An Efficient Streaming Method in Overlay Multicast
Networks Suk Kim Chin · 2009
The predominance of unicast connectivity in the current Internet infrastructure sabotages the widespread deployment of video applications. As such overlay multicast networking has been proposed to accelerate the ubiquity of video streaming in the Internet. Based on an existing overlay multicast network architecture, this paper proposes a method which aims at improving the efficiency of the streaming scheme that is part of this architecture. Instead of sending multiple streams of the same data across the network, only the essential video signals are sent in redundancy. Evaluation of the method generates promising results in preventing loss of the essential video data in burst losses of packets. For the majority of Internet user community, the most appealing applications are audio and video. Video is the ideal fit for the Internet. While text and pictures do well to convey ideas, video provides the most natural, comfortable, and convenient method of human communications. Even the least dynamic examples of video reveal infinitely more than the audio-only versions (1). The original Internet infrastructure cannot support the requirements of desirable emerging applications such as Internet TV. With the exponential increase of its user community, it is also impossible for the current Internet to support the diverse range of group and collaboration applications (such as video conferencing and interactive multimedia educational systems) without driving it into momentary meltdowns. The nature and diversity of these group applications require the underlying system to support varying demands in the dimensions of bandwidth, latency, reliability, multiple sources, scalability and system dynamics. As the Internet is predominated by unicast connectivity, it is incapable of satisfying these requirements. Thus IP multicast (2) was proposed in the late 1980's to support transmission of audio / video data more efficiently than unicast. Unicast transmits one copy of data separately to each member of a group whereas a multicast data source only sends one copy of data, which is replicated as necessary when propagating in the communication channels towards the receivers. Thus group communications are enabled without traffic explosion in the network. However, deployment of IP multicast is still non-ubiquitous due to a multitude of issues, including the complexity of its protocols. Frustrated with the lack of success in widespread deployment of IP multicast, researchers have turned to deploying multicast technology in the application layer, resulting in the emergence of a myriad of techniques collectively called overlay / application layer multicast. These techniques are designed to give versatile multi-dimensional support through the underlying transport