Describe the order in which a message passes from one piece of hardware to the next when a home user in the United Kingdom sends an e-mail via the Internet to someone in a large corporation in the United States. You should refer to the following terms:
(a) mail server;
(b) client PC;
(c) modem;
(d) hub;
(a) network cable;
(b) network card;
(c) gateway server (telecommunications processor);
(d) router.
Treat the Internet transmission as a single stage.
The order in which messages are passed is from:
(b) client PC to (c) modem to…
phone line connected to an Internet service provider (ISP) which will be connected to the Internet. The ISP will also contain many of the other devices referred to below that will be present in the corporation in the United States, in particular, it will probably pass through (a) a mail server, (g) a gateway server and (h) a router. The Internet links will occur by the message being sent by many routers and over different media.
The Internet will be connected to a server in the corporation known as the
(g) gateway server that will be connected to the Internet and that will act as a firewall between the corporation and the Internet beyond. It may be connected to the mail server by
(h) router (optional) and (e) network cable linked to (f) network card in the
(a) mail server – this will be a separate server specifically used to process e-mail
(h) router – used to route the mail message in the organisation along the correct network
(e) network cable
(d) hub – this may be used to link a segment of the network directly to a PC (e) network cable, sometimes known as patch cable connected to
(f) network card in the (b) client PC.
Activity 5.2
To provide an example of the services provided by ‘cybermediaries’ and explore their viability as businesses.
• Visit the Kelkoo web site (www.kelkoo.co.uk), shown in Figure 5.6, and search for this book, a CD or anything else you fancy. Explain the service that is being offered to customers.
• Write down the different revenue opportunities for this site (some may be evident from the site, but others may not; write down your ideas also).
• Given that there are other competing sites in this intermediary category such as Shopsmart (www.shopsmart.com), assess the future of this online business using press releases and comments from other sites such as Moreover (www.moreover.com).
• Kelkoo provides a price-comparison service. The desired product is typed in and a database is searched for suppliers who have this product. Different prices and other extras such as delivery and guarantees are then listed. Typically the consumer will pick the supplier with the lower price.
• The main revenue will come from commission for products bought. Kelkoo will be an affiliate of each of the e-tailers it is linked to. Payment options for affiliates typically include the following:
(a) A small percentage of the product purchase price from the e-tailer from which the product is purchased (the normal affiliate model).
(b) Payment for a lead or enquiry that does not necessarily result in sale. This is more favourable to the affiliate and this is the arrangement negotiated by Kelkoo because of its strength in comparison to e-retailers.
Other revenue models include general banner advertising on the site, together with advertisements from the manufacturers of products (e.g. book publishers) or from the e-tailers (a small banner ad may be placed by the e-tailer to establish its credibility).
• A problem with the business model of such intermediaries is that only a small percentage is paid by the e-tailer to the intermediaries, so many transactions must occur. This is also a problem for the similar service from Lastminute.com (www.lastminute.com). It is forecast that the next stage will be a shake-out as many of the cybermediaries and B2B marketplaces fail, leaving room for a handful of key players in each sector. As a consequence, intermediaries such as Kelkoo are spending a large proportion of their funding capital on advertising to build their market share.
Case Studies
Case Study 5.1: Finders keepers
1. Discuss the benefits and limitations of RFID technology.
Benefits:
• Decreasing cost
• Requires no line of sight between tag and reader.
• Allows tracking and monitoring of virtually everything that moves.
• Provides real-time information on movement of stock in supply chain permitting quick response.
Disadvantages:
• Costly compared to bar codes.
• Limited range between tag and reader – a few metres.
Case Study 5.2: The all-in-one thingumajig
1. What reasons can you give for the lack of success of converged technological devices?
• Paying for facilities not needed
• Lack of focus in marketing benefits of device
• Best-in-class technology tends to be in specialised devices, not in converged technology
• Cost of converged technology makes price too high for many potential customers
• Unlikely to replace standalone devices so expensive as additional device
Exercises (pp. 225–227)
Self-assessment exercises
1. Specify the components required for a client/server-based LAN for a company of 10 people.
The answer should start by identifying the need for a single, more powerful server computer to share information between the staff. One server is sufficient due to the number of staff in this instance. However, if there were more than 100 people, then the use of departmental or
workgroup servers would be appropriate. The server could be connected directly to the Ethernet network using a hub as the telecom processor.
Client PCs will be needed by the number of staff who require access to a PC. The PCs will be connected to the network by a network interface card. Modems are not appropriate.
A bus arrangement ethernet is the most suitable for this number of staff given its low cost. A token-ring network might be required for a larger company.
2. Distinguish between a local-area network (LAN) and a wide-area network (WAN).
The answer should stress the difference in scale, with the LAN used to connect computers within an organisation based on a single site and the WAN used to connect people on multiple sites. Note that the WAN can be used to connect users who are in different organisations such as suppliers and distributors of products.
