LEARNING OBJECTIVES
● To understand the importance of technology.
● To be able to explain the basics of networking and related technical jargon.
● To identify the different kinds of networks architectures and their uses.
● To understand the origins of the Internet and its strengths and weaknesses as an infrastructure.
● To understand the structure of the Internet access provider industry.
● To be able to identify the different ways of connecting to the Internet and their respective advantages and disadvantages.
WHY BOTHER WITH THE TECHNOLOGY?
The IT community seems to have developed a language of its own, full of buzzwords and jargon, which often obscures understanding for the non- technical. The aims of this chapter are to explain the technology and language of e-commerce and its relevance to business.
In the UK, the Commons Public Accounts Committee published a report1examining over 25 cases of government IT projects from 1990–9.
The report identified why the implementation of public sector IT systems resulted in delay, confusion and inconvenience to the citizen and led to taxpayers’ money being wasted or providing ‘poor value for money’.2Some of the projects included:
● The Home Office– a £77 million computer system designed to stream- line asylum applications had to be abandoned by the government after it failed to meet a growing backlog of applications.
national insurance payment led to 17 million contribution payments not being registered on claimants’ records. Over 170,000 pensioners were underpaid their pensions. The final compensation bill was estim- ated at £40 million by the National Audit Office.
Such failures not only happen in the public sector, but also in the private sector. The London Stock Exchange (LSE) experienced similar problems in the mid–1990s, when the £400m Taurus project to implement a new back office system in-house collapsed because of numerous problems and delays. In April 2000, a time of unusual turbulence in international stock markets and also the end of the English tax year, the LSE, whose computer programs were managed by Andersen Consulting (now Accen- ture), experienced a fault that caused its share trading system to collapse for eight hours, losing millions of pounds worth of business and damaging its reputation. It was discovered that an error between two computer programs had resulted in the system transmitting share prices before they had been updated.4
These are just a few high-profile examples of the kinds of problems that are experienced by IT systems and projects and the consequences that can arise because of them. One of the key recommendations from the report states that, ‘Key decisions on IT systems are, therefore, business decisions, not technical ones, and should involve senior management. And the commitment of senior management can be a critical factor in securing a successful outcome.’5 It is often the case, though, that senior manage- ment and other business managers distance themselves from anything to do with IT and seem to pass the responsibility to technical managers. This is not just a UK phenomenon, as these experiences are duplicated in the rest of Europe and America.
A study by Professors Bensaou (INSEAD) and Earl (London Business School) compared Western and Japanese IT-management practices.6 It found that Japanese companies rarely experience the IT problems so common in the USA and Europe mainly because of how Japanese and Western managers think about technology. The Japanese see IT as just one competitive lever amongst many. Its purpose is to help the organisation achieve its operational goals, so the Japanese bias is to adopt appropriate
technology rather than adopting technology for technology’s sake. Jap- anese managers were found to spend two to three years in the IT depart- ment, often against their will – so sometimes the director of finance and the director of IT planning is the same person. While acknowledging that Japan has its own weaknesses with technology, particularly in white-collar office settings, the study nevertheless urges senior managers in the West to consider the solid foundation on which Japanese IT management rests:
‘Abandon the dangerous idea that IT requires special technocratic means of management.’7Too many managers in the West are intimidated by the task of managing technology and feel that they can comfortably pass on the responsibility to the IT department.
It is therefore crucial that business managers understand the techno- logy and are confident in that knowledge to be able to ask critical questions and make critical decisions. The remainder of this chapter will introduce and explain the technology that is particularly relevant to e-business and e-commerce.
WHAT IS A NETWORK?
In IT, a network is a series of points or nodes interconnected by commun- ication paths. In a network, a node is a connection point for transmitting data, where it either recognises and processes transmissions or it forwards them to other nodes. Networks can interconnect with other networks to form large global networks.
Mainframes
An industry term for large computers. Mainframes are mainly used for handling very large amounts of data or many complicated processes, typically for the commercial applications of very large businesses, scientific or military applications or other large-scale computing purposes. The main advantage of mainframes is their reliability. The chief difference between a supercomputer and a mainframe is that a mainframe uses its power to execute many programs simultaneously, but supercomputers can execute a single program faster.
CASE STUDY Historically, mainframes used to occupy several rooms full of equipment. Some of the
first mainframes were the UNIVAC (Universal Automatic Computer) and the Electronic Numerical Integrator and Computer (ENIAC), illustrated in Figures 2.1 and 2.2. They were inflexible and costly machines often requiring special climate-controlled rooms
Figure 2.1 The UNIVAC (Universal Automatic Computer)
Figure 2.2 The ENIAC – the first digital computer Source: http://icarus.brainerd.net/ ~ kuck/history/mainfram/html
and were not easy to use. The operating system on a mainframe was cryptic, requiring a specialized skill set, and it was difficult for ordinary users to get information from the computer. Today, this is no longer the case. Mainframes, although still relatively expensive, can occupy the size of a laptop with relatively easy to use operating systems.
