A Brief History of the Internet's Origins - First Steps

A Brief History of the Internet's Origins - First Steps

The Internet has evolved constantly from the time that US universities first connected using 56 kilobyte connections and began sending electronic messages. In the late 1950s US computer researchers were looking for a way to connect the computers at American universities which were often separated by hundreds or thousands of miles. Many felt that a new idea, packet switching, was vastly superior to standard telephone voice circuits. Packet switching was a better fit for time sharing computers and offered a way to interleave data from many users into a single data stream. Using a dedicated telephony circuit for each application data stream was highly inefficient. 

In the early 60s J.C.R. Licklider at MIT proposed the idea of a 'Galactic Network'. This global network would allow any connected computer to send and receive data. Every user could access data and programs from any connected site. Licklider eventually became head of the computer research program at DARPA. He not only was an effective evangelist, but his disciples went on to run the computer research program for the next 20 years ensuring that the 'Galactic Network' we call the Internet would become a reality.

At the same time in the early 60s the first papers and books on packet switching were published. Packet switching offered the first alternative to dedicated circuits. Key to packet switching is that it is asynchronous and does not required dedicated resources be reserved for any particular user application. This was important because the best way to use big computers involved time sharing. So it was important to have a network technology that could mix together traffic from different users and send it to the far side where it could be separated and delivered to the individual users. If the mainframe is effectively multitasking, then a telephone circuit is totally awkward because it would have to be set up and torn down constantly for each distinct, often small data flow.

By the late 60s, an academic consensus was reached that any network for computers must be packet switched. Hence an RFP was launched for the first packet switching routers that was won by BBN. These early packet switches were known as message interface processors. This reflected the fact that email was a prime motivation. 😀 Along with the idea that packet switching was more inefficient, there was also the idea that packet switching must allow computers to talk back and forth as opposed to being just one way data flows. Errors are always possible and it was necessary to ways for the receiving computer to acknowledge it had received a packet and that it was error free. 

By late 1969, the Arpanet was launched with a computer host at each of four universities connected via a wide area network. The first functionally complete network protocol was known as Network Control Protocol or NCP. One thing that researchers realized that in order for the Arpanet to scale it must use a protocol that was technology agnostic. Whether it was frame relay, ATM or Ethernet or some other network technology, the Arpanet protocol must be technology agnostic and not require any specific knowledge of the packet switching technology. 

In October, 1972 there was a large scale and very successful public demonstration of the Arpanet at the International Computer Communication Conference. It was followed shortly by the launch of the first practical email program. Email was the dominant application until the 1980s.