Category: Timeline Stories

The most popular network protocol in the world, the TCP/IP protocol suite, was designed in the first half of the 1970s by two DARPA scientists—Vint Cerf and Bob Kahn, persons most often called the fathers of the Internet.

Vinton Gray “Vint” Cerf (born 23 June 1943 in New Haven, Connecticut) obtained his B.S. in Math and Computer Science at Stanford University in 1965 and went to IBM, where he worked for some two years as a systems engineer, supporting QUIKTRAN—a system to make time-shared computing more economical and widely available for scientists, engineers, and businessmen.

In 1967 he left IBM to attend graduate school at the University of California, Los Angeles (UCLA), where he earned his master’s (in 1970) and Ph.D. degree (1972) in Computer Science. During his graduate student years, he studied under Professor Gerald Estrin, and worked in Leonard Kleinrock‘s data packet networking group that connected the first two nodes of the ARPANET, the predecessor to the Internet. He worked as a Principal Programmer, participating in a number of projects, including the ARPANet Network Measurement Center, a video graphics project including a computer-controlled 16 mm camera, development of ARPANet host protocol specifications.

While at UCLA, he also met Bob Kahn, who was working on the ARPANet hardware architecture in BBN (Bolt Beranek and Newman).

Robert Elliot Kahn (born 23 December 1938) received a B.E.E. degree from the City College of New York in 1960, and M.A. and a Ph.D. degree from Princeton University in 1962 and 1964 respectively.

After graduation, he received a position on the Technical Staff at Bell Labs and then became an Assistant Professor of Electrical Engineering at MIT. He took a leave of absence from MIT to join Bolt Beranek and Newman, where he was responsible for the system design of the Arpanet, the first packet-switched network, and was involved in the building of the Interface Message Processor.

In 1972, Kahn was hired by Larry Roberts at the IPTO to work on networking technologies, and in October he gave a demonstration of an ARPANet network connecting 40 different computers at the International Computer Communication Conference, making the network widely known for the first time to people from around the world and communication engineers realizing that packet switching was a real technology.

At the IPTO, Kahn worked on an existing project to establish a satellite packet network and initiated a project to establish a ground-based radio packet network. These experiences convinced him of the need for the development of an open-architecture network model, where any network could communicate with any other independent of individual hardware and software configuration. Kahn, therefore, set four goals for the design of what would become the Transmission Control Protocol (TCP):
• Network connectivity. Any network could connect to another network through a gateway.
• Distribution. There would be no central network administration or control.
• Error recovery. Lost packets would be retransmitted.
• Black box design. No internal changes would have to be made to a network to connect it to other networks.

In the spring of 1973, Vinton Cerf joined Kahn on the project. They started by conducting research on reliable data communications across packet radio networks, factored in lessons learned from the Networking Control Protocol, and then created the next-generation Transmission Control Protocol (TCP), the standard protocol used on the Internet today.

In the early versions of this technology, there was only one core protocol, which was named TCP. And in fact, these letters didn’t even stand for what they do today Transmission Control Protocol, but they were for the Transmission Control Program. The first version of this predecessor of modern TCP was written in 1973, then revised and formally documented in RFC 675, Specification of Internet Transmission Control Program from December 1974.

What is the current status of the Internet Protocol Suite (commonly known as TCP/IP)?

It is the set of communications protocols used for the Internet and other similar networks. It is named after two of the most important protocols in it: the Transmission Control Protocol (TCP) and the Internet Protocol (IP), which were the first two networking protocols defined in this standard. Today’s IP networking represents a synthesis of several developments that began to evolve in the 1960s and 1970s, namely the Internet and LANs (Local Area Networks), which emerged in the mid- to late-1980s, together with the advent of the World Wide Web in the early 1990s.

The design of the network included the recognition that it should provide only the functions of efficiently transmitting and routing traffic between end nodes and that all other intelligence should be located at the edge of the network, in the end nodes. Using a simple design, it became possible to connect almost any network to the ARPANET, irrespective of their local characteristics. One popular saying has it that TCP/IP, the eventual product of Cerf and Kahn’s work, will run over two tin cans and a string.

A computer or device called a router (a name changed from a gateway to avoid confusion with other types of gateways) is provided with an interface to each network, and forwards packets back and forth between them. Requirements for routers are defined in RFC 1812.

