Origins of the internet

How it started

How it worked

The very beginning of the Internet can be traced back to the late 1960s, when the American Defence Department set up the ARPA (Advanced Research Projects Agency) to improve the telephone, radio and satellite communications systems for the US military. The result was the creation of the ARPAnet. However, on the whole, the military-oriented research did not influence the development of the Internet so much, this is an historical distortion that has been circulated by the media.

Many researchers worked on the project: one of them was Paul Baran of Rand Corporation who was studying how to build a communication network that would resist a nuclear attack. However, this was not the specific goal of the ARPA, but only one of the side products derived from the project. Paul Baran's study and a famous article he published in 1963 called "On Distributed Communication Networks", inspired the first practical result of a digital network connecting some American universities, and for years the net remained mostly the domain of the academic world.

As more computers were added, researchers - including Vincent Cerf and Bob Kahn, the two recognised forefathers of the Internet - had to think of an effective network architecture. What they did was the invention of the transmission protocols that make the net run.The solution was quite simple: a number of nodes (actually computers) spread out over an area, with each node having its own authority to originate, pass and receive messages. The messages would be broken down into packets, each one of them separately labelled and addressed.
The routes followed by the packets would be different and randomly chosen, although more or less in the same direction of their intended destination.
Very much like writing a letter, tearing it up into tiny bits and throwing it towards somebody that would pass them to somebody else, and then to somebody else still and so on till it reached its target.

The system was designed in such a way that sooner or later all the packets would have been pieced together at the destination node.