Thương mại điện tử - The Internet and The Web - Chapter-2

How does P2P networking differ from client/server networking? Why is P2P networking a potential money-saver for corporations and other organizations? What are some illegal uses of P2P networking? What are some legal uses of P2P networking? What other alternatives are there for streaming large video files?

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CSC 330 E-CommerceTeacher Ahmed Mumtaz Mustehsan GM-IT CIIT Islamabad Virtual Campus, CIIT COMSATS Institute of Information TechnologyT1-Lecture-3The Internet and The WebChapter-2Part-IT1-Lecture-3For Lecture Material/Slides Thanks to: Copyright © 2010 Pearson Education, IncObjectivesDefine the origin and evolution of the Internet.Identify the key technology concepts behind the internetDescribe the role of Internet protocols and utility programsExplain the current structure of Internet.Understand the limitations of todays internetDescribe the potential capabilities of Internet IIUnderstand how the world wide web worksDescribe how internet and web features and services support e-commerce.T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-3The Internet: Technology BackgroundInternetInterconnected network of thousands of networks and millions of computersLinks businesses, educational institutions, government agencies, and individualsWorld Wide Web (Web)One of the Internet’s most popular servicesProvides access to around billions, possibly trillions, of Web pagesT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-4The Evolution of the Internet 1961 - PresentInnovation Phase, 1964 -1974Institutionalization Phase, 1975 -1994Commercialization Phase,1995 - presentT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-5The Evolution of the Internet 1964 - 1974Innovation Phase: (1964 -1974)The basic building blocks were introduced such as; packet-switching hardware, client/server computing, and a communications protocol called TCP/IP The original purpose of the Internet, was to link large mainframe computers on different university/college campuses.This kind of one-to-one communication between campuses was previously possible only through the telephone system or postal mail. T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-6The Evolution of the Internet 1975 -1994Institutionalization Phase: (1975 -1994)Large institutions such as the US Department of Defense (DoD) and the National Science Foundation (NSF) provided funding to legitimate for the fledging invention called the Internet.DoD contributed $1 million to further develop the network into a robust military communications system so that it could withstand during nuclear war.In 1986, the NSF assumed responsibility for the development of a civilian Internet (NSFNET) and began a ten-year-long $200 million expansion program.T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-7The Evolution of the Internet (1995- Present)Commercialization Phase: (1995 – present)Government agencies encouraged private corporations to take over and expand both the Internet backbone and local services to ordinary citizens who were not students.By 2000, the Internet’s use had expanded well beyond military installations and research universities and came into the public domain.T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-8Source: instance of internet - active nodesT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-9The Internet: Key Technology ConceptsNetwork as Defined by NSF:Uses IP addressingSupports TCP/IPProvides services to users, in manner similar to telephone systemThree important concepts:Packet switchingTCP/IP communications protocolClient/server computingT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-10Packet SwitchingPacket Switching:Slices digital messages into packetsSends packets along different communication paths as they become availableReassembles packets once they arrive at destinationUses routers Special purpose computers that interconnect the computer networks make up the Internet and route packets.Routing algorithms ensure packets take the best available path toward their destination.Less expensive, wasteful than circuit-switching.T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-11Packet SwitchingPacket Switching Demo T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-12Key Concept Related to TCP/IPProtocolA set of rules and standards for data transferTransmission Control Protocol/Internet Protocol (TCP/IP) the core communications protocol for the InternetTCPProtocol that establishes the connections among sending and receiving Web computers and handles the assembly of packets at the point of transmission, and their reassembly at the receiving endIPprotocol that provides the Internet’s addressing scheme and is responsible for the actual delivery of the packetsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-13TCP/IPInternet Protocol (IP): Provides the Internet’s addressing scheme.Transmission Control Protocol (TCP): Establishes connections between sending and receiving Web computersHandles assembly of packets at point of transmission, and reassembly at receiving endFour TCP/IP Layers (hourglass model) Network Interface LayerInternet LayerTransport LayerApplication LayerT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-14The TCP/IP Architecture and Protocol SuiteT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-15Key Concept Related to TCP/IPNetwork Interface Layer: Responsible for placing packets on, and receiving them from, the network medium.Internet Layer Responsible for addressing, packaging, and routing messages on the InternetTransport Layer Responsible for providing communication with the application by acknowledging and sequencing the packets to and from the applicationT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-16Key Concept Related to TCP/IPApplication Layer Provides a wide variety of applications (HTTP, FTP, SMTP ) with the ability to access the services of the lower layers of TCP/IP.Internet addressInternet address expressed a unique number that appears as a series numbers separated with periods, such as 64.49.254.91 carrying the address of an individual machine on the internet.T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-17Internet (IP) AddressesHow 500 million people will be addressed?The answer is IP addressing version 4 (IPv4) used previously and IP addressing version 6 (IPv6) a new version introduced lately to accommodate more clients.IPv432-bit number IPv4 can handle 4 billion.Expressed as series of four sets of separate numbers marked off by periods e.g. 201.61.186.227 or 130.111.67.244Class B address: (130.111.67.244) Network identified by first two sets, computer identified by last set Class C address: (201.61.186.227)Network identified by first three sets, computer identified by last set T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-18T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, IncInternet (IP) AddressesIPv6A newer version of the IP protocol, called IPv6, has been developed. IPv6 provides for 128-bit addresses, or about 1 quadrillion(10 to the power15)Slide 3-19Checking your IPFrom start menu click RunType cmd in dialogue boxType ipconfigT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, IncSlide 3-20Routing