The Internet as a Cold War Child
Why was Internet routing invented? Understanding this is key to understanding the basic facts about TCP/IP, the Internet, networking and the 'big picture'.
The Internet had its origins in a project called ARPANET which was started in 1968. It evolved to become the Internet during the subsequent decades. At the outset, the main sponsor was the US Department of Defence.
ARPANET was a child of the Cold War. The problem it was trying to solve was that of the effect of a nuclear attack on the USA. Any communications network would obviously be a priority target in such an attack, and so if there was a ‘central switchboard' facility it would only have to be targeted to take out communications all over the USA.
The Defence planners were acutely conscious of the strategic risk presented by a central communications facility. So 'Routing' and ‘Packet Switching' were devised to meet this challenge.
In a packet-switched network, messages are divided into ‘packets' and individually sent with their destination attached - rather like the address on an envelope. Each data packet contains part of the complete message and the 'routing' information that will enable it to reach its intended destination. As well as this, it contains the code which informs the receiver which message it is part of, along with code which enables the receiver to know if it has all been transmitted successfully. In the event that either (1) part of the route to the destination becomes blocked, or (2) part of the message is lost, the system will either re-route the data or re-send the missing components, or both.
When the data packets arrive at their destination, they are re-assembled to deliver the original message content. And this all happens in an instant.
This complex sequence of events is controlled by TCP/IP which stands for Transmission Control Protocol/Internet Protocol. This is the underlying technology behind the Internet and most current PC networking. You could say that it is to the information age what electricity was to the industrial revolution. It is an amazing technical achievement and one of the great inventions of the 20th century.
An important point is that TCP/IP was not invented for consumer convenience. It was designed as a military technology, by scientists with advanced degrees in mathematics and computer science. Now you're using it to go shopping and look up the train timetable. Hey, that's life, nowadays. So while some might complain that using the Internet ought to be as easy as making toast, this article assumes that it never will be, and encourages you to learn more about how it works. And no, this doesn't mean getting a degree in computer science, because you will probably never have to understand it that deeply. But getting an idea of how TCP/IP works is essential.
Below, two of the inventors of TCP/IP, Vince Cerf (left) and Bob Kahn, with President Bill Clinton, at an award ceremony recognising their contribution to the creation of the Internet.
