ASSIGNMENT 3

Assignment 3



Assignment 3

Introduction

Modern computer networks may consist of thousands of computing devices of various kinds, often made by different vendors and interconnected by many types of transmission media, including standard telephone lines, satellites, digital microwave radio, optical fibres, or digital data lines. They may include local or wide area configurations. For such a group of heterogeneous devices to be linked, both the hardware and software need to be compatible or else complex interfaces need to be built to allow meaningful communication. Network architecture helps achieve this compatibility.

A number of forces are bringing about fundamental changes in the way in which computing technology is applied in contemporary organizations. These include the transformation of society from one primarily dependent on the production of goods to one also much concerned with information and knowledge. Information technology has become a major support to humans and organizations in the development of new products and new services. One major change in organizations is that they have become more horizontal in structure. Reengineering, especially business process reengineering, is often used to accomplish this transformation. Other approaches, such as those based on total quality management (TQM), lead to organizational changes for improved quality and responsiveness. The technological enabler of each of these transformations is advanced information technology. It has enabled the construction of the information-system architecture of an organization to match the reengineered organizational structure and the desire for rapid communications throughout real and virtual organizations. In many cases, these are horizontal structures that require massively parallel communications capabilities between personnel in the organization. Client-server architectures and client-server systems are names generally given to these enablers of these transformations to new structural forms.

Client Server System

A number of important features are incorporated in a client-server system. Clients may access any of a variety of servers, and servers may provide many services. Local- and wide-area communication networks may be used to link geographically distributed servers and clients. Bonding software, or middleware, is used to handle the necessary message routing between clients and servers in the client-server system and is necessary to provide a single system image to a user. This is needed in order for a variety of user applications to run in an environment with multiple vendors such that the system user is isolated from the details of the variety of network communication protocols that may be in use, and such that system users do not need to know where a given set of data is physically located. A server may be a general-purpose computer or a special-purpose machine, or it may be a computer workstation. Client-server computing enables work to be divided across cooperating processors such that clients may use shared resources from many servers to complete a task. Action to engage in an application is generally initiated by a client, and a user-friendly graphical interface is incorporated at each client site. Most client-server systems provide a standard query language at each client site to assist clients in making queries of the ...