The Internet Dr. Irwan Sembiring, ST.,M.KOm

The ARPAnet The predecessor to the modern Internet.

The Internet 3  ARPAnet is the predecessor to the modern Internet. Originally, provided the exchange of electronic mail coded as standard ASCII text messages. Each message was small (1-10K) - one page.  1969 Experimental prototype developed by DOD. The First Internet backbone (1969)

The Internet 4  26 computers hooked up to the ARPANET by 1971; around 1,000 computers by  Now a large, growing, connection of over 10,000 networks and 30+ million users in over 60 countries.  NUA Survey: million on-line as of February 2002.

The Internet Network connecting other networks

The Federal Networking Council  On October 24, 1995, the FNC unanimously passed a resolution defining the term Internet. This definition was developed in consultation with the leadership of the Internet and Intellectual Property Rights (IPR) Communities.  RESOLUTION: "The Federal Networking Council (FNC) agrees that the following language reflects our definition of the term "Internet". "Internet" refers to the global information system that –  is logically linked together by a globally unique address space based on the Internet Protocol (IP) or its subsequent extensions/follow-ons;  is able to support communications using the Transmission Control Protocol/Internet Protocol (TCP/IP) suite or its subsequent extensions/follow-ups and/or other IP-compatible protocols; and  provides, uses or makes accessible, either publicly or privately, high level services layered on the communications and related infrastructure described herein."  A shared infrastructure, owned by no one: Much like the railway network, no one company owns it. The Internet 6

 “Internet” refers to the global information system that –  is logically linked together by a globally unique address space based on the Internet Protocol (IP) or its subsequent extensions/follow-ups.  is able to support communications using the Transmission Control Protocol/Internet Protocol (TCP/IP) suite or it subsequent extensions/follow-ons, and/or other IP- compatible protocols, and  Provides, uses or makes accessible, either publicly or privately, high level services layered on the communications and related infrastructure described herein. The Internet 7 Haviland & Barnes, The Digital Lexicon, 2002

Development of the Internet 1956USSR launches Sputnik, 1st satellite; USA Department of Defense (DOD) forms Advanced Research Projects Agency (ARPA) 1962Packet-switched network concept 1969DOD starts ARPANET for networking research 1974Protocol for packet internetworking Transmission Control Program (TCP) 1981BITNET (Because Its Time Network) provided widespread access. Minitel is deployed across France by French Telecom 1982Internet Protocol (IP) established TCP/IP 1984Domain Name Server (DNS) introduced and number of host is 1,000 The Internet 8

1986NSFNET created a high speed backbone (56Kbps) to interconnect supercomputer centers 1987Number of hosts breaks 10, Number of hosts breaks 100,000 and NSFNET is upgraded to T1 line (1.544 Mbps) Commercial carrier (Compuserve) connects to the Internet 1990ARPANET ceases to exist; MCI mail connects to the Internet 1991WAIS released by Thinking Machines Corporation to aid information search Gopher released by U of Minnesota The Internet 9

1992WWW released by CERN (a physics research institute in Switzerland) Number of hosts breaks 1,000,000 NSFNET upgraded to T3 line ( Mbps) 1993WWW annual growth rate 341,634% Whitehouse goes online United Nations & World Bank go on-line. US National Infrastructure Act championed by Al Gore. Mosaic developed by National Supercomputer Center The Internet 10

1994Netscape Communities become wired to the Internet For example, Blacksburg, VA - bus & movie schedules on-line, town meetings, etc. US Senate and House go on-line Mass marketing frenzy on the Internet USA sales at cybermalls grows to $200 million versus $50 billion in catalog sales & $1.5 trillion in total USA retail sales. 1995*.com sites exceed *.edu sites 1996Electronic commerce gets going seriously 1998The government uses the Internet for public dissemination of information (or political assassination ) by publishing Starr’s report on the Internet. The Internet 11

How Many Online? The Internet 12 As of February 2002

TCP/IP TCP/IP ensures that messages are properly routed from sender to receiver and that these messages arrive intact.