Midrange computers
These are medium-sized computers that are less expensive and smaller than mainframes, but are capable of supporting the processing needs of smaller organisations or managing networks. These include mini- computers and servers. In the past decade, the distinction between large minicomputers8 and small mainframes has blurred. But, in general, a minicomputer is a multiprocessing system capable of supporting between 4 and 200 users simultaneously.
A server is a computer or device on a network that manages network resources and provides software and other resources (such as sharing files, printers, software applications, database facilities, e-mail) to other com- puters over a network. Sometimes, servers are dedicated, meaning that they perform no other tasks besides their server tasks. For example, a file server is a computer and storage device dedicated to storing files. Any user on the network can store files on the server. A print server is a computer that man- ages one or more printers, and a network server is a computer that manages network traffic. A database server is a computer system that processes data- base queries.
Micro-computers
These are even less expensive than mid-ranged computers and vary widely in terms of processing power and price. Micro-computers include work- stations (which are supposed to have more processing power and are part of a network) and personal computers (PCs) (which are supposed to be largely for home users). However, in reality, there is little distinction between workstations and PCs because of the ease with which PCs can be configured. The principal characteristic is that they are single-user systems but it is common to link them together to form a network.
Historically, a mainframe was associated with centralised rather than distributed computing. Today, with the advent of e-commerce, improved
CASE STUDY Distributed computing case study
BASF, based in Germany, is one of the world’s leading chemical companies whose chemicals can be found in everything from snowboards, textiles and shoes, to cars, building materials and carpets. It has a large polymer physics department which studies problems in chemistry – two teams are devoted to molecular modelling and quantum physics. One of the key areas of study is in accelerated chemical reactions by catalysts – a task that requires highly complex and computationally intensive numerical simulations that can take days to run. Each team uses different cluster and departmental computer systems for their applications depending on the degree of criticality. BASF found that too much of their researchers’ time was being taken up with manually scheduling and processing tasks – for example researchers had to meet face-to-face with colleagues to select appropriate computers to schedule their jobs for submission. They also had to manually copy and retrieve files to and from the different machines. BASF did not want to spend money on hardware since they already had adequate resources, including the 300 office PCs and cluster of 10PCs with 2 processors each, but felt these were not being used as effectively as they could be.
The solution was distributed computing software that views the different comput- ing platforms as one system and automatically selects the strategy for processing the required tasks. The software reads the actual load of the different host computers, defines the resource requirements and the number of processors needed, and the appropriate architecture for the job. It then decides the optimal computer for the job, places it in the queue and transmits it to the existing machine when it is available. When different hosts are available, the distributed computing software sends the job to the system with a free load. Files are now automatically copied from the workstation to the computing engine and the results are returned to the users’ workstations without the need of manual intervention. BASF estimates that distributed computing has saved 20 per cent of employee time for scientific research work and processor utilisation has grown from 70 per cent to 95 per cent. They also estimate that they can now process ten times more structure because of the reduced demand for interactive work and a more robust, faster and automated workflow.
Source: BASF (www.basf.com)
WHAT ARE THE BENEFITS OF NETWORKS?
There are a number of benefits that can be achieved by a computer net- work. Different types of network deliver different benefits; however, in general the following benefits are common to all networks:
● Facilitating resource sharing – where all programs, data and equipment are available to anyone on the network without regard to the physical location of the resource and user.
● Providing reliability – by having back-up resources. For example, all files can be replicated and so there may be more than one copy of the same file; if a computer or printer is unavailable then another on the network can be used instead.
● Cost effectiveness– a small computer has a much better price/perform- ance ratio than a large one. Mainframes are 10 times faster than a microprocessor but 1000 times more expensive and cumbersome; now a single file server machine can be used to service a number of personal computers on a network. Also, using networks is cheaper than one computer directly contacting another.
● Provides a powerful communication medium among geographically separated people – exchange of text, graphics, video, audio and real time inter- action can take place easily across networks.
WHY ARE THERE DIFFERENT KINDS OF NETWORKS?
A network can be characterised by a number of different features, which describe its architecture and the kinds of facilities it enables. It is useful for non-technical managers to understand the different categories of networks and whether the functionality of those networks meets the organisation’s business criteria. Some of the different network characteristics are described below:
1 Whether it carries voice, data or both kinds of signals and thus the potential of using data networks for telephony purposes.
2 The nature of its connections9– dial-up,10 dedicated,11or virtual connec- tions.12 This has implications for the organisation’s security, network scalability and cost structure.
3 The types of physical links – for example, optical fibre13 is faster, lighter and more durable but is expensive and difficult to install; coaxial cable14 is faster than copper wire with reduced interference from external
‘noise’; unshielded twisted pair15 is less expensive but with more inter- ference. Physical links have cost, performance and ‘future-proofing’
implications for the organisation.
