Research And Simulated Implementation Of Routing Mechanism For Survivability In IP Over WDM Optical Networks

In recent years, the explosive growth of Internet services has brought unprecedented challenges to the transmission network, and promoted the development of telecommunications transmission network toward high bandwidth and multi-service. With the WDM (Wavelength Division Multiplexing, WDM) technology has become more sophisticated, it has become an effective solution to solve high network bandwidth requirements with the ability to provide tremendous bandwidth. In order to reduce network operating costs and improve utilization of bandwidth resources,IP over WDM which is running IP protocol on WDM optical Networks directly has become the development trend of the optical network. Once such high-bandwidth, multi-level network failure, large amounts of data will be losed and would result in incalculable consequences. In addition, the size of the network continues to expand and the coexistence of multiple network operators making the actual backbone optical network is consisted of a number of autonomous domains. Based on this this paper presents the routing mechanism for survivability in IP over WDM optical network.In this thesis,in consideration of the delay constraint and the protection constraint of routing requests and the continuous fault which is casued by man-made attacks or natural disaster in the network, survivability routing mechanism in IP over WDM optical network is proposed. First, the boundary list which is used to guide rounting request for inter-domain routing,Next, design a multi-layer auxiliary graph in each domain to solve the problem of routing and wavelength assignment in IP layer and WDM layer, According to the latency requirements of routing request,working path is computed and wavelength is assigned on the multi-layer auxiliary graph to achieve domain routing and wavelength assignment; Then,when we cannot find a rout to meet the routing request, intra-domain and inter-domain backtracking is performed until find a path from a source node to a destination node meet the requirements of the rout; Finally, man-made attack or natural disasters may cause partial failure of the link, we use Probabilistic Shared Risk Link Group model to get the protect path. According to the protection requirements of routing request to find the inter-domain protect path based on Boundary list, and find the intra-domain protect path and assign wavelength on the multi-layer auxiliary graph.To validate the viability and effectiveness of the proposed mechanism, simulation and performance analysis are implemented. The simulation results show that the mechanism can not only effectively solve the survival problem of routing in IP over WDM network,but also has good performance.