Ch CHAPTER The Internet and the Web Irfan A. Ilyas Lecture 23

Ch 82 Points to cover  Introducing Internet  What is available on the Internet?  How to get connected with Internet?  Main Internet Facilities  World Wide Web  Electronic Mailing  Telnet  FTP  Gopher  Basic Working Model of Internet Services

Ch 83 Introducing Internet  Internet is  a connection of billions of computers (similar/ dissimilar) AND  the technologies (hardware/ software) which makes the whole setup interoperable.

Ch 84 What is available on the Internet?  Internet offers its users many services including  Communication with others  Using s, chatting (online messaging)  Shopping  Buy goods (and sell also)  Searching  Reading materials from real as well as virtual libraries  Entertainment  Games, Magazines, Interactive games etc.  Education (e-learnings)  Take online classes, get academic degrees.

Ch 85 How to get connected with Internet? Internet Service Provider (ISP)  An ISP is a commercial based organization  ISP charge their customers on hourly or fixed basis (unlimited access) How it works?  An ISP already had its computer connected with the Internet (backbone)  ISP allows their users to get connected with their local computer through a modem (telephone line)  After the user is connected, he becomes a part of the Internet (using different services)

Ch 86 …How to get connected with Internet?  Internet Service Providers( ISP )  Commercial Organizations  Available for all public  Centers are locally available to different areas [saves telephone charges].  Examples:  Saudi Online, Nasjeet etc.  Provide their customers with different numbers in Riyadh, Dammam, Jeddah etc.  University & Colleges  Only available for University attached people (students, faculty, staff)  Cannot be used from other localities  Example: KFUPM Connection

Ch 87 …How to get connected with Internet? Procedure for an ISP connections  Step#1: Getting Tel# & User Account  Subscribers are provided with  A telephone number to the ISP computer (local to the subscriber’s locality)  A username & password Saudi Online Prepaid Card with necessary information printed over it Note: pre-paid card from commercial ISPs normally have this information printed over it. Saudi Online User Name: Password: fdjfdkfkdjfddfd

Ch 88 …Procedure for an ISP connections  Step#2: System Setup for a dialup Connection  To prepare the subscriber’s (user) system for the connection, one of the following will also be provided:  A step-by-step manual setup procedure OR  A small program which will automatically do the required setup using a dialogue from the user.

Ch 89 …Procedure for an ISP connections  Step#3: Connecting the ISP  Using the dialup connection created in the last step,  Users dial the ISP number  System tries to connect (strange noise)  A successful connection message appears

Ch 810 …Procedure for an ISP connections  Step#4: Using Internet Facilities  Users can now start browsing etc. For more info:

Ch 811 Access Providers  Common way to attach to the Internet  Internet service providers (ISP)  National  Regional  Wireless

Ch 812 Main Facilities on Internet  World Wide Web  WWW allows Internet computers to exchange information objects (text/ pictures/ sound etc.) among each other through easy to use web pages.  WWW is an interface of Internet contents  Electronic Mailing  Sending and receiving messages using Internet  Telnet  Running programs on a remote computer (with its screen and keyboard control available locally)

Ch 813 ….Main Facilities on Internet  FTP  Transferring file from/ to a remote computer on the Internet  Gopher  It allows a client computer to access different resources on a server computer using a menu based interface (text based menus)  Not very popular after Web Interface became available.  Complex and painful.

Ch 814 The Basic Working Model of Different Internet Services Client Requests A Server Computer running the server program A Web Client Computer [running the client program] Server Responses  All Internet facilities work on the same principle as does the Web Service.  A client program is provided to Internet users  WWW: Internet Explorer, Netscape Navigator  Outlook Express, Netscape Mailer, Eudora Mail  FTP: Cute FTP for windows,  Telnet: Microsoft Windows Telnet client

Ch 815 Example: Client Programs  Cute FTP for Windows  Microsoft Window Telnet Client

Ch 816 … Working Principle of Different Internet Services  A server program must be running on the computers providing any related service.  Normally available as “Operating System Services”  Services start automatically when windows starts Service handling a Telnet Server Facility Service handling a WWW Server Facility

Ch 817 … Working Principle of Different Internet Services  The transaction mechanisms needed in each service will be different but already standardized  Simple Mail Transfer Protocol (SMTP)  FTP: File Transfer Protocol (FTP)  Gopher: Gopher Protocol  Web: Hyper Text Transfer Protocol (http)

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