4 Geographical distance– there are four major distinctions of networks by geographic distance (summarised in Figure 2.3):
● A local area network (LAN) is a group of computers and associated devices that share a common communications line and typically share the resources of a single processor or server within a small geographic area (for example, within an office building). A local area network may serve as few as two or as many as thousands of users.
● A metropolitan area network (MAN) is a network that interconnects users with computer resources in a geographic area or region larger than that covered by a large local area network but smaller than the area covered by a wide area network. The term is applied to the interconnection of networks in a city into a single larger network (which may then also offer efficient connection to a wide area network). It is also used to mean the interconnection of several local area networks by bridging them with backbone lines sometimes referred to as a campus network. Large universities also use the term to describe their networks.
● A wide area network (WAN)is a geographically dispersed telecommu- nications network, the term distinguishing a broader telecommuni- cations structure from a local area network. A wide area network may be privately owned or rented, but the term usually connotes the inclusion of public (shared user) networks.
● The Internetis a network of networks that geographically covers the whole globe.
5 Topology – In the context of communication networks, a topology describes pictorially the configuration or arrangement of a (usually conceptual) network, including its nodes and connecting lines. The topology of a network illustrates the way data is transmitted and outlines the important nodes in the network. Common topologies include:
Figure 2.3 Classification of networks by geographical distance
● A bus networkor circuit arrangement where all devices (for example printers, computers, terminals) are attached to a central cable directly and all signals pass through each of the devices in both directions (illustrated in Figure 2.4). Each device has a unique identity and can recognise those signals intended for it. Only devices addressed by the signals pay attention to them; the others discard the signals. One of the main advantages is that since there is no host computer to control the network, if one of the nodes in the network fails, none of the other components will be affected. The main disadvantage is that the bus channel can only handle one message at a time, so performance can degrade if there is a high volume of network traffic. The bus network is most predominantly used in local area networks.
● A star network consists of a backbone (main circuit) to which a number of outgoing lines can be attached, each providing one or more connection ports for devices to be attached. All devices (prin- ters, computers, terminals, etc.) on the network are connected to a central hub where data comes together and is then forwarded to the necessary device (as illustrated in Figure 2.5). The main advantage of this topology is that it is more efficient because traffic is centrally controlled and applications can be processed centrally or locally.
One of the disadvantages is that all communication between points in the network must pass through the central hub or host computer.
Because this is the traffic controller for all other devices on the Figure 2.4 Bus network topology
network, the network will cease to function if the hub stops work- ing. This is the kind of topology common to Internet access providers.
● A ring networkis where each device is attached along the same signal path to two other devices, where the connecting wire or cable is in the shape of a ring or closed loop (as illustrated in Figure 2.6). Each device in the ring has a unique address. Information flows in one direction, and a controlling device intercepts and manages the flow to and from the ring. The advantage of this is that each computer operates independently, so that if one fails, communication through the network is not interrupted. The ring network is most predom- inantly used in local area networks.
6 Communication model – Networks can be broadly classified as using either a client/server or peer-to-peer model.
● The client/server model(illustrated in Figure 2.7) has become one of the central ideas of network computing. It describes the relationship between two computer programs in which one program, the client, Figure 2.5 Star network topology
makes a service request from another program, the server (sometimes called a daemon, which fulfils the request. The client is the user interface to request or initiate a function and is normally a desktop computer but can also be a laptop, Personal Digital Assistant or mobile-Internet phone. The user generally only interacts with the client application to input or retrieve data. The server provides the client with services. The server can be a mainframe but is usually a specialised server that can store and process data while at the same time performing a range of functions not visible to the users, such as managing network activities. Most business applications use the client/server model.
Relative to the Internet, a Web browser (such as Microsoft Explorer or Netscape Navigator) is an example of a client program that requests services (access to Web pages or files) from a Web server on the Internet. Checking e-mail using an e-mail programme uses a client/server model. Computer transactions using the client/server model are very common. For example, to check your bank account from your computer, a Web browser (client) on your computer forwards your request to a server program at the bank. That program may in turn forward the request to its own client program that sends a request to a database server at another bank computer to retrieve Figure 2.6 Ring network topology
your account balance. The balance is returned back to the bank data client, which in turn serves it back to the client in your personal computer, which displays the information for you.
● Peer-to-peer16 is where each party in the network has the same capabilities and any party can initiate a communication session. The Internet P-to-P communication model has been highlighted by the cases of Napster and Gnutella, providers of P-to-P networking soft- ware. A group of computer users with the same networking program can use the Internet to access and exchange files directly from one another’s hard drive or through a mediating server. Napster was the leading on-line P-to-P software provider, enabling users to swap music files. It suffered a barrage of legal attacks from the music industry who accused it of copyright infringement by providing the software that enabled copyrighted music to be swapped freely.
Litigation is still ongoing and the majority of legitimate file swap- ping sites no longer allow the free exchange of copyrighted music.
However, corporations are now looking at the advantages of using P-to-P as a way for employees to share files without the expense involved in maintaining a centralised server and as a way for businesses to exchange information with each other directly.
Figure 2.7 Client/server computing model