Eşler arası epidemik içerik dağıtım protokol dizaynı ve performans değerlendirmesi

Peer-to-peer (P2P) cooperative systems are becoming extremely popular as they finddiverse applications. One major application area is the content distribution over large-scale networks. As the usage of the Internet grows up, the number of large contents suchas software packages and popular movie files, and also the user population retrievingthese contents increase exponentially.In this thesis, we propose and design a peer-to-peer system, SeCond, addressing thedistribution of large sized content to a large number of end systems in an efficient andeffective manner. In contrast to prior work, it employs an epidemic dissemination schemefor state propagation of available blocks and initiation of block transmissions. In order tosupport heterogeneity of peers, ease of deployment, scalability, and adaptivity to dynamicpeer arrivals/departures, and also to increase the utilization of the system resources, wepropose mechanisms such as adjusting protocol parameters according to the bandwidthusages dynamically. We describe our protocol SeCond and its discrete event simulationmodel. A comprehensive performance evaluation has been accomplished for a wide rangeof scenarios. A well known and widely used P2P content distribution system isBitTorrent which we also model and compare as a benchmark. Performance resultsinclude scalability analysis for different arrival/departure patterns, flash-crowd scenario,overhead analysis, and fairness ratio. The major metrics we study include the average filedownload time, load on the primary seed, uplink/downlink utilization, communicationoverhead, and the fairness ratio. SeCond peers download the file faster compared toBitTorrent peers for most of the scenarios and the protocol is as fair as BitTorrentalthough it has no explicit strategy addressing free-riding. We show that SeCond is ascalable and adaptive protocol which takes the heterogeneity of the peers into account.We also illustrate the applicability of an analytical fluid model to the behavior ofSeCond.