DARPA then contracted with BBN Technologies, Stanford University, and the University College London to develop operational versions of the protocol on different hardware platforms. Four versions were developed: TCP v1, TCP v2, a split into TCP v3 and IP v3 in the spring of 1978, and then stability with TCP/IP v4—the standard protocol still in use on the Internet today.

In 1975, a two-network TCP/IP communications test was performed between Stanford and University College London (UCL). In November 1977, a three-network TCP/IP test was conducted between sites in the US, UK, and Norway. Several other TCP/IP prototypes were developed at multiple research centers between 1978 and 1983. The migration of the ARPANET to TCP/IP was officially completed on 1 January 1983, when the new protocols were permanently activated.

In March 1982, the US Department of Defense declared TCP/IP as the standard for all military computer networking. In 1985, the Internet Architecture Board held a three-day workshop on TCP/IP for the computer industry, attended by 250 vendor representatives, promoting the protocol and leading to its increasing commercial use.

The Internet Protocol Suite, like many protocol suites, may be viewed as a set of layers. Each layer solves a set of problems involving the transmission of data and provides a well-defined service to the upper layer protocols based on using services from some lower layers. Upper layers are logically closer to the user and deal with more abstract data, relying on lower-layer protocols to translate data into forms that can eventually be physically transmitted.

The TCP/IP model consists of four layers, as it is described in RFC 1122. From lowest to highest, these are—the Link Layer, the Internet Layer, the Transport Layer, and the Application Layer. It should be noted that this model was not intended to be a rigid reference model into which new protocols have to fit in order to be accepted as a standard.

Almost all operating systems in use today, including all consumer-targeted systems, include a TCP/IP implementation.

The most important feature of a computer virus is its ability to self-replicate (in a sense every self-replicating program can be called a virus). The idea of self-replicating programs can be traced back as early as 1949 when the mathematician John von Neumann envisioned specialized computers or self-replicating automata, that could build copies of themselves and pass on their programming to their progeny.

If a computer virus has the ability to self-replicate over a computer network, e.g. Internet, it is called a worm. It is not known who created the first self-replicating program in the world, but it is clear that the first worm in the world (so-called the Creeper worm) was created by the BBN engineer Robert (Bob) H. Thomas probably in 1971.

The company BBN Technologies (originally Bolt, Beranek and Newman) was a high-technology company, based in Cambridge, Massachusetts, which played an extremely important role in the development of packet switching networks (including the ARPANET and the Internet).

A number of well-known computer luminaries have worked at BBN, including Robert Kahn, Joseph Licklider, Marvin Minsky, Ray Tomlinson, John McCarthy, etc. Between them was the researcher Robert H. (Bob) Thomas, working in a small group of programmers who were developing a time-sharing system called TENEX, that ran on Digital PDP-10 (see the lower image).

Let’s clarify, the Creeper wasn’t a real virus, not only because the notion of computer virus didn’t exist in the 1970s, but also because it was actually an experimental self-replicating program, not destined to damage, but to demonstrate a mobile application.

Creeper was written in PDP-10 assembly, ran on the old Tenex operating system (Tenex is the OS that saw the first email programs, SNDMSG and READMAIL, in addition to the use of the “@” symbol on email addresses), and used the ARPANET (predecessor of the current Internet) to infect DEC PDP-10 computers running the TENEX. Creeper caused infected systems to display the message “I’M THE CREEPER : CATCH ME IF YOU CAN.

The Creeper would start to print a file, but then stop, find another Tenex system, open a connection, pick itself up and transfer to the other machine (along with its external state, files, etc.), and then start running on the new machine, displaying the message. The program rarely if ever actually replicated itself, rather it jumped from one system to another, attempting to remove itself from previous systems as it propagated forward, thus Creeper didn’t install multiple instances of itself on several targets, actually, it just moseyed around a network (the techniques developed in Creeper were later used in the McROSS (Multi-computer Route Oriented Simulation System), an air traffic simulator, to allow parts of the simulation to move across the network).

It is uncertain how much damage (if any) the Creeper actually caused. Most sources say the worm was little more than an annoyance. Some sources claim that Creeper replicated so many times, that it crowded out other programs, but the extent of the damage is unspecified. Anyway, it immediately revealed the key problem with such worm programs: the problem with controlling the worm.

