CoopViz: Real Time Visualization of BitTorrent Swarm Dynamics

Peer to peer networks are only successful when a significant amount of users is willing to share their resources. In order to have highly efficient file sharing systems, each user should upload to the other peers a number of bytes at least equal to the number of bytes he has downloaded from the community. Unfortunately many users show a selfish behavior, refusing to offer their upload bandwidth to other peers, thus limiting the efficiency of the networks. P2P clients implement different mechanisms in order to mitigate this misbehavior and improve cooperation; often, though, these policies are not enough to enforce altruism in peer-to-peer communities. This thesis explores a new mean to stimulate users to give their fair contribution to the P2P community; the final scope is to generate an emergent self-policing system where users take active part in determining the bandwidth allocation policies. This is achieved by means of a graphical interface, CoopViz, that provides users with up-to-date insights into cooperative behavior of peers and allows the latter to vote on each other, showing their appreciation or disapproval. Several simulations are presented to support the development choices and to demonstrate the real time behavior of the visualization.