Network aware very large data multicast

Abstract

Recently, needs for fast dissemination of large size data to multiple receivers are growing. Multicast is an efficient transmission scheme for those dissemination. Contrasted with unicast, where multiple point-to-point connections must be used to support communications among a group of users, multicast is more efficient because each data packet is replicated in the network - at the branching points leading to distinguished destinations, thus reducing the transmission load on the data sources and traffic load on the network links. To implement multicast, networks need to incorporate routing and forwarding mechanisms in addition to the existing unicast methods. Unfortunately, the necessary functions needed to realize multicast are not fully deployed in the current networks. Overlay multicast holds promise for the realization of large scale Internet multicast services. An overlay network is a virtual topology constructed on top of the Internet infrastructure. The concept of overlay networks enables multicast to be deployed as a service network rather than a network primitive mechanism, allowing deployment over heterogeneous networks without the need of universal network support. This dissertation addresses the large size data dissemination problem in the overlay network. We propose a network-aware overlay multicast (NAM) technique for large data transfer in a well-managed overlay network. To improve the throughput, NAM uses forward-only hosts; these hosts participate in the overlay network but are not members of the multicast. With the inclusion of the forward-only hosts, data slices can detour bottleneck links and more resources can be used to build efficient multicast trees. Large data are divided into fixed-size slices, and the slices are delivered simultaneously to multicast receivers along the multiple multicast trees. We model the problem of building efficient multicast trees with the inclusion of forward-only hosts. The problem is an NP-hard problem, and...