SYMPHONY: A Hardware, Operating System, and Protocol Processing Architecture for Distributed Multimedia Applications

This paper explores the architectural requirements for computers to be able to process multimedia data streams such as video and audio. The I/O subsystem is shown to be a bottleneck, and a network backplane approach is suggested to alleviate this. The need to provide end-to-end performance guarantees requires predictable performance of intra-machine communication, and a schedulable bus with reservation is proposed to achieve this. In addition this requires operating system (OS) mechanisms to negotiate and enforce QoS requirements of applications. A real-time microkernel executive is proposed for each autonomous unit. Requirements for real-time microkernel exeutive is proposed for each autonomous unit. Requirements for real-time scheduling and efficient interprocess communication mechanisms are described. Finally the implications of the hardware and OS enhancements for the protocol procesing mechanisms are discussed. A compositional approach to protocol organization that is capable of catering to the wide variations in transport requirements of various media is described