The Delicate Tradeoffs in BitTorrent-Like File Sharing Protocol Design

The BitTorrent (BT) file sharing protocol is popular due to its scalability property and the incentive mechanism to reduce free-riding. However, in designing such P2P file sharing protocols, there is a fundamental "Tussle" between keeping peers, specially the more resourceful ones, in the system for as long as possible to help the system achieve better performance and allowing peers finish their download as quickly as possible. The current BT protocol represents only "One" possible implementation in this whole design spectrum. In this paper, the authors characterize the "Complete" design space of BT-like protocols.