In this paper we present ToroVerde, a novel push-based peer-to-peer (P2P) content distribution application exploiting the digital fountain concept through the use of rateless codes. We provide the protocol specification, then describe the simulator and the complete prototype we have developed for Planetlab deployment and testing. To this end, we consider flash crowd and steady arrival patterns as well as highly churning systems to perform a preliminary analysis of the potential advantages of introducing rateless codes. We present results from PlanetLab experiments compared against performance of BitTorrent, that is widely considered as the reference system for content distribution. We also present a few simulation results showing the behavior of ToroVerde as the number of peers in the systems increases. Our results suggest that ToroVerde has the potential of reducing the average download time for small-to-medium sized files in overlays composed of a few hundred peers with a small increase of the communication overhead.

This paper presents TURINstream, a novel P2P video streaming architecture designed to jointly achieve low delay, robustness to peer churning, limited protocol overhead, and quality-of-service differentiation based on peers cooperation. Separate control and video overlays are maintained by peers organized in clusters that represent sets of collaborating peers. Clusters are created by means of a distributed algorithm and permit the exploitation of the participant nodes upload capacity. The video is conveyed with a push mechanism by exploiting the advantages of multiple description coding. TURINstream design has been optimized through an event driven overlay simulator able to scale up to tens of thousands of peers. A complete prototype of TURINstream has been developed, deployed, and tested on PlanetLab. We tested our prototype under varying degree of peer churn, flash crowd arrivals, sudden massive departures, and limited upload bandwidth resources. TURINstream fulfills our initial design goals, showing low average connection, startup, and playback delays, high continuity index, low control overhead, and effective quality-of-service differentiation in all tested scenarios.