Introduction To The Internet

     Session 1

Connecting Internet applications Addresses 

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What is the Internet? 

The Internet is a different experience! It is difficult at times to find analogies, and jargon becomes almost inevitable. 

The Internet is a Network of millions of computers, each of which can send and receive data to and from each other. Individual computers or small networks connect to "Internet Service Providers" (ISPs) via a phone line or broadband connection. ISPs make connections to Worldwide communications companies over very high speed lines. The computers send or receive packets of data each other with a unique delivery address. "Protocols" ensure that packets are delivered error free to the right place by obtaining an appropriate response from the receiving computer, and re-sending if necessary. 

The Internet is not hierarchical. It has no centre, no top, no bottom. "All packets are created equal". It is fault or failure tolerant (part of the original military specification) because packets of data can be sent different ways from point A to point B. It is owned by nobody, or it is owned by everybody. There may be over 50 million computers used by 200 million people, but no one knows accurately. Costs are met by clients paying for local phone calls or broadband use, and paying ISPs for their hardware and operation. ISPs pay the major computer up the line, who in turn pay the major communications trunk carriers. Paid advertising appears on many commercial supplier's pages. The actual information on the net is usually free. Will this last? 

There seems to be a view of industry and other organisations that they must be on the Net, but they're not sure why. They feel instinctively that if they are not they may be left behind, and miss out somehow.


To be able to connect to the Internet, you need a computer system, a reasonably good phone line or broadband circuit (can be via phone line or 'cable' which also normally delivers TV as well). Also you will need an account with an ISP, software (programs), and some knowledge on configuring and using the system. Some systems connect via TV cable modems, satellites, radio links, etc. 

Once connected you can select applications (programs) to carry out useful activities. Many ISPs supply a floppy disk or CD to configure your computer for their service. Often the configuration is almost automatic. But if not - manual configuration procedures are provided in these notes.


Computer: The computer requirements are not very demanding. Any machine made in the last 3 or 4 years will be O.K.. However, in the PC world hardware capable of running Windows 98 or XP is very desirable. Of course it's like everything else in computing - bigger, faster, and more modern usually creates a better experience.

There are two particular parts of the computer which you need for Internet. For a dial-up connection using an external modem, a spare serial communications (COM) port. Normally you have two, with one (COM1) in older systems often connected to the mouse. The Modem (see below) will normally connect between COM2 and the telephone line. How to connect up the modem and configure the computer software to use it will normally be covered in the manufacturer's handbook. Many current systems come with "internal" modems (normally configured on COM3) - if so, you will not need to worry about external COM ports. Just a connection to your phone system. Broadband connections use special modems (ADSL) to connect to your phone line, or a special cable to your cable system set top box. For Broadband - the connection to the Modem or Set top box normally goes via an internal Network Interface Card (NIC).

Modem: The modem (both dial-up and broadband) is the device which takes the computer's data and converts it into a form suitable for the phone line. External modems have a cable with 25 (or 9) pin connectors to/from the computer, and a thinner cable to connect to/from a telephone socket. The modem will usually have a socket for a normal phone handset if you wish to connect one (and this can be useful). Power for external modems will usually be from an external plug pack power unit - this being mainly for safety reasons, by making sure that 230v does not appear inside the modem box and then possibly onto the phone line 

An alternative to the stand-alone modem is the internal modem. This simply plugs into a spare slot inside the computer, and has a phone line socket for connection to the outside world. Internal modems are generally cheaper than external ones, with much less cabling and so should be popular, but they are not. External modems have a bank of lights which can be quite helpful when troubleshooting. And almost everybody (often including experienced computer people) has problems when attempting to configure new hardware inside a computer. So generally the advantages of external modems outweigh the disadvantages. Also it is easy to test an external modem on someone else's PC (and phone line) if you have problems on your own system.

Serial Port and Communications: It is not necessary to understand the details of serial communications, but an understanding of the lights on an external modem is very desirable, if only to be able to describe to someone else what is happening. So here goes: 

Note: Not all modems include all the following indicators. 


