INVESTIGATIONS INTO QoS-AWARE MULTICAST ROUTING IN WIRED NETWORKS

Abstract

Several emerging applications of the current and next generation Internet, e.g. IP radio, IP TV, and video and audio conferencing, etc., involve one-to-many and many-to-many data communications called multicasting. Many real-time applications over IP, such as IP Telephony and video/audio conferencing, cannot operate with the best effort service provided by current IP networks. To support such applications, IP networks need to provide certain quality of service (QoS) assurances. So Multicast (MC) routing algorithms capable of satisfying the quality of service (QoS) requirements of real-time applications will be essential for future high-speed networks. In this dissertation, the performance of QoS-sensitive protocols like QoSMIC, QMRP is compared with QoS-oblivious protocols like DVMRP, PIM-SM, to show that the QoS-sensitive protocols are much suitable to support the real-time applications. The objective of Multiple Constrained Dynamic Multicast Routing is to construct a multicast connection (usually in the form of a shared tree) meeting multiple QoS requirements and should be adaptable to dynamic situations. This is, unfortunately, a NP-complete problem. And the protocols like QMRP and QoSMIC are suitable for single constrained applications but not for multi-constrained. In this dissertation, a multiple constrained dynamic multicast routing algorithm is proposed. The complexity of the problem can be reduced to a simple shortest path problem by applying a Weighted Fair Queuing (WFQ) service discipline. Using a modified Bellman-Ford algorithm, the proposed routing builds a multicast tree without re-routing and satisfying QoS constraints. With user defined lifetime of connection this algorithm builds multicast tree, which is near optimum over the whole duration of