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Introduction to the Internet An NSS Group White Paper Table of Contents IntroductionWhat is the Internet? A Brief History Lesson Uses of the Internet Electronic Mail World Wide Web (WWW) File Transfer Protocol (FTP) Gopher Newsgroups Internet Relay Chat (IRC) Web Commerce How To Connect To the Internet Personal Connection Network Connection Remote Access Server (RAS) Bridge/router Summary Few people can have missed all the talk about the Information Superhighway and the Word Wide Web over the last twelve months. The whole world - and not just the computer world - seems to have gone Internet crazy. From home hobbyist to senior IT director, huge interest has been shown in this world-wide internetworking service. The key to its popularity is the fact that the end user need know nothing about how this global network is actually constructed in order to make effective use of its facilities. As long as you know the "address" of the item you are searching for (analogous to knowing the postal address or telephone number of a company to contact them outside of "cyberspace") you can send messages or access their on-line services. Estimates of the growth in the number of Internet connections range from a conservative 10 per cent to a staggering 4000 per cent per month, and there are now real commercial benefits to be gained from establishing an Internet connection. Though it is not necessary to know how the Internet works in order to get the most from it, it is always nice to be able to wow your friends at parties with your knowledge of the latest "cyber-culture". In simple terms, the Internet is actually a collection of computers situated all over the world, connected together by telephone lines and other high-speed communications links. All of these computers talk to each other using a unique language known as a "protocol", which in this case is called TCP/IP. From a PC in Bedford, England, you can access information from a computer in Sydney, Australia all for the price of a local telephone call. As with the telephone system, you don’t actually need to know the mechanics of how the thing works in order to make a call - all you need is the telephone number of the party you wish to contact. So it is with the Internet - all you need is the "address" of the computer you wish to access. Once you start to wander around the Internet, you can find information on virtually any topic you would care to mention. You can obtain information from universities, charities, entertainment organisations, government agencies, political parties, and even private individuals. This information can simply be browsed in place, or can be downloaded to your own computer to peruse at your leisure. A Brief History LessonWhat is commonly referred to as the "Internet" today, has evolved from technology developed in the US Defence Department - the Defence Advanced Research Project Agency (or DARPA) to be precise - in the mid-1970’s. A network called ARPANET was built to connect military organisations with defence contractors and university researchers providing a rapid means of communication and the ability to share costly central resources such as supercomputers. ARPANET gradually evolved into what we now know as the Internet, and in the early 1980’s commercial organisations began to use the infrastructure in earnest. Responsibility for, and control of, the Internet passed form the military to the commercial sector, and what was once the domain of defence contractors and researchers has become commonplace in many homes and businesses. The Internet is now a true global information network - comprising thousands of smaller computer networks in a wide variety of organisations and businesses - linking millions of users and networks in almost every country of the world. Today there are over 3 million computers attached to the Internet, with over 25 million users in 84 countries accessing it 24 hours a day. The Internet is one medium where the only limit is the imagination of the end user. The following services are available : Also known as e-mail, this is possibly the first application which springs to the mind of the average person when the Internet is mentioned. When you first connect to the Internet you are given a unique identifier known as your e-mail address - something along the lines of bwalder@ NSS.brand.co.uk. This is directly analogous to your postal address, and anyone who knows this can send messages to you over the Internet. Where the analogy breaks down, however, is the fact that your e-mail message will take only minutes - sometimes mere seconds - to reach its destination, whether the recipient is located next door or on the other side of the world. Some e-mail software will also allow you to "attach" any number of other documents - such as spreadsheets or graphics files - to your -email message when you send it, thus making the Internet a good all-round medium for file transfer and message delivery. Right up there alongside e-mail in the popularity stakes - particularly because of its appeal to the home and casual user community - is the World Wide Web. Sitting on top of the potentially user-hostile network of UNIX, NT, OS/2 and NetWare servers which makes up the Internet, the WWW is the "friendly