Technology - The Internet Past, Present and Future
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THE INTERNET: Past, Present and Future 1.What is the Internet The Internet is: a network of computer networks which use the same protocol (TCP/IP),a peer-to-peer network - all connected computers are equal, used by more than 40 million people from about 100 countries, a cheap, fast and efficient way to access/exchange information. 2. History of the Internet - When and How Initiative of the US Dept. of Defence in the late 60s. Objective - create a decentralized, blast proof network which will resist a nuclear attack. 1969: Pentagon's Advanced Research Project Agency Network (ARPANET) was born. 1970-1972: 32 computers were connected to the ARPANET based on the NCP (Network Control Protocol) standard. E-mail was one of the first applications. 1974: Vinton Cerf and Robert Kahn published the first specification of the TCP (Transmission Control Protocol) to IEEE Transactions on Communications. 1982: TCP/IP replaced NCP on all ARPANET computers. About 10,000 computers on ARPANET by end of 1983. 1982-1989: Many US universities and Research Labs connected to the ARPANET Free software was developed and provided to Universities. 1986:National Science Foundation Net (NSFNet) was created as the backbone of the Internet. 1989:The World Wide Web was created by Tim Berners- Lee and Robert Cailliau of CERN (European Laboratory for Particle Physic). In the early 90s, NCSA (National Centre for Supercomputing Applications) University of Illinois at UrbanaChampagn developed Mosaic. Early 1990s:The Internet became global and commercial. Private Telecom operators provided bandwidth. Today more than 60,000 networks, 110 countries, 40 million users are connected. E-mail remains the most used application. 3. How the Internet Works Routing The Internet is a network of networks and data is sent from one network to the next by a special device called a router: A router is responsible for forwarding data from a computer towards the destination computers. One router connects to another router using data networks or leased lines and both are responsible for connecting two or more networks. The data could be an email message or the home page of a popular Web site. The process of sending data from the source computer to a destination computer is referred to as routing. For data to reach its destination, it can pass through several routers in different networks which could be in different countries. Domain Name Service Computers on the Internet belong to a certain hierarchy. At the highest level, this hierarchy is referred to as Top Level Domain (TLD). com, edu, nl, ch, fr, de, cz are examples of TLDs. Each computer has a unique name (www.spt.cz) and address (184.108.40.206). The assignment of both the names and the ad- dresses are based on a strict set of rules. When you connect to the Web server www.spt.cz, a special software translates the name to the unique address 220.127.116.11.The software is called the Domain Name Service (DNS).The rightmost part of the name (cz for www.spt.cz) signifies the Top Level Domain. TCP/IP The Internet is based on a family of protocols called TCP/IP - Transmission Control Protocol/Internet Protocol. Each protocol is responsible for a specific task. File Transfer -The File Transfer protocol allows a user on one computer to get files from another computer. Computer Mail -Allows you to send messages to users on other computers. Remote Login -Allows a user from one computer to log in to another computer. World Wide Web -Allows you to access hypertext information from a server. Many of the protocols are implemented as client/server models of network services. The client software requests services from the server software. The term "server" normally refers to the server software. World Wide Web Developed by TBL of CERN, the World Wide Web (based on HTTP – Hyper Text Transport Protocol) is one of the most popular applications on the Internet. The Web is based on the client/server model. The client (Netscape, Explorer, Mosaic) establishes a connection to a server via a URL (Uniform Resource Locator). A URL is a naming scheme for specifying how and where to find information from Internet servers such as Web, Gopher and FTP. The general form of a URL is: protocol: //host-name:port/directory/filename. The server accepts the connection and sends the requested information back to the client. The server then closes the connection. The data stored on the Web server is normally in HTML – Hyper Text Markup Language. Internet Today Problems The rapid growth and interest has introduced or amplified many problems: Security concerns for commercial applications, Bandwidth and server saturation, -Demand for faster access to multimedia data, Not enough IP addresses to meet the demands, Controlling access to certain types of data, -Protecting the work of authors - copyright issues. Factors Affecting Growth It is estimated that the Internet doubles in size every I I months and the World Wide Web doubles every 53 days. Commercial use of the Internet for Sales, Advertising and Marketing is being considered by most companies. Newer applications, cheaper and faster computers and modems, and connections via cable TV lines are bringing Internet connectivity to households. The planned introduction of the Network Computer (NC) by major manufacturers and the wide range of information available are also contributing to the growth and interest.