The average person uses a computer network in almost every aspect of modern—day life, in developed countries. Many people take the use of these services for granted. Most of us, today, have instant access to services that can connect us to a worldwide variety of online goods and services instantly, from a wide range of devices.
The infrastructure for these networks is a product of advancements, which have taken place over the last thirty to forty years of computing and innovation. These innovations have come from research and development that has taken place in universities, the military, and commercial environments. The resulting technologies combined have resulted in one of the most amazing events in human history—the birth and growth of the Internet. From the simple beginnings of research and development projects in the 1960s, the Internet today connects a large percentage of the world’s population to online goods and services.
In these following sections, I will outline some of the key projects and technologies that have provided some of the foundational elements of today’s modern networks and the Internet. Each element provides some of the critical components that allow the widespread use of the Internet today.
If you look at the following timeline, I have outlined some of the major developments that have led to the widespread usage of the Internet today. Although there were many other significant developments, which occurred during this timeline, I have selected these primary technologies as key advances that allowed engineers to design the building blocks of today’s Internet.
The period from the 1960s until the early 2000s saw some incredible growth and innovation with respect to computer networking. The technologies, which were developed on a step by step basis, not only revolutionized computing, but changed the way in which we live our lives.
Michel Bakni, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons>
In the early 1960s, several groups researched packet switching as a way to allow computers to communicate with each other. Until that time, circuit switching had been the method for computer communications. Through the work of several research groups at MIT, the Rand Institute, and the National Physical Laboratory in England, they developed some of the basic concepts that the Internet uses today.
The block message, pictured above, was suggested by Paul Baran in 1964, and published during his initial research on Packet Switching. This concept was later referred to as a packet and was incorporated in initial designs of the ARPANET. This design was a radical departure from using dedicated circuits and expensive hardware. The concept was met with a large amount of scepticism, from the engineering community, at that time.
ARPANET, Public domain, via Wikimedia Commons
In the late 1970s, work that was sponsored by the Defense Advanced Research Project Agency, or DARPA, developed a network of computers called ARPANET. This effort developed a method for different computers to communicate with each other. This research included computers from both military installations and research universities. In the early 1980s, the project grew from an initial handful of machines, to hundreds. The structure and growth of the ARPANET provided the basic model for our current Internet.
Pictured above is a map of the ARPANET computers from March 1977. At that time, this was a state-of-the-art network, and it was growing rapidly. The ARPANET continued to be used for research and development until it was decommissioned in 1990.
The underlying protocol the Internet uses today, for network traffic, is called TCP/IP. It stands for Transmission Control Protocol/Internet Protocol. While working for the Defense Advanced Research Project Agency, two scientists, Vint Cerf and Bob Kahn, developed TCP/IP. They migrated the ARPA network to this protocol and eventually migrated the entire system in 1983. TCP/IP eventually became the standard for all military networks. Following this success, they published their work in the Request for Comments (RFC) standards. This allowed TCP/IP to move into the public domain. This work provided the basis for the networking standards we still use today.
The figure displayed below is the basic architecture of TCP IP. It is a layered architecture that allows for the flexibility of this protocol. The design of this protocol has been so successful that it has been in widespread use on the Internet since the 1990s.
World Wide Web (WWW)
Paul Clarke, CC BY-SA 4.0 https://creativecommons.org/licenses/by-sa/4.0, via Wikimedia Commons
Tim Berners-Lee, (pictured above) who worked at CERN, the European Organization for Nuclear Research, invented the World Wide Web, or WWW, in the 1989-1990 time frame. CERN and Tim Berners-Lee developed the first web server. This was driven by the need for researchers around the world to share information. After the first web server was developed, CERN published instructions on how other institutions could set up their own web servers. These instructions resulted in several hundred other institutions hosting their own web servers. In 1993, CERN opened the code, for the web servers and the browser, to the public domain, making the software freely available. Once the software was in the public domain, it provided the basis for the explosive growth of the World Wide Web, followed by the Internet.
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