Tomohisa Yamaguchi

Poster on a distributed RAID VOD system

Summary form only given. We present an implementation of a VOD (video on demand) system that addresses the problem of increasing video stream supply capabilities. To obtain fundamental video stream transfer characteristics on Ethernet, we first performed an experiment in which it became clear that bottlenecks of the CPU of a video server were the most serious. To solve this problem we implemented a distributed RAID4 (Redundant Arrays of Inexpensive Disks) method video server. Distributed RAID means extending the RAID method usually applied to disks to the servers, so as to achieve improvements in performance and reliability. The great advantage of this architecture is that the linear performance improvement can be achieved by adding inexpensive servers of a diffusion model.

Prototype system of secure VOD

Secure digital contents delivery systems are to realize copyright protection and charging mechanism, and aim at secure delivery service of digital contents. Encrypted contents delivery and history (log) management are means to accomplish this purpose. Our final target is to realize a video-on-demand (VOD) system that can prevent illegal usage of video data and manage user history data to achieve a secure video delivery system on the Internet or Intranet. By now, mainly targeting client-server systems connected with enterprise LAN, we have implemented and evaluated a prototype system based on the investigation into the delivery method of encrypted video contents.