Delay Analysis of a Chord-based Peer-to-Peer File-Sharing System

Andreas Binzenhöfer and Phuoc Tran-Gia

Research Report 332

Abstract

In recent years emerging file sharing systems like Gnutella, eDonkey, Overnet, and Kazaa strongly influenced the behaviour of Internet traffic. These platforms employ different peer-to-peer mechanisms, where the application areas are just beginning to shift from undemanding content sharing towards new business case services. Those new requirements brought out new Peer-to-Peer overlay architectures like Chord and Kademlia based on Distributed Hash Tables. The new algorithms satisfy the needs of distributed applications like, e.g. telephone directories supporting ``anywhere'' VoIP. In this paper we investigate the delay of the search process in such a peer-to-peer directory service, where the Chord algorithm is used and the peers are connected through the internet with varying end-to-end transport delay. To guaranty real-time services, quantiles of the search delay are analytically computed. The study also contains the analysis of the scalability of the system, where the impact of the peer population on the search delay characteristic is investigated.