This document provides an overview of computer networks and the Internet. It defines computer networks and describes their basic components like clients, servers, and telecommunications equipment. It explains how the Internet works as a worldwide network and discusses technologies like intranets and extranets. The document also covers the evolution of networking technology from mainframes to today's ubiquitous IP networks, and the role of the Internet in restructuring business relationships through disintermediation and re-intermediation.

1. Chapter 5 Networks, telecommunications and the Internet

4. Figure 5.1 Communications links between different stakeholders in an industry

9. Figure 5.3 Components of a client/server system

14. Examples of different servers Network Contains functions to manage the network resources and control user access File This term is sometimes used to refer to network server functions. It can also indicate that users’ files such as documents and spreadsheets are stored on the network server Print Dedicated print servers have a queue of all documents for which print requests have been made, often combined with file or network servers Fax Used to route incoming and outgoing faxes received and sent from the users’ desktop Mail Stores and forwards e-mail messages Database Used to store data and provide the software to process data queries supplied by users, often accessed by Structured Query Language (SQL) Application Used to store programs such as spreadsheet or bespoke applications run by end-users on their PCs. This removes the need to store each application on every user’s hard disk Communications Manages connections with other networks in a WAN configuration. Sometimes known as gateways and attached to other gateway devices such as routers and firewall servers.

23. A Simple Computer network

36. Figure 5.4 Infrastructure components of the Internet Source: Chaffey (2004).

38. Figure 5.6 B2B and B2C interactions between an organisation, its suppliers and its customers Source: Chaffey (2004).

40. Figure 5.7 Summary of transaction alternatives between businesses and consumers Source: Chaffey (2004).

42. Figure 5.8 Disintermediation of a consumer distribution channel showing (a) the original situation, (b) disintermediation omitting the wholesaler and (c) disintermediation omitting both wholesaler and retailer Source: Chaffey (2004).

44. Figure 5.10 The move to re-intermediation: (a) original situation, (b) disintermediation, (c) re-intermediation Source: Chaffey (2004).

47. Figure 5.12 The relationship between intranets, extranets and the Internet

50. Figure 5.14 An example of the use of firewalls to increase security within an e-business infrastructure Source: Chaffey (2004).

53. Figure 5.15 Information exchange between a web browser and web server Source: Chaffey (2004).

57. Figure 5.16 The TCP/IP protocol Source: Chaffey (2004).

66. Figure 5.24 A small workgroup network connecting a single server to three PCs and a laser printer