This article presents two novel protocols for interactive access to video-on-demand systems. They are both based on the well-known BitTorrent paradigm. As main innovative aspects, the video chunks are categorized in different priority sets and there is the deployment of a user-behavior predicting model. The analysis and the validation are carried out through simulations using workloads from a real server. Furthermore, the novel protocols are compared with others of the literature. The final results outline optimizations of up to one order of magnitude over the various competitive metrics considered herein
