A video server using ATM switching technology

The video-on-demand (VOD) service is widely notable and the technology to realize the VOD service is regarded as important. In this paper, we propose a video server based on an ATM backbone network. This video server supports VOD service. This video server is composed of an ATM backbone network that links video segment file (VSF) servers storing video data, and sequence control (SC) brokers controlling the reading of video data from VSF servers and supplying video data streams to users. In this system, video data is divided into VSFs and the VSFs are stored on the disks in the VSF servers at random. With this architecture, it is possible to construct various scales of video servers if the number of VSF servers, the number of SC brokers, the number of disk drives per VSF server and the switching capacity are chosen to offer to users the demanded simultaneous accesses at the demanded video data rate. The performance was evaluated by simulation and we clarified that it is possible to support 32 simultaneous accesses at 3 Mbit/s video data. Streams by using one SC broker and one VSF server which has 16 disk drives of 3 MByte/s output rate, and 500 simultaneous accesses is able to be offered by a system which has 16 SC brokers, 16 VSF servers and a 16×16 ATM switch. As a result, we confirmed that a video server of this architecture is realizable from small scale to large scale