ARPANET

ARPANET (Advanced Research Project Agency Network) was the original and first wide packet-switching network, originally created by a small team of research experts funded by DARPA in the United States Department of Defense.

Historical Background

The Creation of ARPA/DARPA

During the Cold War between the United States and Soviet Union, the United States government was primarily concerned with finding ways to protect its military communications system, and focused on finding ways to make its command and control network to able survive a nuclear attack from the Soviet Union.

In 1958, President Dwight Eisenhower instructed the creation of the Advance Research Project Agency (ARPA), which later became known as DARPA. after the Soviet Union launched Sputnik in 1957.

Paul Baran's Packet Switching: The Basis of ARPANET

The basis of the academic research for the ARPANET started with Paul Baran, a researcher from RAND, Inc. and one of the fathers of Internet. In 1962, Baran suggested to "design a more robust communications network using redundancy and digital technology." Although his idea was dismissed by many, Baran continued to work on developing his idea with colleagues at RAND. He envisioned a distributed communications wherein a network of unmanned nodes would serve as switches that would route information from one node to another until it reached its final destination. He later developed packet switching, a method of dividing information into "message blocks" before sending them out to a network. Each message block was be sent separately and then rejoined as a whole when reaching the final destination.

J.C.R. Licklider Leads IPTO

During the same year, DARPA commissioned Dr. J.C.R. Licklider from Bolt, Beranek and Newman to lead the Information Processing Techniques Office, which was mandated to further develop the Semi-Automatic Ground Environment (SAGE) program and build the first wide area computer network for the cross country radar defense system, interconnecting the three major defense sites of the United States, with the capability to survive a nuclear attack.

Licklider envisioned the project based on Baran's idea and method of packet switching. He also visualized a universal network that would allow people to communicate with each other using the computer. He referred to the first group of computer specialists working on the research project as the "Intergalactic Network." Licklider's interest in connecting the community through a computer network resulted in the creation of the ARPANET. He believed in the "promise offered by the computer as a communication medium between people, not as an arithmetic engine." In 1964, Licklider resigned from IPTO as Director and went to work for IBM.

Ivan Sutherland became IPTO Director

Licklider was succeeded by Ivan Sutherland, who developed the Sketchpad program which enabled computer displays to be saved and modified in memory. He also developed computer graphics. Inspired by his predecessors' vision of a universal network, in 1965, Sutherland awarded a contract Lawrence Roberts from MIT to develop the computer networking technology. Roberts worked with Thomas Marril and they were able to implement the first packet dial-up telephone connection exchange between a TX-2 computer at MIT and a Q-32 computer in California.

Robert Taylor Approval of ARPANET

In 1966, Robert Taylor became IPTO Director, succeeding Sutherland. He lobbied for additional funding to be able to carry out a research project to achieve a distributed communication network. A one million dollar funding was promised to him by DARPA then-Chief Charlie Hertzfeld, and Roberts was hired by IPTO as Chief Scientist. On June 21, 1968, Taylor approved the Resource Sharing Computer Network Report, a plan to create ARPANET, which was prepared by Roberts. ARPANET was officially developed on August 30, 1969. Lawrence Roberts became Director of IPTO the following month.

Development of ARPANET

Network Working Group

In 1968, computer experts from four research laboratories receiving research funding from IPTO were called together to identify and solve the technical problems associated with the development and completion of the ARPANET. Elmer Shapiro from the Stanford Research Institute (SRI) organized the first meeting, as instructed by ARPA, to discuss host-to-host problems. The meeting was attended by Steve Crocker, who represented UCLA, Steve Carr, from University of Utah, Jeff Rulifson from SRI, and Ron Stoughton from UCSB. The group decided to meet regularly, and became known as the Network Working Group. Crocker describe what transpired during the first meeting with the following statement:

"With no specific service definition in place for what the IMPs were providing to the hosts, there wasn't any clear idea of what work the hosts had to do. Only later did we articulate the notion of building a layered set of protocols with general transport services on the bottom and multiple application- specific protocols on the top. More precisely, we understood quite early that we wanted quite a bit of generality, but we didn't have a clear idea how to achieve it. We struggled between a grand design and getting something working quickly."