The Creeper program led to further work, including a version by a colleague of Thomas—Ray Tomlinson, that not only moved through the net but also replicated itself at times. To complement this enhanced Creeper, in 1972 the Reaper program was created, which moved through the net, replicating itself, and tried to find copies of Creeper and log them out. Thus, if Creeper was the first virus, then Reaper was the first anti-virus software.

Note from the author (Georgi Dalakov):
After the composition of this article in February 2010, I referred to Mr. Ray Tomlinson, the creator of Reaper, with an appeal for comment. He was so kind to provide me with one, as follows:
Your description agrees with my recollection, though I think it was somewhat later than 1970 and I don’t recall some of the details you give, such as printing a file as evidence of its presence on a particular machine (though it must have done something to indicate its progress). I do recall making the modifications you indicate and thinking of it as the escalation of an arms race.
There was a server (or daemon or background process) (RSEXEC, I think it was called) running on the individual machines that supported this activity. That is, the creeper application was not exploiting a deficiency of the operating system. The research effort was intended to develop mechanisms for bringing applications to other machines with intention of moving the application to the most efficient computer for its task. For example, it might be preferable to move the application to the machine having the data (as opposed to bringing the data to the applications). Another use would be to bring the application to a machine that might have spare cycles because it is located in a different timezone where local users are not yet awake. The CREEPER application was a demonstration of such a mobile application.

At the beginning of the 1970s came a time, which was dreamed of by the pioneers like Herbert Wells in his World Brain and Paul Outlet in his Universal Network for Information and Documentation. Time to establish something like a giant world library, which contains all human knowledge and is easily accessible all over the world. If we have the storage (computers), and we have the communication media (Internet), how can we start with this giant task? The easiest way is to collect in one place all books, published by human beings.

And who was the first?

Michael Stern Hart (born on 8 March 1947, in Tacoma, Washington, died on 6 September 2011, Urbana, Illinois) is the founder of the first project for a digital library—Project Gutenberg, which makes electronic books freely available via the Internet.

Studying at the University of Illinois (USA), in July 1971, Hart managed to get access to a Xerox Sigma V mainframe computer in the university’s Materials Research Lab. (Hart’s brother’s best friend was the mainframe operator, so he helped). This particular computer was one of the 15 nodes on the computer network that would become the Internet. Although the focus of computer use there tended to be data processing, Hart was aware that it was connected to a network and chose also to use his computer time for information distribution. He received an account with a virtually unlimited amount of computer time (not bad to have a friend computer operator 🙂 its value at that time has since been variously estimated at $100,000 or $100,000,000. Hart has said he wanted to give back this gift by doing something that could be considered to be of great value. His initial goal was to make the 10000 most consulted books available to the public at little or no charge and to do so by the end of the 20th century.

Hart related that after his account was created on 4 July 1971, he had been trying to think of what to do with it and had seized upon a copy of the United States Declaration of Independence, which he had been given at a grocery store on his way home from watching fireworks that evening. He typed the text into a teletype machine but was unable to transmit it via e-mail. Thus, to avoid crashing the system, it had to be downloaded individually.
This was the beginning of Project Gutenberg.
The mission statements for the project, formulated later, were:
• Encourage the Creation and Distribution of eBooks
• Help Break Down the Bars of Ignorance and Illiteracy
• Give As Many eBooks to As Many People As Possible

Most of the early postings were typed in personally by Hart, as was the case with Declaration. He began posting text copies of such classics as the Bible, and the works of Homer, Shakespeare, and Mark Twain. As of 1987, he had typed in a total of 313 books in this fashion. Then, through being involved in the University of Illinois PC User Group and with assistance from Mark Zinzow, a programmer at the school, Hart was able to recruit volunteers and set up an infrastructure of mirror sites and mailing lists for the project. With this, the project was able to grow much more rapidly.

