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Article 2: The ARPANet
by Das Behaelter
x Das Behaelter   - at 7:38 pm on Wednesday January 14ā 2004 x
x The precursor to the Internet, ARPANET was a large wide-area network created by the United States Defense Advanced Research Project Agency (ARPA). Established in 1969, ARPANET served as a testbed for new networking technologies, linking many universities x
x Das Behaelter The UseNet in 1986 World Wide - Conseptual design and BBN (not to be confused with BBS):

A company called Bolt Beranek and Newman, played a major role in the creation of the ARPANet. It was founded in 1948 as a consulting firm run by acousticians from MIT who consulted on the acoustics for building around the USA. In the Mid 1940ís Bolt was asked by the United Nations to design the acoustics for one of the UNís new buildings, realizing the work that was ahead of him, he asked Leo Beranek to join him. At the same time they hired another man, Robert Newman, to help with the work with the United Nations, together they formed BBN.
Historical Maps Of the ARPANet

The Early Years of the ARPANet:

On October 15 1957, USSR launched Sputnik One, and then Sputnik Two about a month later. The launch of Sputnik was the main cause for the US president Dwight Eisenhower to start new government agencies devoted to the development of new technologies. Never again did the Americans want to be behind in discovering the latest technologies. Two of the new government agency, founded as the result of the Eisenhower's decision, was the National Aeronautics and Space Administration (NASA) and the Advanced Research Project Agency (ARPA).

In 1958 ARPA opened it doors for the first time with Roy Johnson as the first director. By 1959, ARPA had a staff of seven with an annual budget of $150 million. ARPAís original budget was set at $2 billion per year but when NASA was created shortly after ARPA, the majority of the budget money was transferred over to NASA. In 1961 the first scientist, Jack P. Ruina became the third director of ARPA marking an important date the organizations history. Runia raised the annual budget from $150 to $250 million to develop projects such as ballistic missiles and nuclear testing.

By the Year 1961, The Air force was faced with major cut backs and found themselves stuck with a large Q-32 computer. Runia purchased the computer from the Air Force to start a new program on behavior science, funded by the Department Of Defense (DoD). Runia needed someone to run this new program at ARPA, and in the fall of 1962 he hired Joseph Carl Robnett Licklider, a psycho acoustician. Licklider accepted the position and became the first director of the Information Processing Techniques Office (IPTO).

Licklider was first interested in computers when he worked at MITís Lincoln Laboratories back in the early 1960ís. Licklider, using Lincoln Laboratoryís model TX-0 computer, became interested in the relationship between man and computers. In 1960 Licklider wrote a paper called "Man-Computer Symbiosis" where he wrote about the dissimilarities between computer and man and how each often benefit from each other. He gave an example of a fig tree and an insect Blastophaga grossorum. The insect pollinates the fig tree and the and the fig tree houses the insect, both could not live without each other and are completely dissimilar organisms. In the "Man-Computer Symbiosis" Licklider also explains the symbiosis of man and computer to come:

"In the anticipated symbiotic partnership, men will set the goals, formulate the hypotheses, determine the criteria, and perform the evaluation. Computing machines will do the routine work that must be done to prepare the way for insights and decisions in technical and scientific thinking" (Licklider, 1960).

Licklider was the first to believe that computers can be used for more that just large calculators but instead they could perform scientific thinking(Licklider p1).

In 1964 J.C.R Licklider left ARPA but not with out changing ARPAís main focus from war game scenarios to research into timesharing, computer graphics and computer languages.

