Performance optimization of the BitTorrent protocol in the framework of P4P IETF ALTO

Peer-to-peer systems are overlay networks used to distribute content to large sets of users by relying on computing and network resources directly provided by users that are receiving content. The current implementations of such systems are not specifically designed for considering the underlying internet topology or ISP link costs, resulting in a large amount of cross-ISP traffic. In this paper we analyze the impact of two P4P techniques aiming to optimize the distribution of content in the BitTorrent protocol. Results show that the proposed approaches can be beneficial from the ISP point of view. Moreover, the QoS perceived by users does not undergo any significant variation, especially when the load of the network is low.