Maryam Bozorgan - Ministry of Science Research and Technology, Institue for Higher Educatin ACECR, Khouzestan, iran
Behrang Barekatati - Faculty of Computer Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Mehdi Seydali - Faculty of computer and electrical engineering,Tarbiat modares University, Tehran, Iran

In recent years, thanks to the extensive worldwide interactions, it is expected that Internet broadcast video content in anefficient and flexible manner. Peer-to-Peer (P2P) networks, compared to servicing client networks and also based on content distribution,are complex, but more scalable and considerably reduced costs. P2P networks have provided a driving mechanism in which uploadcapacity of peers can be in accordance with the effective delivery of a network service. In some extent, bandwidth capacities and systemmemory of end-users also are used in overlay P2P network and content distribution load is transferred from servicing and networkcomponents to end users of the system; and since administration of overlay P2P networks is as a distributed management, the manner ofconnection weaknesses handling and the way the peers cooperate would impact on the quality of the received video. In this review study,the Peer-to-Peer video streaming system is investigated along with challenges posed by it as method of streaming video, the heterogeneistyof bandwidth, congestion in the network, resiliency, node churn, traffic control and the quality of cooperation among distributor andrequesting peers, and consequently selfish peers and free riders as well as the effect of mentioned issues on quality of received videos andoptimum solutions to eliminate or reduce the effects of free riders. Finally, an efficient comparison is made for a variety of proposedsolutions by which we can realize the advantages and disadvantages of each method, representing this as an effective key to future efficientsolutions.

p2p network, free rider, incentive mechanism, selfish behavior