face" of computing. Using a simple, highly graphical interface, the WWW allows users to browse in an ad hoc fashion around the Internet, with every Web server a potential mine of information. Every single computer on the Internet has a unique four-segment address which looks something like 194.123.43.55. Remembering more than one or two of these would be quite difficult, so each set of numbers is translated into something called a "domain name" by another set of computers on the Internet which provide a Domain Name Service (DNS). This allows you to use a more recognisable name such as NSS.brand.co.uk (The NSS Group domain name) rather than a string of numbers. On the Web, this domain name becomes the Uniform Resource Locator, or URL for short, which allows you to access a Web server directly. The URL is that weird bunch of characters you are now seeing on television commercials, business cards and company letterheads, taking the form of http://www.NSS.brand.co.uk, or simply www.NSS.brand.co.uk. Of course, you will also need some software on your PC in order to access the World Wide Web. Such software - known as a "Web browser" is freely available, with the most common being Netscape Navigator, Mosaic and Microsoft Internet Explorer. Once the user has the Web address - or URL - of a company, the browser software will take them straight there. No matter if the actual Web server is based on the other side of the world, and the data has to pass through several routers on its way from server to client - such complexity is hidden from the user completely. Transparent "hypertext" links between Web pages on different servers can route you around the globe without you being aware of it. One minute you can be looking at the catalogue of a major book publisher, and the next you can find yourself in a discussion about rain forest depletion in an American newspaper - it really is that simple. This provides a simple way for users to transfer files to and from remote computers - known as FTP servers - once again without having to know anything about the physical network layout nor where the FTP server is located. Data files are stored on the FTP server in a DOS-like directory structure, allowing point-and-click selection of the required file. This is similar to FTP, in that it is used for file transfer, but provides a more user-friendly way of finding information. On a Gopher server, a menu-based system makes navigation and general usage much easier than FTP, and full descriptions of files and directories are provided as opposed to terse DOS-like file names. WAIS (Wide Area Information Service) is virtually identical to Gopher in terms of functionality, and this is the protocol on which the US Government has standardised for its enormous collection of data. These are on-line discussion groups where Internet users can both post and read opinions about various topics. They can be thought of as electronic versions of the familiar notice board found in many large stores, schools, clubs, etc. Unfortunately, Internet news has often been likened to "CB radio on computer" due to the large amount of banal "chatter", even though there are many serious - and very useful - technical and general information newsgroups to be found. IRC provides a means of carrying out a real-time electronic conversation over the Internet with another person or group of people. Instead of talking face-to-face, however, you use your computer screen and keyboard, typing the words as you go and seeing the replies appear on your screen. The Internet is nothing if not an equal opportunity environment, and any company can set up a Web server (or rent space on someone else’s) in order to publish information about their own company or services. As well as simply giving out information, a well-designed Web site can collect information from its "visitors" - perhaps customer feedback or suggestions - and even take orders for products. Many businesses are setting up electronic "shop fronts" on the Internet in anticipation of secure payment mechanisms becoming widely available during 1996. How to Connect to the Internet At the most basic level, all that is required to connect to the Internet is a modem attached to your PC and a connection to an Internet Service Provider (ISP). More and more ISP’s are springing up every day, further illustrating the increasing popularity of the Internet in general. Some established on-line services - such as CompuServe and America Online - have also begun to provide Internet access alongside their normal services. What the ISP provides - usually for a monthly or hourly connection fee - is a user account (which becomes your e-mail address) and password, together with the ability to dial into a local Point Of Presence (POP). These POP’s are nothing more than remote sites for the ISP which provide a link to the Internet for the cost of a local call to the end user. Microsoft has done an enormous amount to increase the number of connections to the Internet by including all the appropriate client software in the shipping version of its desktop operating systems such as Windows 95 and Windows NT Workstation. Straight out of the box, the user is able to set up and configure an Internet connection, and within minutes he or she can be "surfing the net". This