Modeling Priority-Based Incentive Policies for Peer-Assisted Content Delivery Systems

Content delivery providers can improve their service scalability and offload their servers by making use of content transfers among their clients. To provide peers with incentive to transfer data to other peers, protocols such as BitTorrent typically employ a tit-for-tat policy in which peers give upload preference to peers that provide the highest upload rate to them. However, the tit-for-tat policy does not provide any incentive for a peer to stay in the system beyond completion of its download. This paper presents a simple fixed-point analytic model of a priority-based incentive mechanism which provides peers with strong incentive to contribute upload bandwidth beyond their own download completion. Priority is obtained based on a peer's prior contribution to the system. Using a two-class model, we show that priority-based policies can significantly improve average download times, and that there exists a significant region of the parameter space in which both high-priority and l...

• Type: Conference
• Year: 2008
• Where: NETWORKING
• Authors: Niklas Carlsson, Derek L. Eager
• Keywords: Computer Networks, Incentive, NETWORKING 2008, Priority-based Incentive Mechanism, Tit-for-tat Policy