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Explore key web concepts including bandwidth, digital vs analog, browser URL, DNS, cache, IP addresses, and client/server computing. Understand the fundamentals to navigate the online landscape effectively.
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Intro to the web process Main concepts: Bandwidth, Digital vs. Analog Aerial vs. Terrestrial, “The Negroponte Switch” ISDN, ADSL Synchronous vs. A-Synchronous DOMAIN NAMES Browser URL, IP, DNS, Cache, Log, Firewall, plug-in Three last frameworks Strategy/Technology Age/Audience size Is the Web all there is?
The Paradigm Shift:Reduce Cost, Improve Service in Order Management CURRENT (Company-Defined Access) • 800 • Mail COMPLETETHE CALL Information Database Customer Sales and Service History Database EMERGING (Customer-Defined Access) COMPLETE THE TRANSACTION The Web/Online Services Inventory Systems DeliverySystems • Fax • On-line Order Processing • 800 • Mail
The Paradigm Shift:Reduce Time-to-Market in Supply Chain Management CURRENT ENTERPRISE FOCUS 800 Customer Manufacturer Retailer Supplier CollaborativeSystems NEAR TERM PARTNER FOCUS 800 Fax On-line Supplier Retailer Manufacturer Customer CUSTOMER FOCUS Virtual Shelf Shared Market Data EMERGING The Web Customer Manufacturer Supplier
Browsing 1011.5 • There exist a variety of browsers Explorer, Netscape, Mosaic, Lynx, Opera, Offline browsers • HTML, and therefore browsers, are not Page Definition Language or systems • Looking for dynamic, interactive presentation • Hence the role of PDF, Shockwave, Java, DHTML, VRML, SSI, PHP, ASP, CGI, etc.
Browsing 1015 an IP address is a 32-bit number that identifies each sender or receiver of information that is sent in packets across the Internet. The IP address is usually expressed as four decimal numbers, each representing eight bits, separated by periods. This is sometimes known as the dot address and, more technically, as dotted quad notation
Browsing 1016 For a more extended discussion of IP addressing, see "Understanding IP Addressing: Everything You Ever Wanted to Know, by Chuck Semeria. At: http://www.3com.com/nsc/501302.html Longest Match forwarding Algorithm Dotted Decimal Notation Subnetting VLSM
Browsing 10114 The cache is often accessible later on. Originally there for speed sake, now makes for a security and privacy nightmare
The Internet: Key Technology Concepts • Federal Networking Council definition of Internet highlights three important concepts that are the basis for understanding the Internet: • Packet switching • TCP/IP communications protocol • Client/server computing
Packet Switching • A method of slicing digital messages into packets, sending the packets along different communication paths as they become available, and then reassembling the packets once they arrive at their destination • Uses routers: special purpose computers that interconnect the computer networks that make up the Internet and route packets to their ultimate destination • Routers use computer programs called routing algorithms to ensure packets take the best available path toward their destination
TCP/IP (Transmission Control Protocol/ Internet Protocol) • Protocol: A set of rules for formatting, ordering, compressing, and error-checking messages • TCP: Establishes the connections among sending and receiving Web computers, handles the assembly of packets at the point of transmission, and their reassembly at the receiving end • IP: Provides the Internet’s addressing scheme • TCP/IP is divided into 4 separate layers: • Network Interface Layer • Internet Layer • Transport Layer • Application Layer
IP Addresses • Internet address (also called IP address): a 32-bit number expressed as a series of four separate numbers marked off by periods, such as 201.61.186.227 • IPv4 the current version of IP. Can handle up to 4 billion addresses • IPv6 (next generation of IP) will use 128-bit addresses and be able to handle up to 1 quadrillion addresses
Routing Internet Messages: TCP/IP and Packet Switching Figure 3.5, Page 123
Domain Names, DNS, and URLs • Domain name: IP address expressed in natural language • Domain name system (DNS): allows numeric IP addresses to be expressed in natural language • Uniform resource locator (URL): addresses used by Web browsers to identify location of content on the Web
Client/Server Computing • Model of computing in which very powerful personal computers (clients) are connected in a network with one or more server computers that perform common functions for the clients, such as storing files, software applications, etc.
Insight on Business: Peer-to-Peer Computing Goes to WorkClass Discussion • How does Peer-to-Peer (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? • Why does P2P networking permit users to remain anonymous? Is this a good thing?
