Research And Simulated Implementation On Ant-Colony-Algorithm-Based Fault-Tolerant Routing Mechanisms In IP/DWDM Optical Internet

With the rapid growth of Internet and the improvement of social informationization degree, some new-type multimedia applications emerge constantly, such as E-commerce, virtual reality, digitized library, distant education and video conference etc. The demand of network bandwidth is enormous because of the expandig global Internet-based services. IP/DWDM optical Internet will play an important role in the next generation Internet for the preponderance of DWDM technology on efficiently utilizing tremendous bandwidth of fibers. Due to multiple wavelength channels aggregate onto one fiber, DWDM networks are more sensitive to component failures. The operations of terabits per second (Tbps) will be interrupted by a broken fiber in IP/DWDM optical Internet. So how to improve the fault-tolerance of IP/DWDM optical Internet becomes the problem badly in need of solution. Fault-tolerant routing mechanisms are one of the effective methods to solve the problem.In this paper, the research mainly focuses on fault-tolerant routing mechanisms in the case of single-link failure. The ant-colony algorithm is used to solve the problem of QoS(Quality of Service) fault-tolerant routing in IP/DWDM optical Internet. In allusion to unicast fault-tolerant routing, the objective is to minimize the number of orphans. The ants are clssified into two kinds to establish link-disjoint primary and backup lightpaths for the dynamic lightpath connection request. The multiplexing technique is used to improve the resource utilization ratio of the network and to reduce the blocking probability of the lightpath connection request. The crossover operator of genetic algorithm is adopted to jump out the local best. As to multicast fault-tolerant routing, the aim is to minimize the link fault probability of multicast tree. The primary and the backup trees are established to realize muliticase fault-tolerant. The QoS negotiation with user is necessary when the backup tree that satisfied the QoS is not found.To verify the correctness and the feasibility of the ant-colony-algorithm-based fault-tolerant routing mechanisms, a simulated implementation is made with NS2. The...