E-mail Part 2
A Brief History of the Internet
Tutorial Overview
Topics covered in this tutorial (click link to jump to topic):
It’s the cold war and the US government had a problem; if we have a nuclear war how are we going to maintain communications? If one city is destroyed on the US eastern seaboard, all communications in the east will be lost. A US military agency called Advanced Research Projects Agency (ARPA) was charged with solving the problem. They devised a communication system that would still work if one or more "nodes" of the system were destroyed. A kind of communications web, that if one link of the web was broken, information could flow around the broken link to get to its final destination. Later, in 1969, ARPA linked university computers and researchers to the network to assist them in conducting basic research through information sharing. This project became known as the ARPAnet. In 1977 ARPAnet engineers realized that the new communications network was going to grow into something much larger than originally anticipated so new communication technology would be required. They devised a communication protocol known as TCP/IP, or transmission control protocol/internet protocol. TCP/IP remains the fundamental way computer file are moved around the Internet today. Under TCP/IP a file is broken into smaller parts called "packets" by the file server. Each packet is assigned an IP (Internet protocol) address of the computer it has to travel to. As the packet moves through the network it is "switched" by a number of servers along the way toward its destination. The IP address tells those servers which way to switch the packet. Each time the packet is switched a "wrapper" is added to the packet – this way we can tell how many computers and which computer handled the file while it was in transit. In Australia, a file coming from the States can be switched up to 15 times, that is fifteen computers were required to deliver the packet to the destination computer. The packets do not necessarily travel together on the Internet. Packets from the same file may travel via different paths through different servers, but toward the same destination. Packaging technology allows us to use limited bandwidth most efficiently. It means parts of a file can be shared across a number of phone lines instead of having to find one phone line to put a large file into. In this respect TCP/IP can be liken to a group of 10 hitchhikers (packets) who can not get a lift all together, but easily get lifts if they break up, going by different cars and maybe by different roads… but agree to meet up at a particular point in the future. On January 1, 1983, all of the ARPAnet was switched to TCP/IP and became what is now known as the Internet. The US National Science Foundation (NSF) funded most of the early development of the Internet, but on April 30, 1995, the U.S. government released the Internet to commercial networks and service providers and shut down the old National Science Foundation backbone. In March 1989, Tim Berners-Lee (see Amazon book recommendation below) at the European Laboratory for Particle Physics (CERN) proposed a new set of protocols for Internet information distribution. They were; http (hyper text transfer protocol), ftp (file transfer protocol), pop (post office protocol), smtp (simple mail transfer protocol) and nntp (newsgroups protocol). These five protocols became known as the World Wide Web protocols and the W3 protocols and were soon adopted by the early Internet community. A consortium of organizations was formed to oversee Internet development and became known as the W3 Consortium. No organisation or individual owns the Internet. Before the World Wide Web, the Internet consisted mostly of electronic mail (e-mail), newsgroups and ftp. Tools were invented to help categorize what information could be found and where it was, but the Internet was not what you would call "user friendly". If you needed a particular computer program or file, it was nearly impossible to find unless you knew exactly where it was. Today however, we have specific software to address each of the W3 protocols. We have "browsers" to help us locate and look at web pages. We have e-mail clients to help us create, send and receive e-mail. We have newsreaders just to read news, FTP clients just to download program files and chat clients to help us do Internet Rely Chat. Today you don’t have to be a rocket scientist to work out where to find information and what to do when you get there.
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24-May-2008
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