3. What are the main business benefits delivered by a local-area computer network?
• Information sharing and collaboration between staff
• Cost reduction through sharing of peripherals, such as printers and tape storage, and through sharing of information which will result in lower consumable costs such as printer toner and paper
• A capability for new techniques of communication and control that are available through e-mail
Students could use the ‘6Cs’ framework (Chapter 8) to indicate benefits such as cost reduction, new capability, control by managers and improved communications.
4. What are the main components of a telecommunications system?
The main components are the client access device and the remote device where the information is stored and transmitted (the server). In between the origin and destination of communications are the telecommunications processors such as routers which are used to select the best pathway for information and the physical media used to transmit information (the cables and other media such as satellite).
5. What is the purpose of a network operating system?
The NOS is systems software that is used to manage the network. It controls the following:
• Security through the use of user names and passwords
• Sharing of information between users in different locations
• Access to information according to the permission granted to different users
• Communications and passing of data between different components on the network
• Sharing of devices, enabling, for example, the backup to tape of data on the server, or printer sharing
6. What is the difference between the Internet and the World Wide Web?
The Internet refers to the physical network that links computers across the globe. It consists of the infrastructure of network servers and communication links between them that are used to hold and transport information between the client PCs and web servers.
The World Wide Web is a method for storing (web servers), transmitting (the HTTP protocol) and displaying (through web browsers) information across the Internet. It is effectively the publishing mechanism.
Using the TV analogy, the Internet is the network for transmitting data globally, while the Web is the method of delivering the content (channels).
7. Describe the two main functions of an Internet service provider (ISP). How do they differ from applications service providers?
Internet service provider (ISP) – definition:
A provider provides home or business users a connection to access the Internet (1). They can also host web-based applications (2).
Application server – definition:
An application server provides a business application on a server remote from the user. ISPs simply offer access and hosting; they do not typically provide access to specific business functions such as finance services, which are provided by software providers such as Microsoft and Oracle (although this may change as ISPs sell a wider range of software services).
8. Distinguish between intranets, extranets and the Internet.
In summary, they refer to different levels of access – the Internet is public, the intranet is restricted to organisations and employees, while an extranet is restricted to access beyond the company.
Intranet – definition:
It is a private network within a single company using Internet standards to enable employees to share information using e-mail and web publishing.
Extranet – definition:
It is formed by extending the intranet beyond a company to customers, suppliers and collaborators.
9. Describe the standards involved when a web page is served from a web server to a user’s web browser.
Request page and deliver page (HTTP), transfer request and information (TCP/IP) and render page in the browser (HTML).
TCP/IP – definition:
The Transmission Control Protocol is a transport layer protocol that moves data between applications. The Internet protocol is a network layer protocol that moves data between host computers.
HTTP (Hypertext transfer protocol) – definition:
HTTP is a standard that defines the way information is transmitted across the Internet between web browsers and web servers.
HTML (Hypertext Markup Language) – definition:
HTML is a standard format used to define the text and layout of web pages. HTML files usually have the extension .HTML or .HTM.
Discussion questions
1. Do you think that the introduction of client/server system has been worthwhile to businesses?
This question is a straight analysis of the business benefits compared to the disadvantages of client/server system. It is a specific instance of a general issue facing businesses with the introduction of any new technology. Client/server system can be compared to a previous situation in a business where the PCs are not networked or more likely, a mainframe is used with character-based dumb terminals.
The key benefits of client/server system are as follows:
• The cost-reduction available through downsizing to lower-cost hardware and software
• Improved flexibility for the end users to deploy specialised applications and to write their own applications using tools such as MS Excel or Access
• Improved ease of use on the client side since traditional applications tend to be character-based rather than using a WIMP interface (Chapter 4)
The main disadvantages are as follows:
• The cost-reduction argument is not clear. The experience of implementing client/server system is that although the purchase price of hardware and software may be lower, the lifetime or total cost of ownership (TCO) may be higher. Much analysis of TCO has been conducted by the Gartner Group (www.gartner.com) and is briefly referred to in Chapter 16. The high TCO of client/server systems arises from the cost of supporting them; since it is easy to modify the configuration, it is also possible to stop applications working. This problem is compounded by the range of networking drivers and software applications that are available from different vendors. In a traditional mainframe environment, the software would typically be sourced from a smaller number of vendors.
• The stability or reliability of client/server system is questionable. There are many examples of client/server system failures mentioned in the UK trade papers such as www.computerweekly.co.uk and www.computingnet.co.uk. A recent example is that of the roll-out of a UK-wide system for the National Westminster bank that is based on Windows NT. This rollout has experienced technical difficulties resulting from software incompatibilities.
• The control and administration of traditional mainframe systems tend to be easier since they are more centralised, with less opportunity for the end user to configure the software. This is similar to the TCO argument.
• The security of client/server systems may be less robust than mainframe systems.
C H A P T E R 6