To distribute video and audio data in real-time streaming mode, both Content Distributed Network (CDN) based and peer-to-peer (P2P) based architectures have been proposed. However, each architecture has its limitations. CDN servers are expensive to deploy and maintain. The storage space and out-bound bandwidth allocated to each media file are
limited and incur a cost. Current solutions to lowering such cost usually compromise the media quality delivered. On the other hand, a P2P architecture needs a sufficient number of 'seed' supplying peers to 'jumpstart' the system. Compared with a CDN server, a peer offers very low out-bound bandwidth. Furthermore, it is not clear how to fairly determine the contribution of each supplying peer. In this paper, we propose a novel hybrid architecture which integrates CDN and P2P based streaming media distribution. The architecture is highly cost-effective: it significantly lowers the cost of CDN server resources, without compromising the media quality delivered. Furthermore, we propose a limited contribution policy for the supplying peers in the system, so that the streaming capacity of supplying peers is exploited on a limited and fair basis. We present an in-depth quantitative analysis of the hybrid system. The analysis is very well supported by our extensive simulation results.