Computer systems have become powerful enough to process continuous data streams such as video or animated graphics. While processing power and communication bandwidth of today's systems typically are sufficient, quality of service (QoS) guarantees as required for handling such data types cannot be provided by these systems in adequate ways. We present Switcherland, a scalable communication architecture based on crossbar switches that provides QoS guarantees for workstation clusters in the form of reserved bandwidth and bounded transmission delays. Similar to the ATM technology Switcherland provides QoS guarantees with the help of service classes, that is, data transfers are characterized as variable bit rate traffic or constant bit rate traffic. However, unlike LAN technologies, Switcherland is optimized for cluster computing in that (i) it serves as a backplane interconnection fabric as well as a LAN, (ii) it extends support for service classes by also covering the end nodes of the ne...

: Our vision is an environment that allows (ordinary) PC-clients to profit from a rich collection of multimedia programs such as selected TV channels, video on demand, teleported lectures etc. In this article, we present the design and implementation of a corresponding local infrastructure both from a hard- and software perspective. Innovation highlights are (a) a switch-based network with guaranteed transmission bandwidth for audio/video streams, built-in multicast support and globally accessible display frame buffers, (b) a system for the integrated display of remotely generated video streams at the client site and (c) a central server for the management of the available multimedia programs. Keywords: client/server multimedia system, quality of service, networked peripherals, Oberon. 1. Introduction Thanks to the power, versatility and low cost of today's personal computers multimedia has become an attractive and widespread field of application. The unique combination of high-quali...

We consider the problem of cache management in a demand paging scenario with uniform page sizes. We propose a new cache management policy, namely, Adaptive Replacement Cache (ARC), that has several advantages.

The performance of high-speed network-attached storage applications is often limited by end-system overhead, caused primarily by memory copying and network protocol processing. In this paper, we examine alternative strategies for reducing overhead in such systems. We consider