Net-based Distributed Video-on-demand System

With the development of Internet, it becomes more easily to obtain various kinds of information on Internet. The constant improvement of the bandwidth of the network makes this process more rapidly. Furthermore, increasing demands for the multimedia, such as high-quality video, audio is also getting higher at the same time. Video on demand (VOD) system crossing the field of multimedia and network is the outcome of broadband development. System structure, application and basic research of the VOD are becoming focuses that the industrial and research institution pay close attention to at present. The VOD will change people's normal life in amusement, education, work, shopping and living greatly. The direction of the network multimedia development is to implement and can offer extensive VOD system which can bear the extensive erupting flowing and bring high-quality sound video flowing simultaneously in broadband network at present. In this paper it describes a kind of distributed VOD system with good expanding nature, which distributing the load of the multimedia flowing to the network, utilizing the characteristic of the distributed system .In this way, the bottleneck may appear in the VOD system with single server , eg. input/output load ability and store ability , can be distributed in the network, and enable it to face mass users and offer high-quality video on demand service effectively. Compared with centralized VOD system, distributed VOD system can reach very high service level and have good expansion at the same time even using normal PC as the nod of video server network. First of all, in this paper it introduces the research development at present and Microsoft .NET framework, then analyses the system structure characteristic of the extensive VOD system in the present stage. Secondly, it describes the methods of two kinds of solution, storage technology based on requesting rate and storage technology based on file distributed storage, to balance the load of video server which is the bottleneck of the video server in VOD system. The solution solves how to work in coordination with a lot of servers. Finally, it designs a distributed VOD system based on Mircosoft .NET framework and describes the system structure, core technologies and algorithms, then research the implement of manage server which is the core of the distributed system.