Multicast routing algorithm under QoS constrained network environment

Abstract

In high speed networks, multicast is becoming an important requirement to support multimedia services. Multicast applications, such as audio- and video conferencing, collaborative environments and distributed interactive simulation, by and large, involve a source sending messages to a selected set of destinations with varying Quality-of-Service (QoS) delivery constraints. This requires the underlying network to provide multicasting and QoS capabilities to efficiently support these applications. QoS parameters are used to express the applications`` requirements that must be guaranteed by the underlying network. Hence, the importance of multicast routing algorithms to satisfy the QoS requirements of each individual application is increasing. In this thesis, we studied the relation between constrained algorithm and QoS. The unconstrained and constrained problem of least loaded routing in ATM networks was discussed. As a result we know that the constrained algorithm satisfies QoS requirement. Therefore we apply constrained algorithm to multicast routing for QoS. We survey some related works in multicast routing algorithm and considered these for real time applications, especially focusing on unconstrained and constrained algorithms. Finally we propose an efficient multicast routing algorithm that has QoS constraints. In order to support real-time applications, several delay-constrained heuristics have been proposed in multicast routing. These delay-constrained algorithms try to heuristically construct a low cost tree subject to a given upper bound on end-to-end delay. However, some of these heuristics may fail to provide a low cost tree as they assume that network links are symmetric. Furthermore, the time required to construct such a tree may be prohibitive, especially for large networks, as they employ a breadth-first search algorithm to find feasible low-cost paths or iteratively replaces the edges in the tree until the tree cost cannot be further reduced. ...