Internet Messages: TCP/IP and Packet SwitchingThe Internet uses packet-switched networks and the TCP/IP communications protocol to send, route, and assemble messages. Messages are broken into packets, and packets from the same message can travel along different routes.T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-21Domain Names, DNS, and URLsDomain NameIP address expressed in natural languagecomsats.edu.pk  203.124.43.105Domain Name System (DNS)Allows numeric IP addresses to be expressed in natural language Uniform Resource Locator (URL)Address used by Web browser to identify location of content on the Webe.g., Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-22How to Pick a Domain NamePointer for picking domain namesIf you sell bricks, pick a domain name containing a word like brickConsider name length and ease of remembering the nameHyphens to force search engines to see keywords in your domain nameMake sure the domain name is easy for Web users to remember and findThe domain name should suggest the nature of your product or serviceThe domain name should serve as a trademarkThe domain name should be free of legal conflictsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-23Some memorable Internet namesGood namesAmazon.comEbay.comYahoo.comGoogle.comAlibaba.com Hotmail.comqwerty.comBad namesYadayada.comDoggles.comePet.comTeacherstalk.com“anything”online.comllanfairpwllgwyngyllgogerychwyrndrobwyll-llantysiliogogogoch.comClose to an existing nameGooogle.comGoggle.com T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-24How to Register a Domain Nameif you are interested a domain In Pakistan (.pk ) You may use :https://nexus.pk/pknic.phpIf you want to register an international domain .com you may try : Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-25How to Register a Domain Name in Pakistan?T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-26How to Register a Domain Name in Pakistan?T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-27How to Register an international Domain Name ? T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-28How to Register an international Domain Name ? T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-29The Internet TodayInternet growth has boomed without disruption because it is based on some powerful applications using the following architecture:Client/server computing modelPear to Pear P2P ModelCloud Computing Hourglass, layered architectureNetwork Technology SubstrateTransport Services and Representation StandardsMiddleware ServicesApplicationsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-30Client/Server ComputingPowerful personal computers (clients) connected in network with one or more servers Servers perform common functions for the clients, such as Storing files, software applications, etc.T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-31Client ServerT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-32The New Client: The Emerging Mobile PlatformWithin a few years, primary Internet access will be through:NetbooksDesigned to connect to wireless InternetUnder 2 lbs, solid state memory, 8” displays$200–400SmartphonesDisruptive technology: Processors, operating systemsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-33Cloud ComputingObtain Software and hardware as ServiceFirms and individuals obtain computing power (hardware) and software over InternetE.g., Google AppsFastest growing form of computingRadically reduces costs of:Building and operating Web sitesInfrastructure, IT supportHardware, softwareT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-34Cloud ComputingT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-35Cloud Computing ModelT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-36Other Internet Protocols and Utility ProgramsInternet protocolsHTTPE-mail: SMTP, POP3, IMAP, FTP, Telnet, SSLUtility programsPingTracertPathpingNSlookupSlide 3-37T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, IncHyperText Transfer Protocol (HTTP) is the Internet protocol used to transfer Web pages HTTP was developed by the World Wide Web Consortium (W3C).HTTP runsin the Application Layer of the TCP/IP modelAn HTTP session begins by the client’s browser requesting a resource, such as a Web page, from a remote Internet server. When the server responds by sending the page requested, the HTTPsession for that object ends. Web pages may have many objects such as graphics, sound or video files, frames, so each object must be requested by a separate HTTP message. The most common HTTP request message is Get, used to request a resourceOther Internet Protocols and Utility ProgramsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-38Simple Mail Transfer Protocol (SMTP) Is an Internet protocol used to send e-mail to a server. SMTP is a relatively simple, text-based protocol that was developed in the early 1980s. SMTP handles only the sending of e-mail.Other Internet Protocols and Utility ProgramsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-39To retrieve e-mail from a server, The client computer usesPost Office Protocol 3 (POP3)A protocol used by the client to retrieve mail from an Internet server and then delete themessages on the server, or retain them on the server.Internet Message Access Protocol (IMAP).IMAP is a more current e-mail protocol supported by all browsers and most servers and ISPs. IMAP allows users to search, organize, and filter their mail prior to downloading it from the server.Other Internet Protocols and Utility ProgramsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-40File Transfer Protocol (FTP)One of the original Internet services. Part of the TCP/IP protocol that permits users to transfer files from the server to their client computer, and vice versa.The files can be documents, programs, or large database files. FTP is the fastest and most convenient way to transfer files larger than 1 megabyte, which some e-mail servers will not acceptTelnetA terminal emulation program that runs in TCP/IP.The term Telnet also refers to the Telnet program, which provides the client part of the protocol and enables the client to emulate a mainframe computer terminal.Other Internet Protocols and Utility ProgramsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-41Secure Sockets Layer (SSL) is a protocol that operates between the Transport and Application Layers of TCP/IP and secures communications between the client and the server. SSL helps secure e-commerce communications and payments through a variety of techniques such as message encryption and digital signaturesOther Internet Protocols and Utility ProgramsT1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, Inc1-42P2P Class DiscussionHow does P2P networking differ from client/server networking? Why is P2P networking a potential money-saver for corporations and other organizations?What are some illegal uses of P2P networking?What are some legal uses of P2P networking?What other alternatives are there for streaming large video files?Slide 3-43T1-Lecture-3 Ahmed Mumtaz Mustehsan Copyright © 2010 Pearson Education, IncEndThe Internet and The WebChapter-2; Part-IT1-Lecture-3For Lecture Material/Slides Thanks to: Copyright © 2010 Pearson Education, Inc

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