Today Project Gutenberg is available at www.gutenberg.org. Its e-texts are produced (usually scanned) by Project’s many volunteers. The collection includes public domain works and copyrighted works included with express permission. As of December 2009, Project Gutenberg claimed over 30000 (most of the books are in the English language, but there are also books in French, German, Finnish, Dutch, Chinese, Portuguese, etc.) items in its collection, primarily works of literature from the Western cultural tradition. In addition to literature such as novels, poetry, short stories, and drama, Project Gutenberg also has cookbooks, reference works, and issues of periodicals. The Project Gutenberg collection also has a few non-text items such as audio files and music notation files. It is affiliated with many projects of independent organizations that share the same ideals, and have been given permission to use the Project Gutenberg trademark. As of 2022, Project Gutenberg is a library of over 60000 free eBooks.

Raymond (Ray) Samuel Tomlinson (born 1941 in Amsterdam, New York, died in Lincoln, Massachusetts, on 5 March 2016) is a graduate of Rensselaer Polytechnic Institute (the oldest technological university in the USA) and a long-time employee of the company Bolt, Beranek, and Newman, which had won the contract to create ARPANET, the predecessor of the Internet.

Tomlinson started his work on the ARPANET, developing the Network Control Protocol (NCP), the predecessor of TCP/IP, for a time-sharing system called TENEX, as well as network programs, such as an experimental file transfer program (called CPYNET).

During the summer and autumn of 1971, he was making improvements to the local inter-user mail program (called SNDMSG). Single-computer electronic mail had existed since at least the early 1960s and SNDMSG was an example of that. SNDMSG allowed a user to compose, address, and send a message to other users’ mailboxes on the same computer. Tomlinson hit on the idea to merge an intra-machine message program with another program developed for transferring files among the remote ARPANET computers.

There were other people, who developed similar programs. Richard W. Watson, for example, thought of a way to deliver messages and files to numeric printers at remote sites. He filed his “Mail Box Protocol” as a draft standard under RFC 196 in July 1971, but the protocol was never implemented.

In contrast, SNDMSG sent messages to named individuals (computer users), but only working on the same computer. Tomlinson decided to improve it, in order to send messages to users at remote computers also.

Tomlinson examined the mailbox as a file with a particular name. The users could write more data onto the end of the mailbox, but they couldn’t read or overwrite what was already there. The idea of Tomlinson was to use CPYNET to append material to a mailbox file just as readily as SNDMSG could. SNDMSG could easily incorporate the code from CPYNET and direct messages through a network connection to remote mailboxes in addition to appending messages to local mailbox files.

The missing piece was that the experimental CPYNET protocol had no provision for appending to a file. It could just send and receive files. Tomlinson had to make a minor addition to the protocol and incorporate the CPYNET code into SNDMSG.

Next problem was to provide a way to distinguish local mail from network mail. Tomlinson chose to append an at sign (@) and the hostname to the user’s (login) name. He chooses namely the at sign because the purpose of this sign (in English) was to indicate a unit price (for example, 10 items @ $1.95, i.e. 10 items with a price of $1.95). Besides that, at signs didn’t appear in names so there would be no ambiguity about where the separation between the login name and host name occurred. The at sign also had no significance in any editors, that ran on TENEX. Thus he used the at sign to indicate that the user was “at” some other host rather than being local.

The first message using the new command was sent at the end of 1971 and was sent between two machines, that were literally side by side (see the nearby photo) and ran the TENEX time-sharing monitor. The only physical connection they had was through the ARPANET. In the foreground of the photo is the computer BBN-TENEXA (BBNA). In the background is the computer BBN-TENEXB (BBNB) from which the first email was sent. On the left, foreground, is the Teletype KSR-33 terminal, on which the first email was printed. Immediately behind and largely obscured is another KSR-33 terminal, on which the first email was typed. BBNA was a Digital Equipment Corporation KA10 (PDP-10) computer with 64K (36-bit) words of (real magnetic) core memory. BBNB was a smaller machine with only 48K words.

Tomlinson sent a number of test messages to himself from one machine to the other. When the inventor was satisfied that the program seemed to work, he sent a message to the rest of the group, explaining how to send messages over the network. Thus the first use of network email announced its own existence.

The next release of TENEX went out in early 1972 and included the version of SNDMSG with network mail capabilities. The CPYNET protocol was soon replaced with a real file transfer protocol having specific mail handling features. Later, a number of more general mail protocols were developed also.

