High-Speed Network Support for High-Performance Network Computing and Multimedia Communications

The prevalence of computer networks has shifted the computing paradigm from mainframe or host-centric computing to network-centric computing. In networkcentric computing, applications are executed distributedly on a collection of computers interconnected via local and wide area networks. The performance of networkcentric applications can be dramatically improved with switch-based high-speed networks, such as HIPPI, ATM, and Fibre Channel. In this study, we focus on the high-speed network support for two important applications in network-centric computing: high-performance network computing and multimedia communication. One important class of network computing is cluster computing, which enables a collection of locally interconnected computers to be used as a general-purpose parallel computing system. Large problems can be solved cost effectively by using the aggregate processing power and memory space of a cluster. However, communication between processors has long been the bottleneck of cluster computing. We have especially concentrated on maximizing the achievable throughput and minimizing the communication delay for cluster computing in homogeneous environments. We have enhanced a popular cluster computing environment, Parallel Virtual Machine (PVM) with clusters of workstations on either local ATM or HIPPI networks. One possible extension of cluster computing is to incorporate clusters of computers via wide area networks. This is called meta-computing. For example, a group of diverse high-performance computers from several geographically distributed supercomputer centers can be employed to solve large problems. ATM is the de facto standard for wide area networks. However, most of the supercomputer centers use HIPPI in their computing facilities. The internetworking of HIP PI networks and wide area ATM networks becomes an important issue for met a-computing. Two feasible solutions for the problem, HIPP! Tunneling and IP Routing, have been studied in this thesis. Multimedia communication imposes another challenge for high speed networks. The delivery of continuous media requires high communication bandwidth and realtime constraint. Ve have studied two new CBR transmission schemes, called PCRassist CBR (PCBR) and PCR-assist Dual-Rate CBR (PDCBR), which employ the Program Clock References (PCR) embedded in the MPEG-2 Transport Streams to regulate their transmission. The two schemes provide flexible trade-off between buffer requirement and transmission rates

Enhanced PVM Communications over a HIPPI Local Area Network

With the emergence of switch-based high-speed local area networks (such as HIPPI, ATM, and Fibre Channel) and powerful workstations, distributed network computing becomes more feasible for large-scale scientific and engineering applications. Most of the distributed algorithms are implemented based on the message passing model. In a local area network environment, fast message passing can be achieved by employing high-speed networks and reducing the overhead of protocol processing. In this paper, we present a study of improving Parallel Virtual Machine's (PVM) communication performance over a HIPPI local area network. After a detailed examination of PVM's communication subsystem, we re-implemented PVM using the Hewlett Packard's Link Level Access (LLA) interface instead of the BSD socket interface which was originally used by PVM. From the experimental results of the performance evaluation, our study demonstrates the potential and feasibility of high-performance network computing over a high-speed switch-based local area network

Distributed Network Computing over Local ATM Networks

Communication between processors has long been the bottleneck of distributed network computing. However, recent progress in switch-based high-speed Local Area Networks (LANs) may be changing this situation. Asynchronous Transfer Mode (ATM) is one of the most widely-accepted and emerging high-speed network standards which can potentially satisfy the communication needs of distributed network computing. In this paper, we investigate distributed network computing over local ATM networks. We first study the performance characteristics involving end-to-end communication in an environment that includes several types of workstations interconnected via a Fore Systems' ASX-100 ATM Switch. We then compare the communication performance of four different Application Programming Interfaces (APIs). The four APIs were Fore Systems ATM API, BSD socket programming interface, Sun's Remote Procedure Call (RPC), and the Parallel Virtual Machine (PVM) message passing library. Each API represents distribute..