Internet

Slide 1:Internet 8th Grade Technology January 2006

Slide 2:What is Internet? It is a global collection of networks, both big and small. These networks connect together in many different ways form the single entity that we know as the Internet. The very name comes from this idea of INTERconnected NETworks.

Slide 3:Internet History In the late 1960s the American computer scientist Robert E. Taylor at the Advanced Research Projects Agency (ARPA), later called the Defense Advanced Research Projects Agency (DARPA), of the U.S. Department of Defense began to look for ways to connect the different technologies of COMPUTER, networks. Led by the American networking pioneer Leonard Kleinrock, DARPA sponsored an experiment in 1969, based on the packet-switching principles he had developed, in which computers at the University of California campuses at Los Angeles and Santa Barbara, the University of Utah, and Stanford Research International (a nonprofit scientific research institute) successfully communicated with each other. Thus began ARPANET, the first internetwork, or system of interconnected networks. In 1972, ARPANET was expanded from 4 to 50 networks, connecting universities and research organizations with specialized military networks.

Slide 4:Internet History In the late 1970s, UNIX to UNIX CoPy (UUCP), a communications network based on the UNIX operating system, and Users Network (USENET), serving the academic community and, later, commercial organizations. More structured networks, such as the Computer Science Network (CSNET) and Because It's Time (BITNET), provided nationwide networking to universities and research centers. In the early 1980s ARPANET split into two networks, ARPANET and Milnet (an unclassified military network), the two networks were still interconnected. Access to ARPANET was originally restricted to the military, defense contractors, and institutions doing defense research. By 1986, ARPANET had links to all major universities and research facilities, and satellite links to several international locations. That year, the National Science Foundation (NSF) created a network, NSFNET, to connect SUPERCOMPUTER, sites around the U.S., as well as research institutes and schools located near the supercomputers.

Slide 5:Internet History NSFNET had entirely replaced ARPANET, which was officially dismantled in 1990. NSFNET became the central network, or backbone, of the Internet in the U.S. In 1991, then U.S. Senator Al Gore proposed expanding the architecture of NSFNET to form the National Research and Education Network, the so-called Information Superhighway, which would include more elementary and high schools and community colleges. The resulting High Performance Computing Act also allowed business networks to connect to the Internet for commercial uses, causing an explosion in its growth. NSFNET was discontinued in 1995 and by the end of 1996 large commercial networks had taken over as the high-speed central networks of the Internet.

Slide 6:Who is the owner of Internet? Nobody owns the Internet, but it doesn't mean it is not monitored and maintained in different ways. The Internet Society, a non-profit group established in 1992, oversees the formation of the policies and protocols that define how we use and interact with the Internet.

Slide 7:How Internet works?

Slide 8:How Internet Works? TCP/IP IP Address ISP Domain Name

Slide 9:TCP/IP Transmission Control Protocol / Internet Protocol (TCP/IP) Protocols are rules or standards, that allow unlike computers communicate with other computers on Internet. Developed by the American computer scientists and Internet pioneers Vinton G. Cerf and Robert E. Kahn at Stanford University. In 1974 they were announced as a common, or open, standard; that is, they are not proprietary, or exclusive, to any one manufacturer.

Slide 10:TCP/IP It has been the Internet protocol since 1983. When you send information over the Internet, the TCP/IP prepares the data to be sent and received. The information is configured so that different networks can exchanged information with one-another.

Slide 11:TCP/IP TCP initiates the transmission of a data file and connects to the destination address to ensure end-to-end transmission. IP then breaks the file into packets of information--small enough to travel over the network. Each packet is coded with the data's correct sequence in the complete file, as well as with the binary addresses of the sending and receiving computers. To maximize transmission speed, TCP/IP permits each packet to travel independently over many different networks to the receiving computer. The flow of packets across the Internet is directed by computer equipment called routers. Each router contains software that reads a packet's IP address, checks the information, and sends the packet along cables or other media equipment on the most efficient path to the next router.

Slide 12:TCP/IP The packet-switching process is repeated until the packet reaches its final destination. Along the way, packets may pass through gateways, which are internetworking devices that translate protocols between unlike networks and allow TCP/IP packets to pass through any system on the route. After all the packets arrive at the receiving computer, IP reads the sequence code and reassembles the data into the order of the original file. TCP controls the transmission by verifying the sequence and retransmitting a packet if necessary. TCP/IP is invisible to the user, and the entire send/receive/verify process takes less than a second to complete.

Slide 13:IP Address For the system to work, every location (machine, router, name server, hosting account, etc.) on the internet must have a unique IP address (a set of numbers like 216.27.61.137 or 11011000.00011011.00111101.10001001). The IP address function just like street addresses for the internet. These addresses represent the exact location of a particular site on the internet, and serve to guide any other user to that location.

Slide 14:IP Address It is impractical to ask people to remember the number; however, the domain name is associated with this particular IP address and is easy to remember. When a user types the domain name into a web browser, the internet Servers (large computers at the Internet Service Provider (ISP) of the user) serve as translators. The name servers look up the domain name and resolves it into the IP address which it refers to. The system is designed so that the user does not even notice that the translation occurs.

Slide 15:Local ISP in Tampico Telmex Prodigy 33 kbps or more Infinitum 256 kbps, 512 kbps or 2 mbps Terra Premium for unlimited time Pre-pago for 750 minutes AOL Interxcable

Slide 16:Domain Name When you use the Web or send an e-mail message, you use a domain name to do it. For example, the Uniform Resource Locator (URL) "http://www.howstuffworks.com" contains the domain name howstuffworks.com. Every time you use a domain name, you use the Internet's DNS servers to translate the human-readable domain name into the machine-readable IP address.

Slide 17:DNS The domain name and its associated IP address are first listed on the hosting organizations Domain Name Server (DNS). Then this information is propagated over the course of a few days until the domain name is listed in EVERY name server. The way this operates is similar to having your name and corresponding phone number listed in every phonebook in the world.

Slide 18:Most Familiar Domains com commercial organization, business, or company edu� educational institution int international organization gov� nonmilitary government organization mil������ military organization net������ network administration org������ other nonprofit, nonacademic, ��������������� nongovernmental organization

Slide 19:Bibliography Internet Society. "A Brief History of the Internet and Related Networks." Internet Society. 2005. http://www.isoc.org/internet/history/cerf.shtml (27 Nov. 2005). Rhonda Davila. "History and Development of the Internet." San Antonio Public Library. 2000. http://www.sat.lib.tx.us/Displays/itintro.htm (27 Nov. 2005). OPB Learning Media. �Timeline." Nerds 2.0.1. 1998. http://www.pbs.org/opb/nerds2.0.1/timeline/ (27 Nov. 2005).