Other Internet Protocols • HTTP: Used to transfer Web pages • SMTP, POP, and IMAP: Used to send and receive e-mail • FTP: Permits users to transfer files from server to client and vice versa • Telnet: Program that enables a client to emulate a mainframe computer terminal • SSL: Protocol that provides secure communications between client and server
Utility Programs • Ping: Utility program that allows you to check connection between client and server • Tracert: Utility program that allows you to follow part of a message sent from a client to a remote computer • Pathping: Utility program that combines functionality of Ping and Tracert
The Internet Today • Client/server computing model, coupled with hourglass, layered architecture of Internet has allowed Internet to handle explosive growth without disruption • Hourglass/layered architecture – 4 layers: • Network Technology Substrate • Transport Services and Representation Standards • Middleware Services • Applications
The Hourglass Model of the Internet SOURCE: Adapted from Computer Science and Telecommunications Board (CSTB), 2000.
Internet Network Architecturee • Backbone: Consists of high-bandwidth fiber-optic cable owned by a variety of Network Service Providers (NSPs) • Internet Exchange Points (IXPs): Hubs where backbones intersect with regional and local networks, and where backbone owners connect with one another • Campus area networks (CANs): Local area networks operating within a single organization that leases Internet access directly from regional or national carrier • Internet Service Providers: Lease Internet access to home owners and businesses
Internet Service Providers (ISPs) • Retail providers that deal with “last mile of service” • Major national ISPs include AOL, MSN, and AT&T WorldNet, etc. • Offer both narrowband (traditional telephone modem connection at 56.6 Kbps) and broadband (service based on DSL, cable modem, T1 or T3 telephone lines, and satellite)
Broadband Service Choices • Digital Subscriber Line (DSL): Telephone technology delivers high-speed access through ordinary telephone lines • Cable modem: Cable television technology piggybacks digital access to Internet on top of analog video cable line • T1 and T3: International telephone standards for digital communication that offer guaranteed delivery rates • Satellite: high-speed downloads, but no upload available
Intranets and Extranets • Intranet: TCP/IP network located within a single organization for purposes of communication and information processing • Extranet: Formed when firms permit outsiders to access their internal TCP/IP networks
Who Governs the Internet? • A number of different organizations that influence Internet and monitor its operations including: • Internet Architecture Board (IAB) • Internet Corporation for Assigned Names and Numbers (ICANN) • Internet Engineering Steering Group (IESG) • Internet Engineering Task Force (IETF) • Internet Society (ISOC) • World Wide Web Consortium (W3C)
Domain names • There are currently over 6 million registered domain names • About half use the .com extension • Approximately 70,000 new every week • Internet Corporation for Assigned Names and Numbers (ICANN)
Governance (?):Keeper(s) of the Names • InterNIC: Internet Network Information Center, funded by NSF. • Since 1993, Network Solutions, Inc. (NSI), has been the only provider of domain name registration services in the .com, .net and .org top-level domains: Http://www.networksolutions.com • October 1998: the "Shared Registration System.” : Five new registrars - in addition to NSI – were accredited to register domain names in .com, .net, and .org
ICANN • The Internet Corporation for Assigned Names and Numbers (ICANN) is the non-profit corporation that was formed to assume responsibility for the IP address space allocation, protocol parameter assignment, domain name system management, and root server system management functions previously performed under U.S. Government contract by IANA and other entities.
Network Solutions $119 to reserve for two years $70 to register
New Governance • Information on the implementation of NSI's Shared Registration System will be available at www.nsiregistry.com. • Information about ICANN and ICANN's registrar accreditation process is available at www.icann.org. • Information regarding the United States Government's efforts to privatize the management of the domain name system and increase competition in domain name registration services is available at www.ntia.doc.gov.
New Domain Names (TLDs) in 2001 • .biz • .info • .name • .pro • .coop • .aero • .museum Also… foreign language, and foreign administration
Name already taken? • Don’t despair • Cybersquatters: http://www.domainreseller.com, http://www.domainbook.com, http://domainrush.com • “RealNames” and “Netword” schemes • New TLD (Top Level Domains) just around the corner, or already allowed: .info, .md, .web, .store etc. • UltraNeoColonialism: set up shop in Austria or Tonga: http://welcome.to http://visit.at http://fly.to etc.
Three last frameworks... The strategy-technology linkageInformation Age and Audience SizeWho to Whom and When