The NWG's initial advance protocol developments were DEL (Decode-Encode-Language) and NIL (Network Interchange Language), which were intended to give instruction on how to understand the messages that were received from the sender. The issue confronting the group was there was no official existing charter within ARPA or the universities thus, their their thing is broad and open. In 1969, Bolt, Beranek and Newman (BBN) submitted a detailed interface specification about the host and IMP which provide the NWG a basic starting point to develop the ARPANET, analyze its cost, performance and reliability.

NWG Started RFC

The Request for Comments (RFC) was started by the NWG when they realized that the discussions during their meetings needs to be recorded. Crocker organized the notes and wrote the discussions in their meetings with the label Request for Comments. According to Crocker, the NWG had a vision for inter computer communication but they struggled in creating a detailed protocol design. The RFC's served as a document to give status updates to the members of the NWG. It is open and provided an exchange of ideas and information between the computer scientist working on the ARPANET.

The ARPANET was born

The realization of the vision of Licklider for the ARPANET as a universal communication network became evident on September 1969 when NWG member Leonard Kleinrock, head of the Network Measurement Center (NMC) at UCLA and his team which include Vinton Cerf, Stephen Crocker, Bill Naylor, Jon Postel, and Mike Wingfield connected one of the center's SDS Sigma 7 computers to an Interface Message Processor (IMP). The team from UCLA were able to successfully exchange the message, "Do it to it, Truett" with BBN hardware designer Ben Barker. On that day, ARPANET/Internet was born.

The second node connected to the ARPANET was the NLS System (on-Line System) at the SRI which was developed by Douglas Engelbart. This was the first full ARPANET network connection using an SDS-940 computer with the Genie Operating System and a 50 kbps line from AT&T. However, the first test did not work properly and the system crashed. The second test worked fine according to Kleinrock.

The third connection added to the ARPANET was an IBM 360/75 computer using the OS/MVT operating system from the Culler-Fried Interactive Mathematics Centre at the University of California at Santa Barbara followed by the DED PDP-q0 computer using a Tenex Operatin System from University of Utah Graphix Department. The first four nodes connected to the ARPANET became operational.

The Network Control Program

Although ARPANET was already operational in 1969, Lawrence Roberts, IPTO's Senior Computer Scientist met with the NWG in UTAH and he emphasized that they need further achievement. He provided guidance to the group to develop a viable network protocol. In 1971, the group was able to create the Network Protocol Program (NCP), which became the standard networking program for the ARPANET. NCP's main function is to establish, break and switch connections, and control flow of communications between different host computer systems.There were already 15 sites connected to the NCP during the latter part of 1971. The NCP became the basis of Robert Kahn and Vinton Cerf in creating the TCP/IP of the current internet.

First 15 Sites Connected to ARPANET

The first 15 sites connected to NCP of ARPANET include:

1. BBN
2. Carnegie Mellon University
3. Case Western Reserve University
4. Harvard University
5. Lincoln Laboratories
6. Massachusetts Institute of Technology
7. NASA at AMES
8. RAND
9. Stanford Research Institute
10. Stanford University
11. System Development Corporation
12. UCLA
13. UCSB
14. University of Illinois at Urbana
15. University of UTAH

First International Connections to ARPANET

In 1973, the first two international sites connected to ARPANET were the the University College of London in England and the Royal Radar Establishment in Norway. During that year there already 37 connected located within the United States including a satellite link from California to Hawaii.

MILNET Splits from ARPANET

The Military Network (MILNET) was part of the ARPANET which serves as the backbone for the U.S. Department of Defense's unclassified e-mail and internet traffic with a total of 65 sites connected to the ARPANET. In 1983, MILNET decide to split from the ARPANET because of security reasons. There are only small remaining gateways connected to the ARPANET for e-mail exchange purposes only.

ARPANET Became Global

In 1985, connection to the ARPANET became global across the United States, Europe and Australia. There were already 2,000 hosts connected to TCP/IP which became the standard of inter-networking within the ARPANET. Jon Postel, who succeeded Steve Crocker as Chairman of the NWG assigned IP addresses to networks connected to the ARPANET.Jon Postel together with Paul Mockapetris and Craig Partridge from USC/ISI and BBN respectively develop the Domain Name System (DNS). By the end of 1989, connections to the internet reached around 160,000.

ARPANET Retires/ Internet Continues to Grow

In 1990, the ARPANET officially shut down. During that time there were already around 300,000 sites connected to the ARPANET. The connections were all moved to National Science Foundation Network (NSFNET) and took over the remaining responsibilities of the ARPANET research network. The internet increased rapidly during the 1990's and continuous to grow until today.