OSPF link cost metrics in IP routers are reconfigurable. The OXCs are reconfigurable through UNI interface defined. Given: The set of IP routers The set of OXCs The set of WDM links Traffic demand of each IP OD pair The capacity of each wavelength The number of wavelength in each WDM link The number of add/drop port for each wavelength in the OXC corresponding to each router The co