Systems aids in determining Local Area Network performance characteristics

Abstract

At Bethesda, Maryland, the National Library of Medicine has a large array of heterogenous data processing equipment dispersed over ten floors in the Lister Hill Center and four floors in the Library Building. The National Library of Medicine decided to implement a more flexible, expansible access medium (Local Area Network (LAN) to handle the rapid growth in the number of local and remote users and the changing requirements. This is a dual coaxial cable communications system designed using cable television (CATV) technology. One cable, the outbound cable, transfers information between the headend and the user locations. The other cable, the inbound cable, transfers information from the user locations to the headend. This system will permit the distribution of visual and digital information on a single medium. On-line devices, computers, and a technical control system network control center are attached to the LAN through BUS Interface Units (BIUs). The technical control system will collect statistical and status information concerning the traffic, BIUs, and system components. The BIUs will, at fixed intervals, transmit status information to the technical control. The Network Control Centers (NCC) will provide network directory information for users of the system, descriptions of the services available, etc. A X.25 gateway BIU will interface the LAN to the public networks (Telenet and Tymnet) and to X.25 host computer systems.