Differentiated Bandwidth Allocation for Reducing Server Load in P2P VOD

P2P technology offers a promising scalable solution for video-on-demand (VOD) service. Recent studies have found that departure misses are the major cause of server load in P2P-based VOD. Inspired by this finding, this paper addresses the design of bandwidth allocation policy to decrease departure misses and thereby reduce server load further. We first formulate the minimum departure misses problem. Then we propose a centralized algorithm which serves as our benchmark for all other schemes. The centralized algorithm makes use of surplus bandwidth to help peers prefetch chunks, thus reducing departure misses significantly. We then propose a distributed bandwidth allocation algorithm in which a stable peer with higher playback position is able to obtain a larger share of parentspsila upload bandwidth. A simple predictor is developed for stable node identification. Simulation results show that our distributed protocol outperforms traditional approach, and close to the centralized one.