Analysis of a hybrid arch for cost-effective streaming media distribution.

By D. Xu et al.

This paper proposed a hybrid system which combines CDN and P2P streaming. In addition a quantitative model is proposed to analyze the CDN-p2p system: includes hand-off time, remaining requesting peers, total committed p2p streaming capacity and instantaneous p2p streaming capacity(??).

This system is cost-effective.

shortcoming:
Why need to combine p2p and cdn? what is the shortcoming of P2P streaming system?
The hand-off modeling is not incorperated into the protocol design? Some detail of the model is not described and some equation need to be proved.