Uma arquitetura usando trackers hierárquicos para localidade em redes P2P gerenciadas (original) (raw)

Peer-to-Peer (P2P) networks have become an attractive method for distributing multimedia content over the Internet in the last years. Several factors contributed to this success, but the low distribution costs and the inherent scalability of P2P networks, in which content consumers are also potential sources, are among of the most prominent. However, the effectiveness and performance of several popular P2P networks (such as those that use the BitTorrent protocol) is considerably dependent on how well the tracker (which is the element responsible for the identification and management of participants in BitTorrent P2P networks) selects peers that will provide the content. The peers chosen by the tracker will directly affect the user's perception about the service performance and proper deployment of the of network resources. In addition, P2P networks usually have no sense of locality, resulting in a non-optimal utilization of network resources. In order to address these issues, this thesis presents a novel hierarchical tracker architecture using P2P locality for managed networks based on a modified version of the BitTorrent protocol. This thesis shows, through experimentation, that the adoption of the proposed architecture leads to significant network efficiency improvements without compromising end-user experience. Among the improvements, the principal is the data flow control between the peers through the choice of peers given by tracker based on network information and business rules. This enhancement allows to manage the network proactively and to perform dynamic adaptation of the network due to adverse conditions. The network control can be achieved by setting policies that are driven by predetermined triggers. This thesis uses time-based triggers (date / time) to exemplify the approach of programmable policy change.