The Internet Technological Background

Topic Objectives At the end of this topic, you should be able to do the following: Able to define the Internet Able to explain the difference between packet switching and circuit switching communications methods Able to define a protocol and list examples of Internet protocols Able to describe the functions of TCP and IP Able to explain the purpose of IP addresses, domain names and URL (universal resource locators) Able to explain the advantages of the client / server architecture Able to explain the difference between intranet and extranet

The Internet Definition An interconnected network of thousands of networks and millions of computers linking businesses, educational institutions, government agencies, and individuals together Internet comes from the word internetwork or the connecting together of two or more computer networks

The Internet Key Technology Concepts Prior to the Internet and the use of packet-switching, early computers networks used leased, dedicated telephone circuits to communicate with each other Circuit switching A dedicated, complete point-to-point circuit is put together for communications to take place Dedicated circuit-switching techniques were expensive and wasted available communications capacity (circuit maintained even when there is no data sent at a given time)

The Internet Key Technology Concepts The Internet uses packet switching as a method of communicating between computer networks Packet Switching Method of slicing digital messages into parcels called “packets,” sending the packets along different communication paths as they become available, and then reassembling the packets once they arrive at their destination

Key Technology Concepts Protocol A set of rules for formatting, ordering, compressing, and error-checking messages

Key Technology Concepts TCP/IP Solution for handling packets on the Internet server software TCP/IP is implemented in Web software called server software TCP (Transmission Control Protocol) The protocol that does the following establishes the connections among sending and receiving Web computers Handles the assembly of packets at the point of transmission, and their re-assembly at the receiving end IP (Internet Protocol) IP Address The protocol that provides the addressing scheme for the Internet

Key Technology Concepts Domain Names IP addresses can be represented using natural language because difficult to remember a 32-bit number DNS or Domain Name System allows expressions such as “cnet.com” as substitute for a 32-bit number URL or Universal resource locators Addresses used by Web browsers to identify the location of content on the Web Contains the protocol to be used when accessing the address, followed by the location Example

Key Technology Concepts Client / Server Computing Model of computing where personal computers called clients are connected together in a network with one or more server computers 70 million host server hundreds of millions of client The Internet contains over 70 million host server computers that stores Web pages and other contents that are accessed by a million local area networks and hundreds of millions of client machines worldwide

Internet Protocols and Utility Programs Internet ProtocolsUsage HTTP Protocol used for transferring Web pages. Runs on the Application Layer of the TCP/IP model. HTTP - Hyper Text Transfer Protocol. SMTP Protocol used to sending to a server. SMTP (Simple Mail Transfer Protocol) is a protocol used to send mail to a server. POP (Post Office Protocol) is used by the client to retrieve mail from an Internet server. FTP Permits users to transfer files from the server to their client machine, and visa versa. FTP - File Transfer Protocol. Secure Socket Layer (SSL) Secures communications between the client and the server

Internet Service Providers Two types of ISP services Narrowband (traditional telephone modem connection operating at 56.6 Kbps) Broadband (communications technology that permits clients to play streaming audio and video files at accepted speed of above 100 Kbps) In Malaysia Jaring Maxis net TMnet

Intranets and Extranets Intranet a TCP/IP network located within a single organization for purposes of communications and information processing Internet technology privately used within an organization Extranet Intranet that gives limited access to users outside the organization When firms permit outsiders to access their internal TCP/IP networks

The World Wide Web Web client Any computing device attached to the Internet that is capable of making HTTP requests and displaying HTML pages Web servers Software that enables a computer to deliver Web pages written in HTML to client machines on a network that request this server by sending an HTTP request The leading brands of Web server software are Apache and Microsoft NT Server software

The World Wide Web Specialised web servers Database servers Server designed to access specific information with a database Ad servers Server designed to deliver targeted banner ads Mail servers Server to provide mail messages Video servers Server that serves video clips

The Internet and the Web Features Enables messages containing text, images, sound and video clips to be transferred from one Internet user to another Search engines Identifies Web pages that appear to match keywords, also called queries, typed by the user and provides a list of the best matches Intelligent agents (Bots) Software programs that gather and/or filter information on a specific topic and then provide a list of results for the user Chat Enables users to communicate via computer in real time, that is, simultaneously among several users

The Internet and the Web Features Instant messaging Displays words (from the sender) typed on a computer almost instantaneously. Recipients can then respond immediately to the sender the same way, making communication more like a live conversation than is possible through Streaming media Enables music, video, and other large files to be sent to users in chunks so that when received and played, the file comes through uninterrupted Cookies A tool used by Web sites to store information about a user by sending a small text file to the user’s computer so that information from the site can be loaded more quickly on future visits

Internet and E-Commerce Emerging Features and Services Internet telephony A general term for the technologies that use Voice Over IP and the Internet’s packet-switched network to transmit voice and other forms of audio communications over the Internet

Internet and E-Commerce Emerging Features and Services Distance learning Educational institutions are now able to make courses and whole degree programs available online Digital video Future digital video networks will be able to deliver quality video over the Internet to computers and other devices Video teleconferencing Using the Internet will make this less costly than the present technology

Internet and E-Commerce Emerging Features and Services M-commerce applications Combining voice, data, images, audio and video on one wireless device using high bandwidth wireless and fiber-optic based Internet2