Impact of node architecture on network performance
Fred Prior, Klaus Niggenaber, Shahram Khosravani, Glenn Meredith · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1990
The first parameter of interest in considering network performance is signaling rate. To understand end-to- end image transfer rate, however, signaling rate is often the parameter of least importance. The basic image transfer in a PACS is disk-to-disk or at best disk-to-memory. The real performance bottlenecks are disk and system bus I/O rates, CPU and operating system efficiency in executing network protocols, and throughput of network interface units. Except for issues of congestion, the end-to-end performance of a 100 Mbps FDDI net may not be significantly different from that of a 10 Mbps Ethernet. The system architecture of workstations and storage nodes is the key to overall PACS network performance. Simulation studies indicate that a high speed disk subsystem combined with an intelligent network interface unit avoids the bottlenecks associated with conventional systems and can make use of high bandwidth media such as broadband ISDN. Experience with a preliminary demonstration of broadband ISDN connectivity as part of the Berlin Communications (BERKOM) project will be presented.