In 1996, for the first time in the USA, more electronic mail was being sent than postal mail. In 2003, for the first time spam accounts for over one-half of all e-mails sent. In 2010, the number of emails sent reached 107 trillion (sadly, 89.1% percent of emails were spam). In 2012 total number of email accounts was 3.3 billion, the number increased to 4 billion as of 2020, and 4.3 billion email users are expected at the end of 2022.

In 1971 Murray Turoff (born in San Francisco, on 13 February 1936), a B.A. in Mathematics and Physics from the University of California at Berkeley and a Ph.D. in Physics from Brandeis University, while working in the U.S. Office of Emergency Preparedness (a federally coordinated system that augments the Nation’s medical response capability), designed the Emergency Management Information Systems And Reference Index (EMISARI), which appears to be the first multi-machine chat system.

The original purpose of the system was to help exchange information on opinion surveys between networking experts and academics in geographically distributed locations, which could help the government respond to emergencies. This system and others Turoff designed (RIMS, IRIS, PREMIS) were used for a decade and a half by the U. S. Government for crisis management monitoring of most economic disruptions (e.g., coal strikes, transportation strikes) and commodity shortages (e.g., oil, gas, fertilizer). That system also provided the first example of instant messaging in an operational environment.

In 1971, EMISARI was put to one of its first practical uses to coordinate policy information for U.S. President Nixon’s wage and price control program to fight high inflation. Users of EMISARI logged in to the system through teletypewriter terminals linked to a central computer, using long-distance phone lines.

The EMISARI chat functionality was called the Party Line, and was originally developed to replace telephone conferences which might have 30 or so participants, but where no one could effectively respond and take part in a meaningful discussion. Party Line had a range of useful features familiar to users of modern chat systems, such as the ability to list the current participants, and the invocation of an alert when someone joined or left the group.

EMISARI was written under EXEC VIII on a UNIVAC computer which had newly developed multiprocessing capabilities, making possible the new, interactive functionality that Turoff designed. As with current online chat rooms, the system showed a list of participants and gave alerts when someone joined or left the chat. As many as 300 experts were set up to coordinate how the country would respond. EMISARI continued to be used by the US Government for the management of emergency situations until 1986.

EMISARI had more features than many conferencing systems developed thirty years later, including real-time voting, data collection assignment and reporting, and discussion threads for individual database elements.

The idea of markup languages was apparently first publicly presented by the engineer William W. Tunnicliffe (1922-1996) from Washington, D.C. In September of 1967, during a meeting at the Canadian Government Printing Office, Tunnicliffe gave a presentation on the separation of the information content of documents from their format. In the 1970s, Tunnicliffe led the development of a standard called GenCode for the publishing industry and later was the first chair of the International Organization for Standardization. At almost the same time, the book designer Stanley Rice published vague speculation along similar lines in the late 1960s. Rice, as an editor at a Major Publishing House, was writing about “Standardized Editorial Structures”. This was the beginning of a movement to separate the formatting of a document from its content.

In 1969 Charles F. Goldfarb, a graduate of Harvard Law School and Columbia College, hit upon the basic idea of markup languages while working on a primitive document management system intended for law firms, and at the end of the same 1969, leading a small team at IBM, developed the first markup language, called Generalized Markup Language, or GML. Later on, however, Goldfarb explains that he actually coined the term GML to be an anagram for the three researchers, Charles Goldfarb, Ed Mosher, and Ray Lorie, who worked also on the project. Goldfarb was also the man, who coined the term “markup language.”

Goldfarb felt that GML should both describe the structure of the document and be structured in a way, such that it could be both human-readable and machine-readable. At the beginning of the 1970s, he continued his work at IBM as GML began to grow in popularity. Several years later, in 1974, and with the influence of hundreds of people, the next version of the language, called  Standard Generalized Markup Language (SGML) was born. SGML added additional concepts that were not part of the GML project such as link processing, concurrent document types, and most importantly the concept of a validating parser (called ARCSGML), that could read and check the accuracy of the Markup code.

As Markup languages go, SGML was powerful, flexible, and complex, and was used extensively in the document processing of the huge IBM documentation. It’s widely known that when at the end of the 1980s Tim Berners-Lee and Robert Caillau created HTML, and they based their hypertext publishing language namely on SGML. HTML as a subset of SGML is on the other hand easy to learn, but not nearly as powerful. Their system used a NeXT computer and incorporated the concept of hyperlinks. Tim realized the need for a Markup language that was easy to use and implement into their system. In 1991 the Web debuted on the Internet and it was the simplicity of HTML that made the Web grow at a feverish pace.

