SNA multiple-system networking

摘要

The central theme of this paper is that SNA provides network services that simplify the design, implementation, and operation of distributed processing applications. It does this through support of: • Twenty-four-hour operation. The reduction of System Services Control Point cross-domain LU definition, multiple active routes, dynamic configuration, shared control, and the self-adjusting algorithms that perform flow control are all directed to reducing the number of times when a portion of the network needs to be taken off line for modification. • Any configuration. Cross-domain session services, shared control, dynainic configurution, parallel links, configuration insensitivity, multiple active routes, and control point take over all enlarge the user''s choice of network configurations. The extra degrees of freedom that this provides can be used to increase availability, and reduce costs. • Usability and availability. Communications network management, session outage notification, control point restart and takeover, session restart, multiple active routes, class of service and flow control all improve the usability and availability of the network. The growth of the network architecture to provide many functions was discussed. Since products implement only those functions needed bu their users, not all products have implemented all functions. A partial summary of product support of SNA is contained in Table l.