iGridMedia: The system to provide low delay peer-to-peer live streaming service over internet

Commercial peer-to-peer live streaming services are getting popular nowadays, however, almost all systems target non-interactive applications. Few systems can address how to support interactive applications (such as online auction, person interview, video sharing & commenting, etc.) with peer-to-peer streaming technology. In an interactive channel, all or part of the participants can interact with the presenter or publisher at the source. Unlike existing P2P streaming service, there is different level of delay and synchronization requirements in interactive applications, meanwhile, the participant number in each channel is relatively small but the concurrent channel number is large. With such challenges, how much server bandwidth can be saved in P2P streaming is an interesting problem. We propose a very practical protocol iGridMedia and fully implement it. The basic tradeoff between consumed server bandwidth and the required delay is carefully studied. Simulation and real-world experiments show that our system consumes little server bandwidth under low delay even if the peer churn rate is very high and the peer bandwidth resource index is very limited.