Performance and Availability Measurement of the IBM Information Network

but no other portions, of this paper may be copied or distributed royalty free without further permission by computerbased and other information-service systems. Permission to republish any other portion of this paper must be obtained from the Editor. IBM SYSTEMS JOURNAL, VOL 22, NO 4 , 1983 Figure 1 Sample of the IBWIN structure IBM products as IBM 3705 communication controllers, Network Control Program (ACF/NCP/VS Release 3), Network Terminal Option (NTO), Network Communication and Control Facility (NCCF), and ACF/VTAM Release 3. The network consists of centralized processors and multitiered local and remote 3705 communication controllers, as illustrated in Figure 1. Thus the design provides the IBM SYSTEMS JOURNAL, VOL 22, NO 4, 1983 capability to support he main network service functions of Remote Computing Services (RCS) and Network Services (NS) in major U.S. cities. The IBM/IN centralized computer complex currently consists of three System/370 processors located in Tampa, Florida, that have two specific functions: BAILEY AND SOUCY 405 1. Two System/370 processors are dedicated as application processors for remote computing services. One processor provides services for the MVS environment; the other provides services for the System/370 VM environment. Services proPerformance and availability requirements have been defined from the point of view of