Evolution of The Internet The structure and makeup of the Internet has adapted as the needs of the community have changed. Today's Internet serves the largest and most diverse community of network users in the computing world. Since it was created, the Internet has grown in size and become something that the entire world is almost completely dependent on. The Internet started as an experiment in the late 1960s by the Advanced Research Projects Agency of the U.
S. Department of Defense. It was originally developed to explore the possibility of a communication network where there would be no obvious central command, but all surviving points would be able to re-establish contact in the event of a nuclear attack. It continued simply because the Department of Defense, its contractors, found that it provided a convenient way to communicate. For the first decade the Internet was in existence, its primary use was to facilitate e-mail, support on-line discussion groups, allow access to distant databases, and support the transfer of files between government agencies, companies, and universities(Cerf 286).
In December 1969, the experimental network went on-line with the connection of a four-node network connected via 56 Kbps circuits. This new technology, known as ARPANET, proved to be highly reliable and led to the creation of two similar military networks, MILNET in the U.S. and MINET in Europe. Thousands of hosts and users connected their private networks to the ARPANET, thus creating the initial "ARPA Internet". The problem with ARPANET is that it had an Acceptable Use Policy, which prohibited the use of the Internet for commercial use(The ARPANET and Computer Networks 143).
By 1985, the ARPANET was heavily used and congested. In response the National Science Foundation began development of the NSFNET. The NSFNET was made up of multiple regional networks and peer networks connected to a major backbone that held the entire network together. In its earliest form in 1986, the NSFNET created a three section network architecture.
The architecture connected campuses and research organizations to regional networks. These connected to the main backbone which linked six super-computer centers(Alexander 11). The NSFNET backbone connected thirteen sites and five NSF supercomputer centers. In 1991, data traffic had increased tremendously, which caused the upgrading of the NSFNET's backbone network service .
These new connections were over one hundred times faster than the original connections and much more dependable due to the implementation of two new protocols for the computers to communicate with called Transmission Control Protocol and Internet Protocol, commonly referred to as TCP/IP (Anderson 1064-65). As late as the early 1990s, the NSFNET was still reserved for research and educational applications; and government agency backbones were reserved for mission-oriented purposes. But new pressures were being felt by the networks, different agencies needed to interconnect with one another. The nation was urning for network access, and Internet service providers were emerging to accommodate those interests, defining a new industry in the process. Networks in places other than the U.
S. had developed, along with interest in international connections. As the many new networks pursued their goals, the complexity of connections and the Internet's internal structure grew(Applications of Information Network 57). Government agency networks connected at Federal Internet Exchange points on both the east and west coasts. Commercial network organizations had formed the Commercial Internet Exchange association, which built an interconnect point on the west coast. At the same time, Internet service providers around the world had developed substantial infrastructures and connectivity.
To begin sorting out the growing confusion, Sprint was appointed by NSFNET to be the International Connections Manager to provide connectivity between the American, European, and Asian networks. NSFNET was decommissioned in April 1995(The Evolution of Packet Switching 266-7). The shutdown of the NSFNET had to be done in specific stages to ensure continuous connectivity to various institutions and government agencies that used to be connected to the regional networks. Today's Internet structure has changed from a core network, such as NSFNET, to a more distributed architecture operated by commercial providers connected via major network exchange points. This "new" Internet is a collection of providers that have connection points called points of presence over multiple areas. Its collection of points and the way its points are interconnected form a providers network.
Customers are connected to providers via the points of presence. Customers of the providers can be providers themselves, and these providers using points of presence thoughout the U.S. are known as national providers which are commonly referred to as network service providers(Heart, et al.
46-48). This network started out with a small four node experiment and grew into the single largest machine the world has ever known. Information can be sent between almost any two points on the globe. This "Information- Superhighway" is one of the greatest achievements mankind has ever seen, and will continue to shape the world and adapt to the new world that it has created.