In 1965 Ivan Sutherland, the second director of IPTO, hired Bob Taylor to work for IPTO. In 1966, only one year after being hired, Bob Taylor was promoted to director and became the third director of IPTO. One day Taylor was sitting in front of three computer terminals at ARPA and thought to himself: Ďwhy cant these computers be connected together, with one password and coded using one programming language instead of three different languages and passwords?í Taylor scratched his head for awhile and became the first person to have the idea of networking computers together. With solve the demand for large scale computers at each major university, and the problem of them not being able to communicate with each other, Taylor sat down with the director of ARPA, Charles Herzfeld, and requested funding for his new idea. Within twenty minutes of their meeting, Taylor received an increase of one million dollars in IPTO funding to commence the new project of connecting 4 university nodes right away, and up to a dozen in the future. Taylor knew that he needed someone fluent in telecommunications with past experiences working with computers to help him develop his idea. Taylor decided to call his friend Larry Roberts, who worked at Lincoln labs with computers like the TX-0 and TX-2, to help develop the standard interface between all the different computers.

Eventually Larry Roberts took over Bob Taylors job as director of IPTO during the creation of the first connections between the universities.

In early 1967 Bob Taylor called a meeting with employees of IPTO and ARPA at Ann Arbor Michigan to discuss the coming network projects. The meetings produced a lot of bickering over whether there should be one main host computer for the new network to process and transmit the data, or not. The problem they were facing was with a standard protocol for the computers to communicate to the host, every computer spoke a different languages and made the communication very dificult. On the way back to the airport after their meeting, Wes Clark came up with an idea for having small "hosts" at each computer in the network. Clark explained that with the smaller hosts, the network would consist of one language making it easier to control. The engineers decided that Frank Heart, who currently worked at BBN and who use to work as a computer systems engineer at MITís Lincoln Lab, would be the best suited to build the hosts computers.

By the end of 1967 Larry Roberts wrote his first proposal on the soon to be "ARPA net" using hosts, also know as Interface Message Processor (IMP), and Paul Barans and Donald Davies idea of packet switching. Roberts choose UCLA, Stanford Research Institute (SRI), University of Utah, and the University of California as the first institutes to receive the IMPís built by ARPA for the new ARPA.

In the early 1960ís, Paul Baren worked at RAND corporation trying to develop and find equipment that could withstand a nuclear attack. The equipment would eventually be used to send vital information from one area of the country to the other for the US government. He began researching how the human brain works when transmit information to the body via the neural net. If a cell is damaged in the brain, the message originally ment to be sent through the damaged cell, is re-routed around the damaged cell to the appropriate destination. Baran came up with the idea of dividing communication messages in parts, he called "blocks,", and then sending them individually across a medium to be reassembled at the destination. Katie Hafner and Matthew Lyon in "Where Wizards Stay Up Late" give another example of the block concept when they related the message transfer to freight movers. The authors describe how when a house is being moved from one end of the continent to the other it will usually be disassembled and then reassembled at the destination. This method of transporting a house is more efficient than transporting the house in one piece. The later method is still possible except not economically feasible.

The " blocks" as Baran called them, would contain important information embedded in them such as the blocks sender, receiver, and which order the blocks should be reassembled in. In 1965 Baran received the final approval from the Air Force to test out his theory of block switching. Before being able to finish his experiments, his work was thwarted by the The Defense Communication Agency who wished to control Baranís project, rendering Baran unable to finish his experiments and eventually abandoning the project.

Around the same time Paul Baran gave up on block switching, Donald Watts Davies, a Physicist from the British National Physical Laboratory, was developing a similar system of transporting information over a network. Unaware of Paul Baran work half way around the world, Davies came up with "Packet Switching" using similar principals as Barans Block Switching.

The ARPANet:

During the spring of 1969, BBN received their first Honeywell 516. The 516, or IMP #0 as it was soon to be called, was found to contain numerous problems with the hardware configurations overwhelming the "IMP Guys" with work. Shortly after IMP #0 arrived, Ben Baker and Severo Ornstein joined BBN and worked all summer fixing and correcting the bugs with the first IMP. When IMP #1 arrived two weeks before Labor Day, Baker and Ornstein expected the machine to have a few problems, lone and behold, when they turned the machine on, it didnít work. With very little time left, Baker was forced to fix IMP #1 at BBN. The IMP Guys were able to finished repairing the first IMP in time and shipped to UCLA on September 1st 1969.

