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Chapter 3. Internet and World Wide Web. What is the Internet?. The largest network of networks in the world. Uses TCP/IP protocols and packet switching . Runs on any communication substrate. http://som.csudh.edu/cis/lpress/history/arpamaps/. Brief History of the Internet.
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Chapter 3 Internet and World Wide Web
What is the Internet? • The largest network of networks in the world. • Uses TCP/IP protocols and packet switching . • Runs on any communication substrate. • http://som.csudh.edu/cis/lpress/history/arpamaps/
Brief History of the Internet • 1968 - DARPA (Defense Advanced Research Projects Agency) contracts with BBN (Bolt, Beranek & Newman) to create ARPAnet (Advanced Research Projects Agency) • 1970 - First five nodes: • UCLA • Stanford • UC Santa Barbara • U of Utah, and • BBN
Brief History of the Internet • 1974 - TCP protocol invented by Vint Cerf • 1984 – On January 1, the Internet with its 1000 hosts converts en masse to using TCP/IP for its messaging • 1968 is really the “birth” of the Internet • 1984 is really the “high-school graduation” of the Internet
ARPANET is Born 1968 TCP/IP Created 1972 Internet Named TCP/IP Used 1984 Hypertext Invented 1965 WWW Created 1989 Packet Switching Invented 1964 Mosaic Created 1993 First Vast Computer Network Envisioned 1962 Age of eCommerce Begins 1995 1962 1995
Claude Shannon • The Father of Modern Information Theory • Created the idea that all information could be represented using 1s and 0s. Called these fundamental units BITS. • Won a Nobel prize for his master’s thesis in 1936 Source: http://www.research.att.com/~njas/doc/ces5.html
Vannevar Bush • Summary: Vannevar Bush established the U.S. military/university research partnership that later developed the ARPANET. • He also wrote the first visionary description of the potential use for information technology, inspiring many of the Internet's creators. Source: Livinginternet.com
Vinton Cerf • Summary: Vinton Cerf is co-designer (with Bob Kahn) of the TCP/IP networking protocol. • Worked for DARPA, projects include d • the Packet Radio Net (PRNET), and • the Packet Satellite Network (SATNET). Source: Livinginternet.com
Tim Berners-Lee • The inventor of HTML. • Now works for Laboratory for Computer Science (LCS)at the Massachusetts Institute of Technology (MIT). • Directs the W3 Consortium, an open forum of companies and organizations with the mission to realize the full potential of the Web. Source: w3c.org
The Internet vs. World Wide Web • What EXACTLY is the difference between the Internet and the World Wide Web? • Why is it important to know the difference?
The Internet • Computers can be connected in a variety of different ways. • Ethernet, Token-ring, Wireless, Ports (Serial, Parallel, USB). These are all communication subtrates. • Two or more connected computers form a Network • The CS Dept. has its own Ethernet Network • Different types of networks can be connected • via bridges, gateways, etc.
The Internet • Two or more connected networks can be called an inter-network • Inter-networks can obviously be connected • At some point in history, inter-networks became connected across the entire USA • Eventually, inter-networks became connected across the entire world • The entire world-wide collection of connected networks became known as The Internet.
The Internet Most experts in the “Network World” think of The Internet as both • The physical infrastructure (wires, routers, hubs, switches, satellites, optical cables, receivers, transmitters, etc.) that form the inter-connections. • And, the actual collection of computers (and devices) that are “inter-connected.”
The World Wide Web (WWW) • Most experts think of The WWW as • data that is accessible via a URL • (narrow definition) • All the data and services that are widely available via The Internet • (general definition)
The World Wide Web (WWW) • Thus, The Internet is the physical hardware that makes the connections possible and • The World Wide Web is the content and services that are widely available over this massive collection of connected computers. • Important Note: • Some companies use the Internet to share information, but this information is only accessible through proprietary protocols, • Since, it is NOT widely available, it is not really part of the WWW.
The World Wide Web (WWW) • While the two terms are somewhat synonymous to the non-expert, • You should be aware of the difference between The Internet and the WWW Internet WWW
The World Wide Web (WWW) Examples: Content & High-level Protocols • Content: WebPages • Hypertext Transfer Protocol (http) • URL (Universal Resource Locator) • Content: Data Files & Programs • File Transfer Protocol (ftp) • Content: Music & Videos • Gnutella Protocol
The World Wide Web (WWW) More examples • Content: Email • SMTP (Simple Mail Transport Protocol) • IMAP (Internet Message Access Protocol) • POP (Post-Office Protocol) • DNS (Domain Name System) • MIME (Multipurpose Internet Mail Extensions) • Content: Peer to Peer messaging • AOL IM Protocol • MSN Messenger Protocol
The Internet Examples: Hardware & Low-Level Protocols • Hardware • Computer, Ethernet card • Communication Substrate:CAT-5 cable, fiber optic cable • Router, Hub, Switch, Bridge, Gateway • Low-Level Protocols/ Concepts • TCP/IP (Transmission Control Protocol/Internet Protocol) • Packet Switching
Web Pages E-mail Mailing Lists Newsgroups (Usenet) Chat, IRC, AOL IM Search Engines FTP Telnet (SSH) Telephony Database Access Application Access E-Commerce Streaming Video/Audio Capabilities of the Internet & WWW
WWW Concepts • Authority • Vertical Portal or Vortal: A Web site that specializes in providing information related to a particular industry such as automobiles, healthcare, or investments. • Hub or Gateway • Horizontal Portal: Provides services and links to Web sites of interest to a wide variety of users.