As remembered later Goldfarb in an interview:
We were trying to do an automated law-office application. I had been a lawyer (in fact, I still am). Lawyers must do research on existing case law, decisions of court, and so on, to find out which ones are applicable to a given situation, find out what the previous legal rulings have been, and then merge that with text that the lawyer has written himself. Eventually, if it’s, say, a brief for the court, he must then compose it and print it. At the time, which was 1969 or 1970, there weren’t any systems available that did these three things. So in order to get the systems to share the data we had to come up with a way to represent it that was independent of any of those applications.
It was a very small research project. There was initially myself and another researcher, Ed Mosher, working on it full time. Then, we had part-time consulting from a very brilliant fellow named Ray Lorie who is also one of the pioneers of relational databases. Ray had the most brilliant insight into the whole thing, which is that all the elements that are tagged the same way should be processed the same way. Our manager, Andy Symonds, contributed technically as well…

In 1975, Goldfarb moved from Cambridge, Massachusetts to Silicon Valley and became a product planner at the IBM Almaden Research Center. There, he convinced IBM’s executives to deploy GML commercially in 1978 as part of IBM’s Document Composition Facility product. Development informally began that year on what ultimately became the SGML standard, and Goldfarb eventually became chair of the SGML committee. SGML was standardized and released by ISO in 1986.

Larry Roberts (1937-2018) is sometimes called the “father of the ARPANET.” He earned this nickname by directing the team of engineers that created the ARPANET. Roberts was also the principal architect of the ARPANET.

Lawrence (Larry) Gilman Roberts was born on 21 December 1937 in Westport, Connecticut, as the son of Elliott and Elizabeth Roberts, who both had earned their doctorates in chemistry. During his youth, he built a Tesla coil, assembled a television, and designed a telephone network built from transistors for his parent’s Girl Scout camp.

Roberts attended the Massachusetts Institute of Technology (MIT), where he received his bachelor’s degree (1959), master’s degree (1960), and Ph.D. (1963), all in electrical engineering.

After receiving his Ph.D. in 1963, Roberts continued to work at the MIT Lincoln Laboratory, mainly in the field of computer graphics (see the lower image). Having read the seminal 1961 paper “Intergalactic Computer Network” of Licklider, Roberts started to work also in the field of computer-to-computer networks, that could communicate via data packets.

In 1966, Robert Taylor assumed the directorship of ARPA’s Information Processing Techniques Office (IPTO), Licklider’s old post. He noticed that IPTO research contractors were constantly requesting more computing resources. Most of them wanted their own computers—an expensive luxury. Taylor also noticed that there was a lot of duplication of research. This waste of resources also costs money. Building on the theoretical legacy of Licklider, Taylor decided that ARPA should link the existing computers at ARPA-funded research institutions together. This would allow everybody on the network to share computing resources and results.

With the go-ahead to build a network, Taylor began looking for someone to manage the project. His first choice was namely the young Larry Roberts. Roberts was a shy man who was well-respected in his field. He was known for his good management skills and dedication to his work.

Roberts also had experience with network computing (which was a rare commodity in those days). In 1965, a psychologist named Tom Marill, who had studied under Licklider and been influenced by his interest in computers, approached ARPA and proposed a project to conduct an experiment linking Lincoln Lab’s TX-2 computer to the SDC Q-32 computer in Santa Monica. ARPA officials thought it was a good idea, but suggested that Marill carry out his experiment under the sponsorship of the Lincoln Lab, which he did. Officials at the Lincoln Lab put Roberts in charge of the project. The experiment although much smaller in scope than the ARPANET would be was a success. Response times were slow and connection reliability was often poor, but Marill’s project provided a solid first step. In 1966 Roberts and Marill publish a paper about their earlier success at connecting over dial-up.

