Operating System Support for continuous media in an ATM environment

• Main Author: Zeadally, Sherali
• Published: University of Buckingham 1996
• Subjects: 621.3821
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.601340

The past decade has witnessed great strides in the networking field . New technologies such as fibre optics and ATM have made it possible to build networks with speeds ranging from hundreds of megabits to gigabits per second. There has been a. rapidly growing class of I/O intensive applications, such as those manipulating multiple media, made possible by the dramatic increase in hardware performance, and decreasing costs of computer hardware. Increasing network bandwidth is not leading to commensurate improvement in performance of end-user applications. The bottleneck lies within the end-hosts (workstations and servers) and is partly due to a lack of integration between the host network interface and the operating system. In addition, most current operating systems do not support I/O intensive applications well because they cannot transfer voluminous amounts of data efficiently. This is because improvements in memory performance have not kept pace with improvements in processor performance. The aim of this work is to improve operating system support for continuous media in the context of high-speed networks. An ATM host-interface has been built to enable both multimedia. and traditional data streams To be handled on general purpose operating systems. New process and memory models that provide a better integration of the operating system with the network interface are presented . This is achieved by using a memory mapped network interface. In order to evaluate the real-time performances of current operating systems, the effects of context switch times and interrupt latencies have been investigated. New data streaming styles are proposed to reduce or eliminate these overheads. The viability of the different techniques has been demonstrated by implementations and performance measurements. It is shown that with a careful integration of the operating system and the network interface it is possible to minimise or eliminate conventional overheads resulting from data copying, interrupt servicing and context switches.