1 CSC317/318 INTERNET PROGRAMING / DYNAMIC WEB APPLICATION DEVELOPMENT CHAPTER: HOW DOES INTERNET WORKS? Siti Nurbaya Ismail Faculty of Computer & Mathematical Sciences, Universiti Teknologi MARA (UiTM), Kedah | A | | |

How Does Internet Works? Internet Service ProviderConnecting to InternetProtocolsHow does data travel through the Internet?Client/Server CommunicationHTTP Communication for Web 2

How Does Internet Works? What is the Internet? 3  Computer network the system in which a large number of separate but interconnected computers serve all of the needs a collection of interconnected networks network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic and optical networking technologies

How Does Internet Works? Intranet? Extranet? Intranet –A PRIVATE computer network that belongs to an organization that can be accessed ONLY by authorized persons Extranet –A part of an organization’s INTRANET that is extended to user outside the company 4

How Does Internet Works? Internet Service Provider 5  Internet Service Provider = ISP –Company that provide the Internet connection

How Does Internet Works? Internet Service Provider 6  ISPs in Malaysia? –Answer: Quite a few Wired: * TMNET * Jaring * Maxis Wireless: * Jaring * Maxis * Celcom * Digi * iZZi

How Does Internet Works? Connecting To Internet  Wired –Fixed line –Cable modem (dial-up | xDSL) –Network Interface Card (NIC) –LAN Cable –Fiber optic backbone from Server Exchange to CPE. Provided by ISP. In this case provided by TM because TM own all underground cabling in Malaysia. 7

How Does Internet Works? Connecting To Internet  Wireless –IEEE Types: (A | B | G | N) or so called “Wi-Fi” Access Point connected to wired LAN Clients (notebook | desktop) connected via wireless device –Embedded in the notebook or external device such as USB wireless Adapter and PCI wireless card Coverage: (Small | Medium) because usually setup in an office, in a park or public spots 8

How Does Internet Works? Connecting To Internet  Wireless –IEEE Worldwide Interoperability for Microwave Access (WiMAX) Also known as Wireless MAN Provides wireless internet connection over long distances Which companies won WiMAX license in Malaysia last year? –Bizsurf, Packet One Networks, Asiaspace Dotcom, Redtone-CNX Broadband, P1 9

How Does Internet Works? Connecting To Internet  Wireless –Satellite Internet Access Use mobile phone coverage: (GPRS | 3G | HSDPA) Modem (Supported mobile phone or USB Modem) Quite well-known these days ISPs: –Maxis Broadband –Celcom Broadband –Digi Broadband 10

How Does Internet Works? Connecting To Internet  Universal Resource Locator (URL) –An address to the current location of information protocol://host[:server port]/path/ –Example: –Web browser uses the URL address to retrieve a document over the network 11

How Does Internet Works? Connecting To Internet  Domain Name –A name that uniquely identifies a website on the Internet –As a substitute for IP Address of the website –Example: URL: Domain Name: uitm.edu.my IP Address: –Which one is easier to remember? Domain name or IP Address? –Top-level domain (TLD) names Infrastructure (iTLD):.root,.arpa. Generic TLD (gTLD):.com,.edu,.net,.gov, etc. Country Code (ccTLD):.my,.uk,.id,.sg, etc.  Domain Name Server (DNS) –Translates domain name to IP Address 12

How Does Internet Works? Connecting To Internet  Host Name –A host is a (computer | device) that is connected to a network –Each host has a name, therefore, we call it host name –Host name uniquely identifies a host on a network without using its IP Address –Example: 1 computer named “uitmpc1” is connected to a UiTM’s network “uitmpc1” has a unique IP Address which is “ ” You are able to access or find “uitmpc1” using its host name or IP Address 13

How Does Internet Works? Protocol  Protocol –A set of rules that enables computers to connect and transmit data to one another over the network/Internet –Examples: Transmission Control Protocol (TCP) Internet Protocol (IP) Hypertext Transfer Protocol (HTTP) File Transfer Protocol (FTP) Simple Mail Transfer Protocol (SMTP) 14

How Does Internet Works? Protocol  Transmission Control Protocol (TCP) −TCP enables two hosts to establish a connection and exchange streams of data. −TCP guarantees delivery of data and also guarantees that packets will be delivered in the same order in which they were sent.  Internet Protocol (IP) –IP specifies the format of packets, and the addressing scheme. –IP by itself is something like the postal system. It allows you to address a package and drop it in the system, but there's no direct link between you and the recipient.  TCP/IP –? 15

How Does Internet Works? Protocol  Hypertext Transfer Protocol (HTTP) –underlying protocol used by the World Wide Web –defines how messages are formatted and transmitted, and what actions Web servers and browsers should take in response to various commands. –Example, when you enter a URL in your browser, this actually sends an HTTP command to the Web server directing it to fetch and transmit the requested Web page  File Transfer Protocol (FTP) –protocol for exchanging files over the Internet –most commonly used to download a file from a server using the Internet or to upload a file to a server  Simple Mail Transfer Protocol (SMTP) –a protocol for sending messages between servers 16

How Does Internet Works? How does data travel through the Internet? At the most basic level possible, the diagram shows the step that brought the web page to your screen. 17

How Does Internet Works? How does data travel through the Internet? Your Computer sends page request and then translates the information sent back into the words and images that make up the Web page 2. ISPs provide internet connection for home user and business or organization for a fee 3. Routers are computers that receive information and forward it to the correct destination over the most efficient route available at that moment 4. Web Servers are computers that answer your request for a particular Web page with the information required to build that page on your computer

How Does Internet Works? How does data travel through the Internet? 19 Bear in mind, data travel on the network/Internet in digital form (0|1)

How Does Internet Works? Client/Server Communication 20

How Does Internet Works? Client/Server Communication 21

How Does Internet Works? Client/Server Communication  Some of the protocols involved: –Hyper Text Transfer Protocol (HTTP) Port 80 Simple protocol for file transfer over the network/Internet –File Transfer Protocol (FTP) Port 21 Standard method for (sharing | downloading) files over the Internet for many years Commonly used to transfer Web page files from their creator to server. * Note: Do you want to know the other port numbers? Visit

How Does Internet Works? Client/Server Communication  Common software requirement at the client side: Web browser –Internet Explorer –Firefox –Opera –Konqueror –Safari  Common software requirement at the server side: Web server –Microsoft Products: PWS or IIS –Open Source Products: Apache, Tomcat, etc. 23

How Does Internet Works? HTTP Communication for Web  Two types of Web: –Static Web The contents of the web are fixed Hard coded in the HTML –Dynamic Web Dynamic content The web is connected to the database Required client and server side scripting 24

How Does Internet Works? HTTP Communication for Web 25

How Does Internet Works? Bibliography(website)         