Modelling the Population Dynamics and the File Availability in a BitTorrent-Like P2P System with Decreasing Peer Arrival Rate

Abstract. Many measurement studies of P2P file sharing systems sug-gest that the request rate for a file changes over time and the system is thus non-stationary. For this reason we study the population dynam-ics and the availability of a file in a BitTorrent-like file sharing system, when the arrival rate for file requests decreases exponentially. We study the system first by a deterministic fluid model and then by a more de-tailed Markov chain analysis that allows estimating the life time of a single chunk exactly. Simple approximation for the life time is also de-rived. In addition, we simulate the life time of a file consisting multiple chunks in order to verify the analytical results to be applicable also to a more complex system.

Peer-level characterization of P2P systems

Mestrado em Engenharia Electrónica e Telecomunicaçõe