A Study on Topology Model and Data Contribution Strategy of PPLive

PPLive is one of the successful applications of p2p technology. Understanding the topology model and peer behavior in the PPLive network is an important field of PPLive. Our paper focuses on the data transmission features and the contribution strategy between the peers in the PPLive network. By passive measurement, which is parsing the PPLive data packet, we show that: i) PPLive network has a mesh topology, ii) The bi-directional peer has an absolute advantage both in peer number and the data transmission, iii) According to some reciprocal models, we get that PPLive reciprocal coefficient is about 0.599, which further validates the mesh model of the PPLive network. iv) We try to identify the PPLive network data sharing mechanisms and get the conclusion that a small number of peers contribute the majority of data and the main contributors are stable in both time and flow. Thus the PPLive network has choice and retention strategies based on quality.