A Brief History of the Internet

A Brief History of the Internet – Leiner et al. 2003.

The above link is to an HTML version. There’s a pdf available on the ACM Digital Library too if you have access.

This paper was written to give “a factual rendering of the events and activities associated with the development of the early Internet,” from the key people involved in its design and development. It’s a great read to hear them tell the story in their own words.

Before there was the internet, there was… the Galactic Network! I guess when inter-networking across galaxies proved a bit ambitious, the ideas were brought back down to earth ;).

The first recorded description of the social interactions that could be enabled through networking was a series of memos written by J.C.R. Licklider of MIT in August 1962 discussing his “Galactic Network” concept. He envisioned a globally interconnected set of computers through which everyone could quickly access data and programs from any site. In spirit, the concept was very much like the Internet of today.

1961: Leonard Kleinrock publishes the first paper on packet switching theory.

1965: The first ever WAN:

in 1965 working with Thomas Merrill, Roberts connected the TX-2 computer in Mass. to the Q-32 in California with a low speed dial-up telephone line creating the first (however small) wide-area computer network ever built.

The conclusion from building this was that the circuit switched telephone system wasn’t up to the job, and Kleinrock’s argument for packet switching won the day from then on.

1966-7:: The plan for ARPANET is conceived and published.

1969: The first computers talk over the ARPANET. (And early hypertext – though not WWW)!:

Due to Kleinrock’s early development of packet switching theory and his focus on analysis, design and measurement, his Network Measurement Center at UCLA was selected to be the first node on the ARPANET. All this came together in September 1969 when BBN installed the first IMP at UCLA and the first host computer was connected. Doug Engelbart’s project on “Augmentation of Human Intellect” (which included NLS, an early hypertext system) at Stanford Research Institute (SRI) provided a second system) at Stanford Research Institute (SRI) provided a second node.

(IMP = Interface Message Processor, a packet switch). At the end of 1969 there were FOUR computers on the ARPANET.

1972: The first public demonstration of the ARPANET, and the introduction of email.

In October 1972 Kahn organized a large, very successful demonstration of the ARPANET at the International Computer Communication Conference (ICCC). This was the first public demonstration of this new network technology to the public. It was also in 1972 that the initial “hot” application, electronic mail, was introduced.

“email took off as the largest network application for over a decade”. The 1972 date means that I can say “when I was born, there was no such thing as email!” (Nor TCP, as we shall see next).

Also in 1972, Kahn introduces the idea of open-architecture networking allowing networks with different architectures to work together.

Kahn decided to develop a new version of the protocol which could meet the needs of an open-architecture network environment. This protocol would eventually be called the Transmission Control Protocol/Internet Protocol (TCP/IP). While NCP tended to act like a device driver, the new protocol would be more like a communications protocol.

There were four ground rules critical to Kahn’s thinking (and hence, these are the four ground rules that underpinned the development of TCP/IP):

  1. Each distinct network would have to stand on its own and no internal changes could be required to any such network to connect it to the Internet.
  2. Communications would be on a best effort basis. If a packet didn’t make it to the final destination, it would shortly be retransmitted from the source.
  3. Black boxes would be used to connect the networks; these would later be called gateways and routers.There would be no information retained by the gateways about the would be no information retained by the gateways about the individual flows of packets passing through them.
  4. There would be no global control at the operations level.

1973: Vint Cerf joins up with Kahn to spell out the details of what became TCP/IP, and Bob Metcalfe develops Ethernet technology at Xerox PARC.

The give and take was highly productive and the first written version of the resulting approach was distributed at a special meeting of the International Network Working Group (INWG) which had been set up at a conference at Sussex University in September 1973.

“The proliferation of LANs were not envisioned at the time, much less PCs and workstations…” aka, “I can’t see why the world should ever need more than 256 networks!”.

Thus a 32 bit IP address was used of which the first 8 bits signified the network and the remaining 24 bits designated the host on that network. This assumption, that 256 networks would be sufficient for the foreseeable future, was clearly in need of reconsideration when LANs began to appear in the late 1970s.

Work on packet based voice tranmission made it clear that some packet losses were better handled by the application than by the protocol…

This led to a reorganization of the original TCP into two protocols, the simple IP which provided only for addressing and forwarding of individual packets, and the separate TCP, which was concerned with service features such as flow control and recovery from lost packets.

UDP was added for those applications that did not want the full services of TCP.

1980’s: Network classes are introduced, together with DNS

In the beginning… “there were a fairly limited number of hosts, so it was feasible to maintain a single table of all the hosts and their associated names and addresses”.

The shift to having a large number of independently managed networks (e.g. LANs) meant that having a single table of hosts was no longer feasible, and the Domain Name System (DNS) was invented by Paul Mockapetris of USC/ISI.

This is also the period in which the single distributed routing algorithm implemented by all routers on the internet was replaced by a hierarchical model of routing with gateway protocols.

Alongside the story of the technology, this paper also shares some insights into what made it take off, and how the process of evolution itself has changed. Embedding in a popular operating system, adopting a faster paced open documentation format, and email were all key to the internet’s early success.

the incorporation of TCP/IP into the Unix BSD system releases proved to be a critical element in dispersion of the protocols to the research community. Much of the CS research community began to use Unix BSD for their day-to-day computing environment. Looking back, the strategy of incorporating Internet protocols into a supported operating system for the research community was one of the key elements in the successful widespread adoption of the Internet.

The normal cycle of academic publication was too slow, and in 1969 the RFC mechanism was born.

The effect of the RFCs was to create a positive feedback loop, with ideas or proposals presented in one RFC triggering another RFC with additional ideas, and so on. When some consensus (or at least a consistent set of ideas) had come together a specification document would be prepared. Such a specification would then be used as the base for implementations by the various research teams. … The RFCs are now viewed as the “documents of record” in the Internet engineering and standards community.

Before email, RFCs used to originate from single co-located groups of researchers.

After email came into use, the authorship pattern changed – RFCs were presented by joint authors with common view independent of their locations.

The paper concludes by commenting that the profileration of stakeholders – and with strong commercial interests – has changed the nature of evolving the internet.

The most pressing question for the future of the Internet is not how the technology will change, but how the process of change and evolution itself will be managed… If the Internet stumbles, it will not be because we lack for technology, vision, or motivation. It will be because we cannot set a direction and march collectively into the future.