Internet Fundamentals: Connectivity and Protocols

Understanding the Internet

The Internet is known and loved by everyone (except those who are still waiting for something to download) and it is the biggest growth area in technology at the moment. The Internet is an international network of computers.

It is basically a very big Wide Area Network of computers. It was originally developed by the U.S. Government to improve communication between its military computers. In the beginning, only government "think tanks" and a few universities were linked. It was an emergency military communications system.

How the Internet Functions

1. Most people access the Internet using a PC connected to a normal telephone line. Computers are attached to a telephone line via another piece of kit called an ADSL modem or DSL modem, or usually called a router.
2. To connect to the Internet, you use your modem-router to connect to an Internet Service Provider (ISP). All the information sent from your PC goes via the ISP.
3. The two most important pieces of software you need are a web browser to display web pages and an e-mail client, which transmits and receives e-mail from a PC.
4. Web browsers sometimes need plug-ins (small programs) before they can play certain types of multimedia files, like videos, for example.

Factors Affecting Internet Speed

The speed of an Internet connection is measured in megabits per second. Three things determine the speed of access:

• Modem-Router Speed: Modern domestic modem-routers are able to work up to 6 Mbps, but can go to 100 Mbps.
• The Telephone Line: The line between your home and the ISP server is often an old copper cable that can be very slow. In big cities, they use optic fibers so data moves faster.
• The Volume of Traffic: The more people use the Internet, the slower the speed of access.

Wireless Network Benefits and Drawbacks

Advantages of Wireless Networks

• You don't need cabling.
• With Wi-Fi, one access point can cover an entire floor or even a building.
• You can work anywhere within range of the access point.
• You can link to a network away from home or your office.

Disadvantages of Wireless Networks

• Fixed LANs can run at 1000 Mbps. Wireless networks are slower, and the further you are from an access point, the lower the rate.
• While there are savings on the cost of cabling, wireless NICs are a bit more expensive than the wired versions.
• Interference: Other users might be able to intercept your data if you are using an unencrypted channel. Encryption programs like Wired Equivalent Privacy (WEP) can help.

Understanding TCP/IP Protocol

Divide and conquer: that is the philosophy of the Internet. If you are at home in front of your computer, that computer is called a client. Then you start the browser (a client program) and request some information, for example, your favorite sports webpage that is located on a remote computer (a server). So, we have a client-server interaction. The browser searches for the remote computer on the Internet and passes the request to the server. The server then checks your request and tries to locate the HTML file on its hard disk. On finding it, the server sends this file to your computer.