Week 6: Internet Infrastructure

What is Internet?

  • The internet is a telecommunications network that uses telephone lines, cables, satellites and wireless connections to connect computers and other devices to the World Wide Web. All modern computers can connect to the internet, as can many mobile phones and some televisions, video game consoles and other devices.


What is World Wide Web?

  • The World Wide Web, or simply Web, is a way of accessing information over the medium of the Internet. It is an information-sharing model that is built on top of the Internet. 
  • The Web uses the HTTP protocol, only one of the languages spoken over the Internet, to transmit data. 
  • Web services, which use HTTP to allow applications to communicate in order to exchange business logic, use the the Web to share information. 
  • The Web also utilizes browsers, such as Internet Explorer or Firefox, to access Web documents called Web pages that are linked to each other via hyperlinks
  • Web documents also contain graphics, sounds, text and video.

Internet VS WWW



A Hierarchy of Networks



Internet Service Provider (ISP)


  • ISP also called IAP (Internet Access Provider)
  • Company that provides access to the internet.
  • Usually ISP provide software package, username, password and access phone number and modem.
  • ISP are connected to one another through Network Access Point (NAPs)
  • Example of ISP: TM


Internet Protocol







Domain Name System





HTTP

  • Hyper Text Transfer Protocol
    • HTTP defines how messages are formatted and transmitted and what actions Web servers and browsers should take in response to various command.


Type of Internet Connection and Access


  • Dial Connection 

    • Used a conventional dial up modem connected to standard telephone jack with regular twisted-pair cabling
    • Usually used with home computers.
    • Advantages: inexpensive hardware, ease to set up
    • Disadvantages: slow connection

  • Cable

    • Used a direct connection
    • Usually found in office
    • Advantages: Fast

  • Satellite internet access

    • Used a direct connection
    • Slower and more expensive than cable internet access.
    • Required transceiver satellite outside the home or building to receive and transmit data. 
    • Availability: Anywhere there is clear view and where a satellite dish can be mounted and received signal.

  • Fixed  wireless

    • Similar to satellite internet.
    • But it uses radio transmission tower instead of satellite tower.
    • Availability: Selected areas where service is available.

  • Broadband 

    • high-speed Internet connection.
    • Broadband transmits data digitally, which means a modem or similar device is required on your end to translate the data packages.
    • Several different types of broadband services are available with their own advantages and disadvantages. 

  • Mobile wireless

    • Virtually anywhere cellular phone service available.







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