WWW Concepts • Webcasting: The prearranged delivery, or push, of information of interest to a user’s desktop automatically. • Pull: • To get something from a Web site by clicking on a link or entering a URL. • Push: • The capability of a Web site for automatic Internet delivery of information, including software updates, to a user’s desktop.
The Internet Community • Internet Users • Internet Service Providers (ISPs) • Application Service Providers (ASPs): Companies that develop, install, and operate (or host) an information technology application • Content Providers: Individuals or companies that furnish the information available on the Internet.
The Internet Community • Internet Support Agencies • Internet Corp. for Assigned Names and Numbers (ICANN): The nonprofit corporation responsible for • the IP address space allocation • protocol parameter assignment • domain name system management, and • root server system management. • Internet Engineering Task Force (IETF): A large international community of network designers, operators, vendors, and researchers concerned with • the evolution of Internet architecture and • the smooth operation of the Internet.
URLs • Uniform Resource Locator • Human-readable WWW Address • Examples: • http://www.cs.siena.edu • ftp://ftp.cs.rpi.edu • ebreimer@siena.edu • Includes email addresses and newsgroups
URLs • Example: http://www.cs.siena.edu • http is the protocol • www is the host name (server name) • cs.siena.edu is the domain (network address) • edu is the top level domain • siena is essentially Siena College’s network • cs is the CS Dept Network (sub-set of Siena)
Internet Addresses • Domain Name System (DNS): Computers have numeric addresses consisting of strings of numbers known as their Internet protocol (or IP) address. • Domain Name: The familiar, easy-to-remember names for computers on the Internet that correlate to assigned IP addresses. • Uniform Resource Locator (URL): Like a Street Address for the WWW. • Registry: A regional organization that allocates Internet addresses to requestors in that region.
IP Addresses • Numeric Internet Address • Part of the TCP/IP Protocol • URLs are translated into IP Addresses by DNS Servers • DNS Domain Name System
IP Addresses • Example: 64.236.24.4 • 4 numbers separated by decimal points • 64 is the top level network • 4 is a specific computer (host or server) • Lets do an nslookup on an IP Address
Internet Addresses • Registrars: Organizations delegated to accept and process Internet address applications and submit approval applications to the regional registrar. • Root Servers: One of 13 special computers distributed around the world that maintain the Internet addresses for all global and country registries.
HTML • Hypertext Markup Language (HTML): • A set of commands that specifies the position, size, and color of text, the location of graphic information, and the incorporation of sound and video. • HTML commands also identify the words or images that will serve as hyperlinks to other documents.
Internet Growth Trends • 1977: 111 hosts on Internet • 1981: 213 hosts • 1983: 562 hosts • 1984: 1,000 hosts • 1986: 5,000 hosts • 1987: 10,000 hosts • 1989: 100,000 hosts • 1992: 1,000,000 hosts • 2001: 150 – 175 million hosts • 2002: over 200 million hosts • By 2010, about 80% of the planet will be on the Internet
Important Milestones September 2002 > 200,000,000 IP Hosts > 840,000,000 Users Netsizer.com – from Telcordia
Sept. 1, 2002 Dot-Com Bust Begins Chart by William F. Slater, III The Internet was not known as "The Internet" until January 1984, at which time there were 1000 hosts that were all converted over to using TCP/IP.
Internet’s Growth • To get a market of 50 Million People Participating: • Radio took 38 years • TV took 13 years • Once it was open to the General Public, The Internet made it to the 50 million person audience mark in just 4 years!
Web Servers • Rough map of the world as seen from our web server • Your web server is only as fast as your slowest network bottleneck. Siena College Roger Bacon Ken Swarner’s office www (ares)
Web Servers • How can I set up my own web server. • First, you need to get software • Second, you need a pretty good internet connection • Third, you need to register a domain name • Finally, you need to actually make some webpages • How much does this all cost? • How hard is it?
Web server software • Apache (its free and its very good) • UNIX and Windows versions • Problems: • Not super easy to setup or configure • If you are not already a nerd, you’ll probably need a lot of time. • Microsoft makes several different servers • Somewhat easier to setup than Apache
Internet connections • Dial-up $10-30/month • DSL $30-40/month • Cable $40-50/month
Internet connections • T1 • $250 to $1000/month • 1-3 Mbps • T3 • $3000 to $15,000/month • 3-45 Mbps
Internet connections • OC-3 • $20,000 to $50,000/month • 150+ Mbps • OC-12 • Over $500,000 year • 600+ Mbps • OC-48 • Good luck finding one • used internally by companies like Sprint who sell the above connections • 2400+ Mbps
Internet Connections • Siena used to have • 3 dedicated T-1 lines (bundled?) • about 3 Mbps • Siena now has • RoadRunner Premier (perhaps two separate connections) • about 6 Mbps (just a guess
Internet Connections • RPI (3 years ago) • Equivalent of 2 dedicated T-3’s • 50+ Mbps • 10-times Siena’s bandwidth. • Now, they may have an OC-3 • 150+Mbps • 30-times Siena’s bandwidth