 The Internet architecture is based on the standard TCP/IP protocol, designed to connect any two networks which may be very different in internal hardware, software, and technical design.TCP/IP  Once two networks are interconnected, communication with TCP/IP is enabled end- to-end, so that any node on the Internet has the ability to communicate with any other no matter where they are.end- to-end  This openness of design has enabled the Internet architecture to grow to a global scale. The Internet 14

Packet Switching The Internet 15 TCP = TRANSMISSION CONTROL PROTOCOL (Breaks messages into packets and reassembles them) IP = INTERNET PROTOCOL (Moves packets around the Internet) SOURCE: J. DECEMBER

 Packet switching is “first come-first served”  It allows efficient sharing of expensive lines as senders take turns transmitting packets  Since TCP/IP is “connectionless”, each packet is routed independently  Each packet can take a different route!  When congested, routers drop packets The Internet 16

 TCP/IP supports packet switching  This ensures reliable communication despite the chaotic traffic flow on the net  The data flow is broken up into ~200 byte packets which share the pipe, even though they originate in different sources  Routers send them along the pipes that have the lowest traffic flow at a given point in time  Routing algorithms are used to calculate traffic flow The Internet 17

Internet Protocol (IP) address

 Each computer on the Internet has a unique numerical address, called an Internet Protocol (IP) address, used to route packets to it across the Internet. (analogy: your postal address enables the postal system to send mail to your house from anywhere around the world)Internet  The IP address gives the Internet routing protocols the unique information they need to route packets of information to your desktop from anywhere across the Internet.routingpackets  If a machine needs to contact another by a domain name, it first looks up the corresponding IP address with the domain name service. The IP address is the geographical descriptor of the virtual world, and the addresses of both source and destination systems are stored in the header of every packet that flows across the Internet.domain namedomain name service The Internet 19

Domain Name System (DNS)

 The Domain Name System (DNS) consists of a network of servers that map Internet domain names like to a local IP addresses.InternetIP addresses  The DNS enables domain names to stay constant while the underlying network topology and IP addresses change.  This provides stability at the application level while enabling network applications to find and communicate with each other using the Internet protocol no matter how the underlying physical network changes.Internet protocol The Internet 21

Internet Network Topology

How we connect  We access the Internet from home through an Internet service provider (ISP). An ISP connects to a regional network that is connected to a national network.  At the office, a desktop computer might be connected to a local area network with a company connection to a corporate Intranet connected to several national Internet service providers.  In general, small local Internet service providers connect to medium-sized regional networks which connect to large national networks, which then connect to very large bandwidth networks on the Internet backbone. backbone The Internet 23

Backbones  Backbones, owned by large ISPs and telecom companies, are made up of:  MCI, Sprint, Qwest, IBM, ATT, ANS, etc.  High-speed TCP/IP routers in a number of cities connected by...  High-speed data lines leased from long-distance exchange carriers...  Forming national “backbones” connecting those cities The Internet 24 Source: Howard Rosenbaum

 Backbone providers sell access to individuals and companies within each backbone city  Traffic between cities moves over the leased- lines of the backbone  Leased lines are purchased from different long- distance companies for each city  Some providers lease several lines from different carriers to connect two cities  If one carrier has a problem and the link is lost, a connection through the other carrier is used to maintaining the backbone. The Internet 25

 Currently, backbones are generally 45 Mbps DS-3 or faster leased lines  A backbone operator may link a half dozen or a dozen major metropolitan areas using DS-3 lines  They also extend dozens or even hundreds of less expensive Mbps T-1 or DS-1 lines to surrounding communities from the major backbone cities  They extend from those points with yet less expensive 56 Kbps leased lines The Internet 26

Internet Exchange Points  The communications traffic on the Internet backbone is exchanged at large Internet Exchange Points (IXP), sometimes called Network Access Points (NAP) or Metropolitan Area Exchanges (MAE), constituting the top level of the Internet network topology.  The first five large NAP's in North America were established in the 1990's in Chicago, New Jersey, San Francisco, San Jose, and Washington, D.C. The Internet 27