The Structure of the Internet

1. The Structure of the Internet ARPAnet ARPAnet was founded in 1969 as a method for computers to communicate over long distances. At that time it was designed for research purposes hence its name Advanced Research Project Agency Network It allowed computers connected together to work on projects simultaneously without having to keep calling each other. At this point it only consisted of 4 computers : Stanford Research Institute, UCLA, UC Santa Barbara, and the University of Utah. Growth After it was first set up many academic groups found it could become a useful tool for research and academic projects. Many universities and government research groups started to link into it and soon it had grown into a large network. In just two years it had grown to 23 computers. And only 4 years after it was established it went international by providing links to the University College of London. At this point the network started to grow away from a purely research based network, already e-mail was the most used application, allowing users to talk about projects, current topics, and just any subjects that interested them. Not long after this in 1974 a commercial version was produced, and gave hints that eventually this could be used by most people. In 1979 the first Usenet groups were produced as an answer to mass e-mail problems. And allowed many users to talk about subjects with new people. In 1981 ARPAnet consisted of 213 hosts, with another being added every 20 days. In 1990 ARPAnet was forced to close down, leaving only the network of networks with no central system. At this point it consisted of more than 300 000 systems. By 1997 this number had grown to over 1.7 Million computers, and is growing exponentially at this point. Connecting Since the internet was first formed many new connection formats have been introduced, these allow people to connect through different systems without always needing expensive technology. The most common of these is the Dialup Modem, and allows people to connect to the internet by using a regular phone line to call up a company or connection group who then provide a connection to the network for you. For this purpose Internet Service Providers or ISP's were formed. These provided a connection to the internet for a cost per month or annually, and now provide several other common products such as an E-Mail account, Webspace for a webpage, and will almost always provide the software needed to connect to them. Protocol When the internet was first formed there was not a problem with the ‘language’ computers used to communicate, however when the network continued to grow, and new usage's discovered and added, people needed a standard ‘language’ to allow them to work without causing a lot of problems. To allow this a Standard group of standards were formed, the first of these was 1983 with TCP allowing computers to connect to each other and talk easily. In 1984 a Domain Name System was introduced, allowing computers to recognise each other by a name rather than a number in 1997 the HTTP protocol was introduced, and became the most used standard for data transfer