Clear To Send

The modem is telling the computer it is ready for data


Data Terminal Ready

The computer is Ready and Configured


Request To Send

The computer is ready to send data


Off Hook

The modem has connected itself to the phone line


Data Carrier Detect

A successful connection has been made to the remote modem


Error Correction

- is active


Data Compression

- is active


Transmit Data

Data is leaving - outgoing


Receive Data

Data is arriving - incoming


Auto Answer

Used for receiving Fax. Flashes with incoming ring

 Phone Line: A phone line to a modern exchange should allow a 56 Kbs modem to perform at speeds between 40 and 50 Kbs (thousands of bits per second). This is pushing the phone line beyond the specification for good audio communications, and you might well have a line which is quite acceptable for normal phone connection but gives a poor computer data connection. You may then have difficulties in getting Telstra to admit that improvement is warranted, let alone practical. In country areas of Australia, 9.6 Kbs is often regarded as a good connection. Dial-up modems adjust their speed to the maximum that the phone line can handle.

Telstra has other problems in dealing with modem (or fax) data. All their systems are modelled on speech spectrums where sound is not continuous, and when a number of lines are combined, the total load is less than the sum. Modems upset that tradition. On the other hand, the Internet is generating a large demand for wide band data lines within Australia and internationally. It is suspected that Telstra has a love hate relationship with the Internet. 

Purists say that you should disconnect all other phones and other devices from your phone line when using your modem. Most users experience is that this is not necessary but if you are having problems it's certainly worth trying. Some old phones (e.g. Old Telstra Touchphone 200) and some cordless phone equipment can cause interference. You also may have to find ways of deterring others from picking up other phones in the house while you are connected. If you have the Telstra "call waiting" facility, this should definitely be deactivated whilst connected, as the "waiting" tones will disrupt modem data. In any case it is not practical to put a data call on hold while taking an ordinary call, even if you could hear the beep. To deactivate call waiting for one call (in most areas) in Windows 98, go to My Computer, Control panel, Telephony, Tick "to disable call waiting", and enter *44 into the box provided.

Broadband using Cable or phone line: ADSL (Asynchronous Digital Subscriber Line) uses a special modem connected between your phone line and your Computer Network Interface Card. It allows very fast computer access (between 256 Kbs and 2 Mbs - pay more for faster access). It cannot be used in all phone areas and speed is dependant on distance from the phone exchange. The phone can be used at the same time as the Internet. Cable Internet (provided by TransACT in Canberra) also allows very fast access and is totally independent of the phone line.

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Internet Service Providers

ISPs: The next link in the chain is the ISP. It is the organisation which provides the interface between you and the world-wide network of computers. 

Each ISP has a bank of modems (or digital receive lines) and this is where your system has to contact to establish a connection. When the two modems have negotiated a connection you then have to identify yourself to your ISP via a user name and password. NOTE: Some ISPs automate this process to be almost invisible to their customers. After that, a computer to computer connection needs to be established. When all this has occurred satisfactorily, the timing (charging) clock starts and you are free to use your application software such as Internet Explorer. Some people prefer to load applications before connecting.  Note: Many people use their Web Browser or their E-mail program to initiate the connection.

Costs: A modern computer suitable for Internet use would cost about $1,000 - $2,000, but usable second-hand ones could be $500 or less. Modems are currently about $60 - $250. ISPs all charge differently. They range from $9 per 5 hrs to $50 for 250Hrs per month. Most ISPs charge by the month and some add a $10-$25 start-up charge. Some have various free hours per day (or per week or per month) with the rest charged at various rates. These can also vary with the time of day, and with various "use it or lose it" rules. Additional charges per Megabyte downloaded (above a "threshold") are used by many ISPs. There are a few "Free" ISPs around these days - these support their operations by constant advertising (cannot be turned off) on your computer and collecting (and probably selling) user demographic data. Costs are steadily reducing with increased competition. Broadband ISPs (most ISPs can support both Broadband and Dial-up) generally do not charge by the hour and connections can be active for 24 Hrs/Day, but charge by the number of Download MBits per month. The definition of Download is for the ISP's computers to count every Bit that they deliver to you - this can be Emails, web pages, Music, on-line radio broadcasts, etc. Allowances vary between 100 Mb/month (about $15) to several thousand Mb (up to $100). Some ISPs will 'roll over' unused Mb from one month to the next - but most adopt a 'use it or loose it' policy.

The permutations are endless and it is very difficult to compare suppliers. The best buy will vary from person to person depending on how often, how long, and typical time of day of main use. In any case the quality of service delivery cannot easily be defined, assessed or compared.. One important parameter is the number of customers per modem, as a measure of whether you can expect an engaged signal or not when you dial in. Another is the bandwidth (divided by the number of customers or lines) between the ISP and the major entry point to the Net. Quality help desk support via a local call for at least 10 hours per business day is a most important consideration and is probably the primary cost driver. The "free" CDs from Australian PC User magazine sometimes include very complete listings of ISPs and some selection hints. Finally be wary of "100 hours free" offers, their Internet installations can be very difficult to remove from your system if you decide not to continue with the service.

