Study of PPStream Based on Measurement

There have already been many excellent works of measurements and studies on CoolStream, especially PPLive. But few similar works have been done on the PPStream system. In this paper we carried out two relatively large and systemic measurements which resulted in two datasets. We analyzed the PPStream system characteristics based on the two datasets from the aspects of its caching features and data chunk fetching in the startup process of a channel respectively. We find: 1)PPStream has a jumping window for sharing, different from PPLive which has a slipping sharing window; 2) the reciprocal relation between the neighbors is unstable in the network which results in unstable downloading environment. We also find that the chunk fetching emerges a startup characteristic before stable playback.