Internet - History
In many ways the History of the Internet is linked to the development of the history of UNIX Operating System. Other significant factors that have influenced the development of the Internet include:
- The development of the concept of Packet Switching, and the Transaction Control Protocol / Internet Protocol (TCP/IP) standard for data packet transmission by Vint Cerf, Bob Kahn and Leonard Kleinrock
- The incorporation of TCP/IP in the UNIX (University of California at Berkley) operating system and later incorporations in operating systems by Microsoft, Apple, and others.
- The development of Routers and Switches by CISCO that enabled the development of packet switching networks. (A description of the current structure of the Internet is available.)
From a network standpoint, what we now call the Internet can be traced to a 1969 network set up by the U.S. Department of Defense called ARPAnet (Advanced Research Projects Agency Network). The agency was charged with creating a defense communication network that was robust enough to withstand a nuclear attack. Vinton Cerf (then at Stanford) and Robert Kahn (then at ARPA) created the concept of Packet Switching which was used as the foundation for ARPAnet. The network was used to connect various military and research facilities, and was also a research project in how to build a reliable intercontinental network. The network initially linked researchers with remote computer centers, allowing them to share resources such as hardware (disk space, computers) and software (databases, messages). The TCP/IP protocol was developed as a part of this project.
The TCP/IP protocols were introduced in 1974 during the development of the predecessor of the Internet, ARPANET (Advanced Research Projects Agency Network). The developers were Vint Cerf, Bob Kahn and Leonard Kleinrock (Cerf joined MCI in 1982). ARPANET was constructed so researchers could share information with university, military and defense contractors to study how communications could be maintained during disasters.
In 1980, the CSNET (Computer Science Network), a network linking computer science departments at a few universities, connected with DARPA (the Defense Advanced Research Projects Agency, ARPANET's successor.) BITNET joined the system in 1989.
The National Science Foundation Network (NSFNET), was established to connect the six supercomputer centers funded by NSF, and adopted TCP/IP as its protocol. By 1988, the network had 13 nodes using T-1 connections (leased lines with operating at 1.5 megabits.) In December 1992, the NSFNET backbone was converted to T-3 connections (45 MBps). Traffic on the backbone had grown from 195 million packets in 1988 to over 24 billion packets at the end of 1992.
UUCP (Unix to Unix system)
The UNIX operating system was originally developed by ATT's Bell Laboratories, in part, to facilitate the communication of different computers with different networking capabilities. The UUCP commands are a group of Unix utilities that are designed to facilitate file transfers from one Unix computer to another, connected over dial- up telephone links. A loose network of Unix users developed and became known as the UUCP network.
One of the common uses of the UUCP system is the distribution of information over USEnet (Users Network), a network of computers that run client software that allows the system to function as a distributed bulletin board system.
Other Networks in the Early 1980's
In the early 1980's, the original ARPAnet was physically split into two networks, a new ARPANET and an unclassified Military network called Milnet. Both networks used the same TCP/IP protocol for data communication and connections made between the two networks allowed intercommunication to continue. Access to the ARPAnet was restricted to military, defense contractors, and universities doing defense research.
Separately, the Computer Science Network (CSNET) connected university computing science departments, and BITNET began providing nationwide networking to the academic and research communities.
National Science Foundation Network (NSFNET)
In 1986 the National Science Foundation established the NSFNET, an network which linked researchers with five supercomputer centers. TCP/IP was chosen as the protocol for operating the network. As the NSFNET expanded connections to midlevel and statewide academic networks, it began to replace ARPA as the operator of the national backbone for computer to computer communication.
The ARPAnet was dismantled in March 1990. CSNET members began to connect to the NSFNET and CSNET ceased operation in 1991. In the mid 1980's, BITNET adopted the TCP/IP protocol and became interconnected with NSFNET.
By 1993, the NSFNET backbone contained 13 core nodal switching subsystems and 18 exterior nodal switching subsystems. These subsystems were partially funded by the National Science Foundation. Connected to these nodal switching subsystems were thousands of private and public computer networks connecting millions of computers around the world. It is this macro - networking that has become known as the INTERNET. While traffic on the NSFNET backbone was to be non-profit oriented, the spider-like web of the Internet allowed commercial organization to access the non NSFNET portions of the network.
By 1994, the National Science Foundation had announced that they would end their subsidy of the NSFNET, with private telephone companies (primarily MCI and ATT) taking on the responsibility of maintaining the Internet backbone on a for-profit basis. In an attempt to extend the frontiers of technology, the NSF is currently sponsoring a high speed research oriented network (vBNS).
A description of the current Internet Backbone is available.
Evolution of Internet Tools
In many ways, the development of Internet tools, especially Anonymous FTP, has lead to the explosive growth in the Internet. It is through these tools, typically client/server type application programs, that the Internet's chaos of information is attempted to be organized.
Using Unix UUCP commands, the Anonymous FTP (File Transfer Protocol) was developed in the late 1980's. Using the UNIX UCCP commands required a user to have an account on both the host computer and the remote computer. As a natural evolution, people began to establish special accounts for the purpose of allowing coworkers to download selected files without having an account on the remote computer. However, anonymous FTP still requires knowledge of the FTP command language to see what files are available, to change directories, or to upload or download files.
As a way to organize the chaos of information available on the Internet, in 1990 a group at the University of Minnesota developed the Gopher system, a client-server menu driven system to view and download files available for public access. The gopher system is, in part, a front end user interface that transparently uses the Anonymous FTP function to get files. With a simple menu selection interface, the user does not need to know FTP commands. The use of Gopher tools has been largely displaced by the use of the World Wide Web.
World Wide Web (WWW)
Developed in the early 1989 at CERN, Switzerland, the WWW can in many ways be thought of as a hypertext (or hypermedia) version of Gopher. The WWW is a client-server network consisting of three parts which extend beyond FTP and Gopher: Hypermedia Browser which displays hypertext files Standard Hypertext markup language called HTML (written in ASCII text file format) A loose convention for multimedia file types (image, sound, video)
The first browser was developed at CERN in Switzerland in 1989. The first graphical browser (MOSAIC) was developed at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana-Champaign and released in January 1993. Other popular browsers for PC/Windows include WinWeb and Netscape. Lynx is a popular text based browser developed at the University of Kansas.