A measurement study of PPStream

In this article, we first review the evolution of Peer-to-Peer (P2P) file sharing and media streaming systems, and then focus on one of the most popular P2P-based media streaming services - PPStream. We describe the PPStream protocol discovered through reverse engineering efforts and discuss our measurement study conducted to evaluate three aspects of the system: privacy, locality, and availability. The experiments reveal that PPStream is vulnerable to privacy exploits and is not locality-aware when selecting peers to exchange media packets. The study also finds that PPStream is fairly robust against packet filtering-based Denial-of-Service (DoS) attacks that target its channel discovery, peer registration, and peer discovery protocols.