A Framework for Multimedia Communication in a General-Purpose Distributed System

Abstract : Next-generation distributed computer systems will support network communication of digital multimedia (audio and video) traffic. Evolving hardware technology will provide the necessary performance. However, difficult design issues arise in the software structure of such a system. We consider three related issues: 1) What basic IPC abstractions can accommodate the likely range of traffic types? 2) How can IPC functions such as security and flow control be optimally assigned to system layers? 3) How can host resources such as CPU time and memory be optimally allocated? In response to these questions, we have defined channels, an IPC abstraction with security, reliability, and performance parameters. The channel abstraction underpins the network communication architecture of DASH, an experimental distributed system. In DASH, IPC functions are dynamically assigned to the layer in which they can be performed most efficiently, and the allocation policies for kernel resources are dictated by the performance needs of IPC. All IPC (local and request/reply as well as multimedia) is handled in a single framework.