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Most software to use the Internet is currently free - much of it is "given away" by ISPs or on CDs by computer magazines. Purists may prefer certain commercial or "shareware" programs, but generally the performance and features are similar to the "freeware". Windows 95 and above (98, ME, NT, 2000 or XP) currently include all you need to get started.

Connection - TCP/IP, PPP: Dedicated software is needed to establish the computer to computer (Your computer to ISP) connection, using a Protocol called TCP/IP (Transmission Control Protocol/Internet Protocol) and PPP (Point-to-Point Protocol). Windows 95 and above have inbuilt connection capability (but it has to be set up for each ISP).  Broadband uses various protocols and may need extra software to be installed.

WWW Browser: Usually Microsoft Internet Explorer (MSIE) or Netscape. This software allows you to enter an Internet address, display received pages in various ways, and save or print them.

E-Mail: E-Mail software allows you to compose messages on, or off-line (connected via your phone line, or not) and send messages to your ISP for on-forwarding anywhere in the world. It also allows you to receive messages addressed to you waiting at your ISP, and for displaying and storing them in many different ways.  E-mail software such a Netscape mail or Outlook Express may be included with the WWW browser, but there are many "stand alone" programs available, such as Eudora and Agent..

News: This software is similar to E-Mail and might be in the same package. It allows you to get the names of all the Newsgroups which your ISP handles (usually 25,000+), subscribe (no cost) to whichever ones you want. To receive and display messages, and to compose and send messages to newsgroups. Netscape includes news software, and Outlook Express semi-integrates Mail and News functions.

File Transfer: Commonly called "downloading or uploading". The transfer of files is relatively simple and the software to do it is readily available as shareware. The software makes all the relevant connections and displays the status during transfer. Again make sure you have the 16 bit or 32 bit version as needed by your system. Most modern WWW browsers incorporate FTP (File Transfer Protocol) capability

Connection Sequence 

Initial setup:
Windows 95 and above - the basic connection software required is built into the operating system, but it needs to be set-up unless your chosen ISP provides an automated Net access installation disk. Manual configuration steps are documented in many places on the net (Assuming you know someone with access!). Of course once you are on the net you hardly need it! Instructions are included here, and they are intended as a "stand alone" guide so include some redundant information included elsewhere in these course notes. Go here for the connection notes (use the browser back button when you have finished to return to these notes).

 Note: These connection instructions are oriented towards the Canberra PCUG (PC User's Group) Internet service, but can be used as a guide to check options for other ISPs.

Once the connection is configured, Windows will bring up a Connection box like the one on the left after you click on the ISPs desktop Icon, or you run a program that needs to connect to the Internet. Then a click on the connect button should have you connected - the process will take up to 30 seconds or so with a dial-up connection (You will normally hear the modems 'negotiating' a useable starting speed), or 1 to 10 seconds for a broadband connection - hopefully you will not hear too many noises when connecting to broadband....

Note: The 'connect box' shown is for a PCUG broadband connection where the full Email address is used as the User Name - also if the 'save user name and password box is ticked, the password will not be saved until a successful connection is achieved.

Once set-up, you should soon reach the stage where you can routinely connect to the network. You will need to go through a sequence each time you log in. 

Some users recommend that you load applications before connecting. This is not necessary, but does save a little bit of connect time. Also, you can run several applications simultaneously under Windows on the Internet. You can also run more than one copy of the same program simultaneously

Having loaded applications (normally for Email and web browsing), double-click on the ISPs desktop connect icon, and then on the Connect box. With Dial-up you will then hear the modem connect sequence take place - dial tone, dial, modem negotiation tones, and the modem Carrier Detect light will come on. Then a display will come up saying something like "Checking name and password" followed by "Connect at 43,666" or similar, and you will see a small icon appear in the 'system tray' area at the bottom right of your screen. The icon looks like 2 tiny computer screens which flash on and off. Actually one 'screen' of the icon indicates Transmit data (from you to the ISP) and the other receive data (from the ISP to you). The icon is very useful as it is a constant reminder that you are on-line and the ISPs $ clock is ticking. Broadband connection is very similar except it happens much faster and there are no modem noises. The 'two screen icon' also indicates an on-line broadband connection.