At UCLA, the person responsible for receiving the IMP on September 1st was Len Kleinrock. Kleinrock Was faced with a problem of making their existing Sigma-7 computer work with the new IMP computer. Kleinrock had a number of students working for him that fall who attempted to make their Sigma-7 computer compatible with the IMP. The students, Steve Crocker, Vint Cerf and Jon Postel, developed their own Network Protocols that was used to make the Sigma-7 understand the IMPís language.

On October 1st, 1969, IMP #2 arrived at Stanford Research Institute on time and the first characters were transmitted over the new network from Stanford to UCLA. The first transmitted characters where "L, G and O." it was on this day that the Arpanet was born.

The Third IMP arrived at University of California on November 1st. Only a month later, the forth IMP was installed at University of Utah on December 1st 1969. While the third and forth IMP were being installed, Telnet was developed to allow users to log in to other computers connected in the network of IMPís (the new ARPANET). The network topology was set up in a configuration such that if data from a computer at UCLA was requested to go to Utah, it would need to pass through the IMP in Stanford. If for some reason the IMP in Stanford was down, the information would not be able to travel to Utah; this became a large cause of concern. The great minds of the ARPANET went back to the drawing board to try and develop a new system and method of connecting the computers together so that data could still be transmitted, even when a computer in the middle of the transmission path might be down.

By the summer of 1970, MIT, RAND, System Development Corp., and Harvard all received their own IMP while a second high speed(50 Kb/s) cross continent data line was added spanning from BBN in Massachusetts to RAND in Santa Monica, California. the second cross continent high speed lines leaving BBN. At that time, BBN, and in particular Alex McKenzie, was responsible for monitoring and controlling the cross continent data lines.

Original IMP's we very large and bulky due the design of the Honeywell 516's. BBN wanted to create a smaller IMP to replace to older ones and by the end of 1970, ARPA gave the OK to fund the project, using Honeywell 316's. One of the problems with an the old IMP was that it could only support a maximum of four terminals at a time while people were requesting multiple terminal connections. BBNdeveloped a new Terminal IMP called a TIP that could hold up to 63 connections at once, a significant improvement from the old IMP. The new TIP was delivered to BBN late in the summer of 1971 to be debugged before it was shipped out again.

FTP, TCP, and IP (TCP/IP):

Once the ARPANET was developed and in use, engineers and scientist noticed a lack of a standard means for transferring files over the new network. To solve this problem, a group of researchers got together for six months and came up with File Transfer Protocol (FTP), that specifies the format of the information traveling over the ARPANET. FTPís original release was finished in July 1972.

In October 1972, the ARPANET was demonstrated for the first time at the International Conference on Computer Communication in Washington. Before the conference, only a few in the computer community knew about the network. Larry Robert, the director of Information Processing Techniques Office (IPTO) at the time, asked Bob Kahn if he would be interested in organizing a demonstration of the ARPANET to the general public. Kahn, who was working at BBN, quickly recruited Al Vezza to aid him in the preparation for the conference. Hundreds of people attended the conference making it a complete success.

The Advanced Research Project Agency (ARPA) changed their name to the Defense Advanced Research Project Agency (DARPA) in 1972 in a decision to reflect more their focus on the defense aspect of research and development.

By 1973, other networks began to appear all over North America but none where able to connect with each other. In the spring of 1973, Vint Cerf and Bob Kahn pondered the possibility of connecting the ARPANET with the other newer networks. While at a conference, Cerf drew on a scrap piece of paper, how he envisioned the networks would be connected to each other. The two main types of networks in existence during 1973 were SATNET, a satellite network, and packet radio network. Cerf realized the need for a link or "gateway" to connect the individual networks together with a device so that each network would be fooled to believe it was connected to a network of the same type. That summer Cerf and Kahn worked out a proposal to the International Network Working Group on a "Protocol for Packet Network Inter-Communication". Their proposal described a new protocol that acted like an envelop carrying parts of a letter inside, where the broken up letters are called "datagrams.". The contents of the "letter" didn't mater to any network, only that the envelope reaches itís destination in one piece, and if it didnít, a new letter would be sent in its place. The new protocol, essential for networks to communicate with each other, was called the Transmission Control Protocol (TCP).