In 1966, Taylor managed to persuade Roberts to accept the position of manager and principal architect of the ARPANET, the precursor to the Internet. Roberts designed and managed the building of the ARPANET over the next 6 years. In 1967, he attended a meeting for ARPA’s Principal Investigators or PIs (scientists heading ARPA-funded research projects). The main topic was the new networking project. Roberts laid out his plans. He wanted to connect all ARPA-sponsored computers directly over dial-up telephone lines. Networking functions would be handled by “host” computers at each site. This idea was not well-received. Researchers did not want to relinquish valuable computing resources to administer this new network and did not see how they would benefit from sharing resources with other researchers.

In 1989, Roberts recalled: “Although they knew in the back of their mind that it was a good idea and were supportive on a philosophical front, from a practical point of view, they—Minsky and McCarthy [two prominent computer scientists], and everybody with their own machine-wanted [to continue having] their own machine. It was only a couple of years after they had gotten on [the ARPANET] that they started raving about how they could now share research, and jointly publish papers, and do other things that they could never do before.”

Many also foresaw problems trying to facilitate communication between machines with many different incompatible operating systems and languages. All in all the reception to Roberts’ plans was a cold one.

Toward the end of the meeting, a man named Wesley Clark (the creator of the LINC computer) handed Roberts a note that read: You’ve got the network inside out. After the meeting, Roberts talked with Clark, who suggested that Roberts employ small computers at each site to handle networking functions and leave the host computers alone. All of the small computers could speak the same language which would facilitate communication between them. Each host computer would only have to adapt its language once in communicating with its small computer counterpart. Each host computer would be connected to the network via its small computer which would act as a sort of gateway. The small computers could also remain under more direct ARPA control than the large host computers.

Roberts adopted Clark’s idea. He called the small computers Interface Message Processors (IMPs). Roberts decided that the network should start out with four sites: UCLA, the Stanford Research Institute (SRI), the University of Utah, and UC Santa Barbara. This would be the core and the network could grow from there. (SRI had been chosen as one of the first sites partly because Doug Engelbart was there.) By the middle of 1968, Roberts sent out a request for bids to build the IMPs to 140 companies. In late December, the bidding was over. The best offer came from Bolt, Beranek and Newman (BBN), where used to work Licklider.

Packet switching proved very controversial to communications people. The conventional opinion then held that packet switching could never work. Many of the University’s computer research centers also felt the network would steal their computer power. However, Roberts’ team, in conjunction with contractor BBN, which assembled and installed the hardware, proved them both wrong and the network worked with much higher efficiency and utility than either group imagined.

In August 1969, BBN delivered the first IMP to UCLA. A month later, the second was delivered to SRI. The two were connected and the ARPANET was born. By 1973, 23 computers were connected worldwide. At that point, Roberts turned the development over to Bob Kahn and Vint Cerf and left ARPA to form the first commercial packet network.

After ARPA, Dr. Roberts founded the world’s first packet data communications carrier, Telenet – the company that developed and drove the adoption of the popular X.25 data protocol. Roberts was CEO from 1973 to 1980. Telenet was sold to GTE in 1979 and subsequently became the data division of Sprint. From 1983 to 1993, Roberts was Chairman and CEO of NetExpress, an electronics company specializing in packetized fax and ATM equipment. Roberts was president of ATM Systems from 1993 to 1998.

Larry Roberts died at his California home from a heart attack on 26 December 2018.

Joseph Carl Robnett Licklider (1915-1990), called also J.C.R. or “Lick”, was an American scientist, an imaginative experimenter, and a theoretician, who left major marks not only in computer science but also in psychoacoustic.

In the 1950s, working as an associate professor at MIT (Massachusetts Institute of Technology) and director of the Acoustics Laboratory, Lick got caught up in Project SAGE. It was a crash program to create a computer-based air-defense system against Soviet long-range bombers. The computer in SAGE was Whirlwind (see the lower photo), which had been under development at MIT since 1944 and recently had been completed under the direction of Jay Forrester. Other early computers, such as ENIAC, had started out as giant calculators, with an operating style to match: You entered the numbers and eventually got back a printout with the answer. This came to be known as batch-processing. Whirlwind, by contrast, had started out as a flight simulator and had evolved into the world’s first real-time computer: It would try to respond instantly to whatever the user did at the console. The challenge was to prove that a computer could take the data coming in from a new generation of air-defense radars and display the results rapidly in a meaningful form.