You can now run any or all of your Internet applications and enjoy the benefits of the Net....

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Internet Applications

The Internet comprises a number of functions, categories or applications. All of them can be happening at the same time in your computer. They have varying degrees of interaction 

World Wide Web (WWW) 

The World Wide Web is the system for accessing information on the Internet. Information is usually organised into "pages" - which can be any size - comprising a mixture of text and graphics, and occasionally audio and video. Each page on the Web has a unique identifying address called a URL (Uniform Resource Locator). Any piece of text (or image) can have the address of any other page associated with it. Such a link may be underlined and identified by a unique colour and is known as a hyperlink. Hyperlinks can also be identified by icons or different parts of a picture. If in doubt about identifying links, watch the mouse cursor - when it changes from a pointer to a hand with a pointing finger - you are over a link. Clicking on a hyperlink will connect you to the link's address and bring in the corresponding page's information. This is the major feature and strength of the World Wide Web as compared with other computer based information systems - it is NOT hierarchical, and it is possible to jump from any place to any others of millions of places by "pointing and clicking". 

A displayed page can be scrolled up and down (and left/right if necessary) using normal windows navigating techniques. Text can be copied and pasted in normal Windows manner. Pages can be printed, and stored as files. Graphics can make for an attractive display, but take much longer to download than text (and use more of your download allowance if you have that kind of account). 

The "Point and Click" User friendliness of WWW has contributed most to the explosive growth of the Internet.


Electronic mail allows you to send a message to anyone with access to the Internet anywhere in the world. The cost is negligible for casual users once you are connected. Messages can be prepared "off-line" and the actual time to send and receive messages is very small. Text based Email is a very small download size compared to graphics intensive Web pages. Actually, for members of the Canberra PC Users Group the cost is almost zero because "Limited" Access (for E-mail and News only) is free for members, except for the cost of the phone call.

Many types of attachments can be sent with an E-mail. For example a scanned image or a voice file, although care has to be taken not to include large audio or video files in a system which is actually designed for text messages. 

E-mails can include addresses of WWW pages which can be simply clicked in the message display - and that address will be displayed by your browser.

"Usenet" - News 

News is similar to E-mail in many ways in that text messages are sent and received. But in "News" a message is made available to all who "subscribe" to that group, so the message is effectively broadcast, rather than being sent to an individual. Much like a bulletin board.

File Transfer Protocol (FTP)

There are many occasions when you would like to receive a file from an Internet address. For example, just about all the software you would ever need to use the Internet is available on the net. Updates and patches to popular programs are there. Updates to Microsoft's Encarta Encyclopaedia can be downloaded.  Most files can be downloaded via your browser software, but stand alone file transfer software is also popular.


Everywhere on the Internet has an address. There are only two different types - for E-mail and for the rest 

Email  All E-mail addresses are of the form  who@where 


"who" is an identifiable name, alphanumeric characters mainly, usually with no spaces - the underline character is usually used for a space. Names are often case sensitive, as are all other addresses and file names on the Internet

The "where" section is a computer's address (also called Domain name) and is described below... 

Uniform Resource Locator (URL)  A URL is of the form:  Service type://where/more 

Service Type 


The "where" section of a URL is the address of a computer somewhere on the Web. It can be any combination of alphanumeric (and a few special) characters, with sections separated by dots (without spaces). 

  1. The first part of a web address is the computer name (generally www, but can be any name).
  2. Next is the organisation name. e.g. smh (Sydney Morning Herald).
  3. Then the type of organisation. com=commercial, org=Non profit organisation, gov=Government, edu=Educational, net=Network, etc.
  4. Finally the country code. None for USA as the net started there. au=Australia, uk=United Kingdom, etc.

E.G. is the computer named www at the commercial site for Burkes Back Yard in Australia. Note also that http:// does not have to be typed into most browsers (it is assumed). Also lower case and lack of spaces are very significant - addresses must be typed exactly as printed.

Actually, the real "where" address is numeric, e.g. is the same as and either can be used. Alphanumeric is normal but occasionally you will come across the numerals. 

More bits of the address 

These will normally comprise a folder/s and file or page identifier, usually with a ".htm" or ".html" extension, this being the convention for HTML files. A particular use of the "more" section is to identify a person's home page, where an identifier is often preceded by the tilde character, e.g.

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Jan 2003