In 1977 Vint Cerf became the program manager for packet radio and SATNET research programs. In July, Cerf and Kahn demonstrated the ability of three independent networks communication with each other using TCP protocol by sending packets from San Francisco Bay to London then back to University of Southern California. The packet, in the end, traveled a total of 150,400 Km without loosing a single bit.

During a discussion between Cerf, Postel and Dany Cohen at ISI in 1978, they decided to split TCP into two separate protocols, TCP and Internet Protocol (IP). A good example of the responsibilities of TCP and IP can be found in the book "Where Wizards Stay Up Late". The book explains that TCP is responsible for breaking up the datagrams and messages and then reassembling them at the destination. IP is responsible for transmitting the individual datagrams over the network. To relate TCP/IP to the real world, TCP protocol would take a letter that you wrote on many pages and place it into multiple envelops (if the letter is really big). IP protocol then addresses the envelop and makes sure it arrived at its proper destination.

The famous @ symbol in every email address, was created in 1973 by Ray Tomlinson while working at BBN. Tomlinson was trying to figure out a way to send messages over the ARPANET using a standard messaging protocol. He developed the software called SNDMSG and the first email File Transfer Protocol called CPYNET which sent an electronic message over the ARPANET. While looking for a character to separate the username and computer name for SNDMSG, Tomlinson looked at his Model 33 Teletype and chose the @ symbol as the separator.

In 1977 BBN used the Transmission Control Protocol (TCP) for the first time on a UNIX system and demonstrated the full power of the TCP/IP protocols.

The Birth of the Internet:

By the late 1970ís and early 80, many new networks began to form. Some of the new networks were CSNET(Computer Science Research Network), BITnet (Because itís time network), SPAN (Space Physics Analysis Network), CDnet(Canadian Network) and one of the largest, the NSFnet or National Science Foundation Network. By the late 1970ís most people were using the new TCP/IP protocol but it wasnít until January 1st 1983, that the ARPANET finally switched over to using the new Protocol, this day became the official birth date of the Internet.

By 1989 the Internet was becoming more and more commercialized and less for itís original purpose, the research community. The newer and much faster NSFnet had far more computers than the ARPANET. Unable to keep up with new technologies and funding for the Arpanet, DARPA finally decided that it was time to pull the plug on the 22 year old network in 1989. The man who slowly disconnected the ARPANET computers and connected the terminals to the NSFnet back bone was Mark Pullen. No one really wanted to turn off ARPANET but it was bound to happen due to itís older and less efficient design.
Danny Cohen once said in a speech:

"In the beginning ARPA created the ARPANET.
And the ARPANET was without form and void.
And darkness was upon the deep.
And the spirit of ARPA moved upon the face of the network and ARPA said, ĎLet there be a protocol,í and there was a protocol. And ARPA saw that it was good.
And ARPA said, íLet there be more protocols,í and it was so. And ARPA saw that it was good.
And ARPA said, ĎLet there be more networks,í and it was so."

In the next article we will cover protocols... @:o)
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x Unread post xxUniversal Sea   - at 9:44 pm on Wednesday January 14ā 2004 x
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x Universal Sea Keep the articles coming, old chap. Good job.
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x x View the profile for Universal Sea x
x Unread post xDas Behaelter   - at 10:03 pm on Wednesday January 14ā 2004 x
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x Das Behaelter Thanks. @:o)
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x x View the profile for Das Behaelter x
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