desire to make surfers out of us all is not entirely altruistic, however, since also included is the ability to connect directly to the Microsoft Network (MSN). Despite the huge choice of ISP’s out there, a significant number of new Windows users will undoubtedly opt for Microsoft as their Service Provider, simply because it is a "one stop" shopping exercise. Whilst the most straightforward means of connection is undoubtedly the direct modem connection, it is not necessarily the most cost-effective. Because an increasing number of companies are recognising the Internet as an ideal source of information and free technical support - as well as the perfect medium for advertising - the requirement for an Internet connection to every desk is becoming a reality. However, the cost of a modem and a telephone connection for all employees in even a small company can make the exercise cost prohibitive. And it certainly is not the best use of resources which are already available. We are talking, of course, about the Local Area Network (LAN). Most LANs were installed in the first place to leverage investment in hardware and software by allowing a number of users to share scarce - and often expensive - central resources such as database servers, printers, scanners, and communications links. An added advantage of this method of Internet connectivity is that by using an appropriate e-mail gateway product, Internet e-mail can be transmitted and received from the client desktop using the existing corporate e-mail system. This creates a world-wide "virtual private global network" at a fraction of the cost of investing in truly private, dedicated leased lines. There are two approaches to this : This is a box which sits directly on the corporate LAN, and to which are connected a number of standard modems. From any workstation on the network, the user can dial out from their PC just as if they had a modem attached locally. As the client attempts to dial out, the Access Server intercepts the call, allocates a modem, and from then on the call can proceed as normal. If all the modems are in use when a user attempts to make a call, that user can be placed in a queue until a modem becomes free. This "pooling and queuing" mechanism allows relatively few modems and communications lines to be effectively shared amongst a large number of users. Another advantage of the RAS is the ability of remote clients - perhaps situated at home or in remote offices - to dial into the corporate network and provide access to all the central resources just as if their laptop were connected locally to the LAN. With the availability of V.Fast modems, speeds of anywhere between 28.8Kbps and 230.4Kbps are theoretically possible, so a basic asynchronous dial-up connection across ordinary phone lines needn't be slow. Bear in mind that many communications servers only support up to 115.2Kbps however. Also, the very slow call set-up time - necessary for each modem to establish the standards supported by the other - makes a modem far from ideal for providing supposedly transparent connections either to the Internet or between remote networks of any kind. An increasingly popular option, therefore, is to go for an ISDN-based remote access device. These have been appearing over the past three years in the form of PC-based or standalone bridge/routers. Today’s access router or brouter supports everything from asynchronous modem dial-up to X.25, leased line, ISDN, frame relay and increasingly SMDS (Switched Multimegabit Data Services) and ATM (Asynchronous Transfer Mode). However, because the data connection is rarely required to be up all day - it may indeed be active for only a couple of seconds at a time to transfer e-mail messages - ISDN is often the preferred solution for Internet connectivity. Basic Rate ISDN (BRI) actually comprises two 64Kbps (or 56Kbps) lines (the "B" - or "Bearer" - channels) for voice, image and data communications, plus a separate 16k "D" - or "Data" - channel. Apart from the obvious improvement in bandwidth over standard modem connections, ISDN also offers extremely fast call set-up times of just a second or two (and often less). This is a great boon for e-mail transfer, when the amount of time to set up a call using modems can be far greater than the actual time needed to transfer the data. The 128Kbps from the combined B-channels is not the end of the story however. With many of the products available it is possible to aggregate multiple ISDN lines, so achieving bandwidths of 640Kbps and more. However, from a cost point of view, you need to be careful when establishing whether Basic Rate (2x64Kbps connections) or Primary Rate (30x64Kbps connections) ISDN is what you need. Currently the cross-over point between the two occurs at about five Basic Rate lines. So once above this requirement it is more cost effective to install a Primary Rate service whether you need all 30 channels or not. Many PTO’s now provide primary rate ISDN in smaller "packs" of 6, 8, 10, 15 or 25 channels at a time, and will often allow you to increase your bandwidth in single 64Kbps channel increments. Hopefully this White Paper has given you a basic understanding of what the Internet is and how you can connect to it and use it. |
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