Internet Chronology

This discussion reviews the chronology of events that has led to the Internet as it exists in the latter part of the 1990s. The discussion will be brief. For a more through discussion, see Douglas E. Comer Internetworking with TCP/IP: Volume I,Englewood Cliffs, NJ: Prentice-Hall, Inc., 1995.


Early Communication

From very early in the history of computers, people recognized the need to connect computers at a distance to one another. Early connections were point to point where one computer was connected directly to another by a telephone line and modem.

This arrangement began to change in the mid 1970s, spurred largely by the U.S. Military's need to connect a relatively large number of computers around the world for purposes of national defense. This need resulted in an initiative by the Advance Research Programs Agency ( ARPA), the chief research arm of the military, to develop networking technology that would allow multiple computers to be connected to a general network, and hence to one another, rather than through direct point-to-point connections.

One of the technologies that made this possible was the development of Local Area Networks (LANs), particularly Ethernet. Ethernet allowed multiple computers located within a few hundred yards of one another to be connected by a physical cable. Each such computer had its own unique address, and one computer could send a message to any other computer on the LAN by constructing a message that included that computer's address.

Chronology


Internetworking

By the latter part of the 1970s, networking had become a conglomeration of incompatible local and wide area networks. It became apparent to two visionary men at ARPA, Bob Kahn and Vinton Cerf, that some form of internetworking was needed in which networks with different architectures could be connected to form a single large virtual network. If this could be done, then any two computers located on any of the connected networks could communicate with one another. this vision led, first, to the concept of a general internetwork and, second, to the particular internetwork we call the Internet today.

The concept of an internet is illustrated in the figure below. It consists of a collection of independent networks that have been joined to form a single logical network. The point of contact between two networks is a special computer, called a router, that can recognize when a message is addressed to a computer on its local LAN and when it is addressed to a computer somewhere else. It directs the former to the appropriate computer and forwards the latter to another network to which it is connected that is closer to the intended destination.

Internetwork.
A collection of independent networks connected through routers.

The technical development that made internetworking, and hence the Internet, possible was the TCP/IP protocol, developed by Kahn and Cerf. TCP/IP is really two standards. The first, IP (Internet Protocol), allows any two computers to address messages to one another using a unique 32-bit address assigned to them. However, IP does not guarantee that the messages will be delivered or, if they are, that they will be delivered in their original order. Thus, a second protocol was needed, TCP (Transmission Control Protocol), that would address these needs. TCP is based on IP. Through an exchange of acknowledgments and other messages between computers, it enables packets of data to be sent and resent until all are received and the original sequence can be reconstructed by the receiving computer. Thus, TCP provides for a virtual "connection" similar to a telephone connection but without guarantees as to the time and latency that will be required for providing its services.

The political development that made the Internet possible was ARPA's adoption of TCP/IP as the standard for its ARPANET, insuring its wide-spread acceptance. This led to its later adoption as the basis for the Internet.

Chronology


The Origin and First Decade of the Internet

Today's Internet can trace its ancestry back to the early 1980s. It grew out of the original ARPANET that was set-up to support communication among military computers, defense department laboratories, and selected university departments. It was also marked by adoption of TCP/IP as its standard.

Shortly later, the National Science Foundation took the initiative to connect six supercomputer centers located around the country and the (approximately) 100 most important computer science, resulting in what came to be called NSFNET. Also connected were major industrial laboratories. It was not long, however, before other departments in academia recognized the usefulness of the Internet and began to have themselves connected.

Throughout the 1980s NSF remained a major promoter of the Internet, funding research and expanding the underlying infrastructure in several major overhauls. As a result, growth of the Internet remained exponential from 1983 until 1994, when it passed into private hands and comprehensive data were no longer collected.

Chronology


Recent Developments and the Future

During the mid-1990s, the Internet has continued to grow at an extremely fast rate, although accurate data are not available to document precisely what that growth has been. Perhaps the single most important development has been the emergence of the World Wide Web. Begun in late 1989 as an Internet application to allow nuclear and atomic scientists at several international sites to access technical documents, it has become by far the largest generator of traffic on the Internet. Part of its rapid expansion can be traced to the appearance in 1993 of the first graphical, point-and-click browser for the Web. As they say, after that, the rest is history.

As we look to the future, several developments are worth watching. One is the commercialization of the Net. Whereas for most of its lifetime, the Internet was supported by the U.S. Government, it has now been privatized and it seems obvious that much of its future growth will depend on support from commercial interests based on its capacity to generate profits.

Another trend to monitor is the increasingly comprehensive nature of the Internet and the WWW as a computer and communications infrastructure. It may come to pass that virtually all computing will take place within that context. Certainly Java is a development that could play an important part in this transition.

A third trend to watch is whether or not the Internet can adapt its basic architecture to meet the computing requirements of real-time applications, such as voice and video. If it does, then it could eventually encompass other existing networks, such as the telephone system and cable video.