An optimal segment replication strategy in P2P-VoD systems

In this paper, we address the problem of content replication in segmented peer-to-peer on-demand systems, with the objective of minimizing the content server´s workload. We consider the system performance under heterogeneous environment. In this P2P-VoD system, multimedia content is divided into segments and peers can seek and cache any segments. Because different segments may be of different popularity, badly designed segment replication may lead to great server´s workload. We deduce the “optimal replication ratio” in segmented P2P-VoD system such that peers will receive upload bandwidth from each other and at the same time, minimize the server´s workload. We formulate the segment replication as an optimization problem and propose a model to solve it. We show that the proportional replication strategy is not optimal for segmented P2P-VoD systems and the segmented system can lead to less server´s workload than non-segmented. We simulate our model, evaluate the performance of segmented P2P-VoD systems and show that our algorithm can greatly reduce the server´s workload.