Multicast Routing Algorithms In Computer Networks

In computer networks, to provide multicast for multimedia real-time service, such as distance education and videoconference, is one of the important issues in current research field. Multicast routing is a network-layer function that constructs paths along which data packets from a source are distributed to reach many, but not all, destinations in a communication network. A fundamental issue in multicast communication is how to construct low-cost trees that will satisfy the Quality of Service(QoS) requirements and spanning all destinations. The paper centers on the algorithms which can construct low-cost multicast routing trees with QoS requirements and several multicast algorithms are proposed in the paperThe main research work and results are follows:1. The existing heuristic algorithms for Steiner tree problem are summarized.2. Propose three algorithms for delay-constrained multicast routing. The first one is multicast routing algorithm based on adaptive Ant Colony algorithm, which is based on adaptively adjusting the pheromone on routes. The second one is multicast routing algorithm based on Clone Selection algorithm, Clone Selection algorithm is a global optimization algorithm and can improve the performance of multicast tree. The last one is delay-bound constraint multicast routing algorithm based on Clone Selection and Ant Colony algorithm, it overcomes the drawbacks of slow convergence rate and easily falling into the local optimum. The theory and result of simulations show that improved algorithm is better than ant colony algorithm and solving the global optimization problem, and the convergence speed is improved greatly.3. To improve the performance of multicast tree, a rearrangement dynamical multicast routing based on Clone Selection is proposed. A region of multicast tree degraded to a certain extent, rearrangement must be initiated. The simulations show that the performance of improved multicast tree is steady relatively and is not worsen.4. To suitable for multicast routing in the network of Internet, the hierarchical multicast routing algorithm based on Clone Selection algorithm is proposed in the paper. The simulation shows that the algorithm is of better performances, reduce the complexity of time and storage space, improve the expansibility and save network resources.