The Research Of QoS-Aware Multicast Routing Algorithm And Protocol

With the development of Internet,the recent emergence of multimedia communications and cooperative works in distributed environments provides an incentive to system designers to include multicast communication support for these applications.A fundamental issue in multicast communication is how to determine an efficient multicast routing,namely in search of simple, effective and robust multicast routing algorithms.Multicast routing algorithms are used to compute multicast trees that satisfy quality of service requirement.The problem in search of multicast routing with QoS-aware is a NP-Complete problem,so the problem is very difficult to solve.Thus, most previous researchers have focused on developing heuristic algorithms and using the classical algorithms such as Genetic Algorithm and Simulated Annealing to solve unconstrained and delay-constrained multicast routing problem. However,these classical algorithms have high computation complexity so they are not fit in practicality.First,this dissertation introduces the present research conditions of the QoS routing technology and it's related theories,given a survey of QoS multicast routing algothrims and protocols at home and abroad.Based on the interconnected conditions of node in the Internet, a multicast model of n-level forwarding table is proposed to solve QoS-aware multicast routing problem.An architecture is used,every node maintains a n-level forwarding table which contains information about its neighbors and QoS aiming at alleviating the memory overhead of routers for setting up multicast trees and improving network scalability of the protocol.we deeply discuss one-level forwarding table QoS multicast protocol based on bounded flooding technique and distributed computation,named QDVMRP.A very efficient integrated heuristic function which can be used to optimize multicast delay,bandwidth and network cost to some extent was proposed in this paper.It shows the effectiveness of this multicast protocol by evaluating the protocol's performance in terms of the average control messages and the average call acceptance ratio through simulation.At last,we researches the mechanism of integrating the QDVMRP with an admission control algorithm using delay and bandwidth as the parameters.It can be used in the reduced service-set architecture supporting load-controlled service,guaranteed service and best-effort service.