The Internet

We all know the Internet today is a widespread information infrastructure, a global network spanning the word offering information on almost every topic. 

Where did it come from and how did it happen?

In 1962, J.C.R. Licklider was the first head of the computer research program at DARPA (Defense Advanced Research Projects Agency) or ARPA (Advanced Research Projects Agency), the US government agency. He introduced his "Galactic Network" concept - a globally interconnected set of computers through which everyone could quickly access data and programs from any site. He also convinced his successors at DARPA of the importance of this networking concept.

Researches, development works and experiments from the first however small wide-area computer network created with a low speed dial-up telephone line in1965, through the core protocols and technology development of TCP/IP (Transmission Control Protocol/Internet protocol) in the mid 70s and the 80s, the networking concept evolved to the advanced Internet nowadays.

More from The Internet Society
What is the Internet? how does it work? The history of internet ...

The Internet is simply a series of interconnected computers and networks all communicating by using TCP/IP, the standard protocol that allow data to cross the network from one to another.

How It Works -

• At the bottom layer is the physical transport such as Ethernet, modem or leased line



• IP (Internet Protocol) - the lowest logical level of the Internet.
  IP handling addressing and routing and keeping track of the IP packets of information.



• TCP (Transmission Control Protocol) - a high level protocol that establishing and managing connections between two systems. It is used for most high-level Internet applications.



• High-level Internet applications such as -



• HTTP (HyperText Transfer Protocol) a set of rules for exchanging files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. Web Browsers are HTTP client.



• Email systems using SMTP (Simple Mail Transfer Protocol) for sending mails and POP3 (Point Of Presence) for receiving mails



• FTP File Transfer Protocol for data transfer from one network to another such as down load a file.

Internet Connection

Providing we have a modern computer system, we need a Dial-up account with an ISP (Internet Service Provider) in order to access the Internet because the ISP acts as gateway connecting us to the backbone of Internet.

The most common way to connect to the ISP is dial up via telephone line hence so-called dial-up connection.

How fast we can retrieve information on the Internet depend on the bandwidth (the speed of transmission) on the dial-up connection and the density of the Internet traffic.

Options of connection to the ISP:

• Analogue Transmission / Standard MODEM


A MODEM is required at both ends of the transmission (one at the user's end and the other at the ISP's end), maximum speed is up to 56kbps.

A 56k Modem rarely can work at it's full speed 57,600 bits per second when connected to the Internet nowadays because of -


• Internet Traffic Congestion


Although we can do very little about the congestion of Internet traffic but just to avoid to logon at peak hours see The Internet Traffic Report monitors


• Connection Bandwidth - how fast data flows on a given transmission path


You can test your connection bandwidth with Cnet's Bandwidth Meter
Guess what bandwidth you will get before the test result is shown and don't be surprised if you don't get 56k even you have a 56K Modem !

or

Choose a quiet time (when the Internet's traffic is not so busy) to download a file about 1MB to 2MB in size from a website, you then will see the Windows' download dialog showing you the speed your computer is receiving data through the Internet.


• User Ratio (User per Modem ratio) set by ISP



•   5:1 is the lowest in the industry and permits a fast connection
• 10:1 is a norm with an average-speed connection when the Modem is not fully loaded with 10 users, otherwise best to avoid logon at peak hours



• Digital Transmission / ISDN (Integrated Services Digital Network)


ISDN is a set of standards for digital transmission over ordinary telephone copper wire as well as over other media. ISDN requires adapters at both ends in order to delivery the high-speed transmission up to 128Kbps.

More about ISDN    Broadband ISDN (BISDN)

Broadband Service Provider


• Digital Transmission / ADSL (Asymmetric Digital Subscriber Line)


ADSL operates over a normal telephone line. The signal is carried by two DSL modems, one at the user end and one in the local exchange. The modems are designed to exploit the physical transmission capabilities of the copper line to achieve higher downstream data rates from 512 up to 6Mbps. 

A 'splitter' (which is a filter), one at the user end and one at the exchange end that separates the telephony signal from the DSL signal. This means that telephone calls can be made at the same time that data is being sent or received.  More about ADSL



• Cable Modem (C-Modem) for cable users


Using Cable Modem network is like connecting to the Internet among a block of houses of neighbours like the cable TV. The downstream data speed of 512 Kbits/sec and upload speed of 256 Kbits/sec is allocated to each account user. The data speed will be shared among the users in that block if there is more than one user online.



• Satellite Internet access


It is normally regarded as an expensive option. More about Satellite Internet access

With the advance of ADSL and Cable Modem, being 'always on' permanent connection opens up your system for external attacks. A software or hardware Firewall is recommended for security and protection

Choosing a Dial-up ISP