Chapter 2 Technology Infrastructure The Internet and the World Wide Web

The Internet and the World Wide Web FTP USENET WWW TELNET THE INTERNET HTTP Servers (Hypertext Transfer Protocol) Web Browsers (Internet Explorer, Netscape Navigator, Firefox)) Web Pages with hyperlinks

Growth the World Wide Web

World Wide Web Components  Packet Switching/Routing  Networks (LANS & WANS)  TCP/IP Communications Protocol  Client/Server Computing  Web Pages

Internet Backbone – U.S. Source:

Internet Backbone - Global

Routing Demo

Internet Connectivity

TCP/IP Protocol IP TCP HTTP, FTP, Telnet, DNS,SMTP Network Layer Transport Layer Application Layer SSL (Secure Sockets Layer) Network Data Packets The TCP/IP protocol controls assembly & disassembly of a file into packets for transmission over the Internet

Packet-Switching Networks Digital data are sliced into packets, and sent over network on different paths then reassembled at their destination. Routers: special purpose computers that interconnect computer networks and route packets to their ultimate destination Routers use routing algorithms to ensure packets take the best available path

IP Addressing Internet Protocol Version 4 (IPv4) –A 32-bit number to identify computers connected to the Internet Sample IP Address:

TCP/IP Application Suite HTTPFTP Web Pages File Transfer

TCP/IP Application Suite SMTPTELENET Terminal Emulation

ICANN ICANN is responsible for the global coordination of the Internet's system of unique identifiers such as domain names and addresses

Domain Names A Domain Name is a set of words assigned to a specific IP address. Protocol Name + Domain Name or IP Address = Uniform Resource Locator (URL). ftp://

Unrestricted ( e.g.,.com..net,.org) Restricted (.edu,.gov,.mil) Country (e.g.,.us,.cc,.tv) New Domain Names ( e.g.,.aero,.biz,.coop,.info,.jobs,.mobi,.museum,.name,.pro,.travel) Vanity Domain names (e.g.,.tv) Domain Names

Domain Names

County Code Domain Names

Accredited Registries

Domain Naming Issues 2-63 Characters (A-Z, 0-9, “-”) No “-” at Beginning or End Brand Names & Cybersquatting Dot-Com is Most Respected Not Case Sensitive Typically Represents a Business, or Product or Service Name, + Other Uses About Registration & Name Ownership

Client-Server Computing Web Client Computer –Runs software called Web client software or Web Browser software Web Server Computer –Runs software called Web server software

Domain Name System (DNS) The Domain Name System (DNS) associates Domain Names with IP Addresses. Functionally, it’s a Web Page Phone Book DNS URL is Resolved to IP Address Hosting Server IP Address abc.com Home Page IP Addresses Web Pages

Whois Search Whois is used to determine who the URL is registered to.

Electronic Mail Protocols SMTP (Simple Mail Transfer Protocol) - specifies the format of a mail message POP (Post Office Protocol) – used to retrieve from a server. MIME (Multipurpose Internet Mail Extensions) – provides Support for graphics, audio & video content.

W3C The World Wide Web Consortium (W3C) is an international consortium that develops protocols and guidelines for the Web.World Wide Web Consortium

Standard Generalized Markup Language (SGML) Offers a system of marking up documents that is independent of any software application. Used to Create Other Markup Languages.

Hypertext Markup Language (HTML) Prevalent markup language used to create Web pages HTML tags are interpreted by a Web browser and are used by it to format the display of the text HTML links can be structured as: –Linear hyperlink structures –Hierarchical hyperlink structures

Extensible Markup Language (XML) It includes data management capabilities that HTML cannot provide XML, HTML & XHTML: –XML does not have pre-defined tags. –XML tags do not specify how text appears on a Web page. –XHTML is a markup language written in XML that has a stricter syntax than HTML.

Other Web Page Functionality Scripting Languages: JavaScript, JScript, Perl, and VBScript. Cascading Style Sheets (CSS): Provide pre-defined Web page formatting.

Intranets and Extranets Intranet –Interconnected network that does not extend beyond the organization that created it Extranet –Intranet extended to include entities outside the boundaries of an organization –Connects companies with suppliers, business partners, or other authorized users

Networks Public network –A network available to the public. Private network –A private, leased-line connection between two companies that physically connects their intranets.

Virtual Private Network (VPN) VPN –An extranet that uses public networks and their protocols –VPN software must be installed on the computers at both ends of the transmission

Internet Connection Options Bandwidth –Amount of data that can travel through a communication line per unit of time Net bandwidth –Actual speed that information travels

Voice-Grade Telephone Connections POTS, or plain old telephone service –Uses existing telephone lines and an analog modem –Provides bandwidth between 28 and 56 Kbps Digital Subscriber Line (DSL) –Connection methods that do not use a modem Integrated Services Digital Network (ISDN) –Bandwidths between 128 Kbps and 256 Kbps

Broadband Deployment Broadband defined as greater than 200 Kbps Asymmetric digital subscriber line (ADSL) Cable Modem Fixed Point Wireless Broadband DSL Satellite

Leased-Line Connections DS0 (digital signal zero) –Telephone line designed to carry one digital signal T1 line (also called a DS1) –Carries 24 DS0 lines and operates at Mbps Fractional T1 –Provides service speeds of 128 Kbps and upward in 128-Kbps increments T3 service (also called DS3) –Offers Mbps

Wireless Connections Bluetooth Designed for personal use (Personal Area Networks) over short distances (Up to 100 meters) Speeds of up to 722 Kbps Devices can discover each other and exchange information automatically

Wireless Ethernet (Wi-Fi – Wireless LANs) Protocols based on IEEE Standard

Mobile Networks Cellular - Third-generation (3G) Technology Cell Phones Mobile commerce (m-commerce)

Internet 2 Internet2 or UCAID (University Corporation for Advanced Internet Development) – A nonprofit consortium of universities and corporations which is developing an advanced, high-speed network for education and research. Not to be confused with Web which is the unofficial “social networking & collaborative” Web.

Social Networking (Web 2.0) Wikipedia, Blogs, RSS Feeds, Facebook, YouTube Nearly 2 in 5 U.S. Internet Users Watched a YouTube Video in September Nearly 70 million people viewed more than 2.5 billion videos on YouTube.com. More than 38 million people viewed approximately 360 million videos on MySpace.com Source: comScore Video Metrix

Wikipedia

Blogs

RSS Feeds

Second Life – Web 2.0 in Action

Second Life – Web 2.0 in Action