A Measurement Study of PPTV VOD System Based on the Analysis of Client Behavior

This paper conducts a research to PPTV-VOD system with active measurement method based on the reverse engineering and protocol analysis.Firstly,we analyse the protocol of PPTV-VOD to learn its communications data format and semantics.With those knowledge,we can know the working principle of PPTV-VOD system.Secondly,we design and implement a measurement platform based on distribute crawler,exploring the user data in the PPTV-VOD overlay network.In the meantime,we analyse the user data and find out some user characteristics.The research results provide some ideas and methods to monitor and optimize P2P-VOD system.