Provision of fault-tolerant mechanism for peer-to-peer video-on-demand system in broadcast environment

Peer-to-Peer (P2P) communications have become a popular alternative solution to provide large-scale video-on-demand (VoD) services. Recent approaches are designed for streaming applications in a unicast infrastructure. As the successful deployment of IP broadcast delivery, the system could have a further improvement in terms of cost effective and scalability when broadcasting scheme can be coupled with P2P paradigm in a suitable manner. In this paper, we develop a possible solution for building a VoD system using existing broadcasting protocol coupled with P2P paradigm denoted Broadcast-based Peer-to-Peer Protocol with Erasure Correcting Codes (BPP-ECC). A video is partitioned and distributed to a number of peer servers for broadcasting. Because of the dynamic nature of P2P application, a fault tolerant mechanism based on erasure correcting codes is employed to increase the system reliability. To avoid the disruption of service, a central server is still deployed in the system to take over the service when the system does not have sufficient peer server to sustain the service. We thus consider the trade-off between the number of peer servers required and the bandwidth requirement of the central server. An analytical model is developed to determine the minimum number of peer servers required for the system. The results showed that 51 peers, each of which has the availability of 0.6 and has a storage of 288 seconds, are enough to leverage the workload of the central server up to 95%, when the startup delay of the system is 5 minutes.