Abstract
The number of live multimedia streaming applications is increasing, explaining the use of many overlay network topologies. A P2P-based multimedia streaming system, called Live2006, provides a scalable, robust, and high available live streaming service. Based on the concept of Application Layer Multicast, a tree-based structure is designed to connect the peers, and the peers share the receiving streaming to reduce network traffic. Live2006 can not only efficiently reduce the loading of the streaming server, but also minimize the cost of constructing a complete distance education system to support large number of users. The proposed Live2006 system can also be established for home or community networks to reduce the usage of downloaded bandwidth. A high level quality of service is maintained even if a significant number of individuals are watching the same program. Live2006 also provides the streaming services for users using the private IP addresses behind an NAT (Network Address Translation). Thus, users can easily access the programs through their devices, including the resource limited handset devices, in anytime and anywhere without constraint. Additionally, since Live2006 is a multimedia data transmission framework, it is easy to integrate with existing distance education service systems with only a few changes. Live2006 not only operates under IPv4 environment, but also works in IPv6 network. Some IPv6 features, such as IPv6 mobility (provides handset users better service) and anycast (provides better system efficiency) even perfects the functionality of Live2006. Although Application-Layer Multicast (ALM) has attracted much attention in transmitting multimedia, it has a serious problem: the multicast tree is fragile and a peer failure will cause tree partitions. This work presents a novel Hierarchical Ring Tree (HRT) architecture for Peer-to-Peer (P2P) live multimedia streaming. The proposed architecture combines ring-based and tree-based structures in a robust, scalable, reliable and resilient structure that can be used practically as an ALM topology. When peers enter or leave the system, the topology is recovered rapidly such that live multimedia stream can be delivered smoothly with a low latency. The proposed HRT topology is constructed and maintained efficiently without splitting or merging trees. The performance of the proposed architecture and algorithms is evaluated experimentally. Experimental results indicate that the proposed topology can be used in a high-churn P2P network with a small delay. Simulation and experiment results reveal that the proposed architecture has a lower overhead than the ZIGZAG approach when handling peers’ joining or leaving, exhibits faster recovery, better quality of service during streaming, and a more robust topology, even with an extremely large number of peers joining/leaving.