A COMPUTER-AIDED METHODOLOGY FOR THE DESIGN AND ANALYSIS OF DATA COMMUNICATION NETWORKS

摘要

The increase in the interconnection of computers has led to a corresponding increase in the complexity of effective network design. This increase is partly to the size and diversity of computer networks, but also is due to the proliferation of available network hardware and software. As with any system, computer networks are made up of various interrelated components, all of which are essential to the network design process. Some of these components are physical in nature, that is, they specify a piece of hardware or software with certain perfomance properties. Other components are considered to be logical elements of network design. The problem of designing, implementing and controlling present and planned data communication networks is rapidly exceeding manual planning and design capabilities. Network managers and designers are looking more and more to computer resources to manage the volume of traffic information, to develop and evaluate network configurations, and to assist in allocating and placing control functions among network processors. The number of network alternatives is increasing so fast that the demand for network optimization--both in private network design and in the interface to, and use of, public network facilities--can be satisfied only through computer aids. These aids range from simple scratch-pad systems that store and compile network statistics to complete traffic emulators, design configurators, and software for data-distribution modelling. Network design generates a set of performance/cost tradeoffs for an existing or proposed network. The network design process generates and regenerates these performance curves in response to changes in critical design parameter such as protocols, line capacity, concentration points, host processor capability and message routing techniques. This dissertation considers the development of a generalized model of the network design process. This model proposes that the physical and logical network components can be described using a set of objects, properties and relationships. Objects are used to describe network physical and logical components. These components are given properties, thus associating with each object a set of network descriptions. Linkages between objects or classes of objects are provided by object-object relationships. The prototype system provides a generalized network design tool which allows a concise and explicit statement of network requirements providing a network planning and design model which is independent of any particular network or application.