Lick headed SAGE’s human-factors team, and he saw the project as an example of how machines and humans could work in partnership. Without computers, humans couldn’t begin to integrate all that radar information. Without humans, computers couldn’t recognize the significance of that information or make decisions.

Developing in the 1950s his theories of perception Lick used analog equipment for generating stimuli, collecting responses, analyzing them, and so on. He found out, however, that analog computers were not flexible enough to help him in his theory-building effort. This disappointment with analog computers marks the beginning of his love affair with digital computers as modeling tools.

In 1957 Lick left MIT for the small consulting firm Bolt Beranek and Newman (BBN), as vice president and director of research of the departments of psychoacoustics, engineering psychology, and information systems. His train of thought went into strange new paths. That spring and summer, he kept track of what he actually did during the day, analyzing later the data with shocking results. “About 85 percent of my ‘thinking’ time was spent getting into a position to think, to make a decision, to learn something I needed to know,” he later wrote. He concluded that his decisions on what work to attempt “were determined to an embarrassingly great extent by considerations of clerical feasibility, not intellectual capability.”

This 85% of his research time, devoted to performing routine clerical or mechanical operations ranging from calculating and data plotting to collect information, are tasks that in principle could be performed better and faster by a computer. Computers, he believed, would rescue the human mind from its enslavement by mundane detail. Humans and machines were destined to unite in an almost mystical partnership, with computers handling rote algorithms while people provided creative impulses. The hope, he said, was that “the resulting partnership will think as no human brain has every thought and process data in a way not approached by the information-handling machines we know today.” Lick found this vision of human-computer symbiosis so compelling that standard psychology could no longer compete.

Thus he switched fields, becoming an active member of the computer community. In March 1960 Lick published a seminal paper—Man-Computer Symbiosis, where he formulated a new vision of computing. He described a machine that humans could relate to in the manner of “a colleague whose competence supplements your own”—a friend who could help when the problems got too hard to think through in advance. Such problems “would be easier to solve” he wrote, “and they could be solved faster, through an intuitively guided trial-and-error procedure in which the computer cooperated, turning up flaws in the reasoning or revealing unexpected turns in the solution.”

Real-time computers were still a rarity in the 1960s, and far too expensive for personal use. Therefore, Lick concluded, the most efficient way to use this technology was to have the computer “divide its time among many users.” This certainly was not an original idea; such “time-sharing systems” were already under development at MIT and elsewhere. Lick however followed that notion to its logical conclusion, describing an online “thinking center” that would “incorporate the functions of present-day libraries.” He foresaw “a network of such centers, connected to one another by wide-band communications lines and to individual users by leased-wire services.” Sounds like ARPANET, yeah?

Lick also saw a desperate need for better ways for the interaction between human-computer. Punch cards and printouts were, he wrote, hopelessly impoverished relative to human communication via sight, sound, touch, and even body language. Lick proposed a solution: a desk-sized console that would function much like today’s personal computer, equipped with voice and handwriting recognition. He described a display surface as “approaching the flexibility and convenience of the pencil and doodle pad or the chalk and blackboard.”

Lick pointed out the need for reference works distributed via cheap, mass-produced “published memory”; data storage that could access items by content, and not just by names or keywords; and languages that would allow you to instruct the computer by giving it goals, instead of step-by-step procedures. He also revealed his mixed feelings about artificial intelligence, then in its infancy. He saw it as being potentially very useful but knew far too much about the brain and its complexities to believe that computers would soon be surpassing humans.

In October 1962 Lick became the first director of the Information Processing Techniques Office (IPTO) of the Advanced Research Projects Agency (ARPA) of the Department of Defense and launched a research program after his vision of man-computer symbiosis, including hardware and software requirements for such a symbiosis. The Pentagon had formed ARPA five years earlier in the aftermath of the USSR’s Sputnik as a fast-response research agency, charged with making sure the United States was never again caught flat-footed. Now, ARPA wanted to set up a small research program in “command and control”. This was a critical matter in the nuclear age and was obviously going to involve computers. And once ARPA director Jack Ruina heard Lick expound upon his vision of interactive, symbiotic computing, he knew he had found the right person to lead the effort. Lick was being offered an opportunity to spend big money (over 10 million USD) in pursuit of his vision of human-computer symbiosis. The IPTO program, initiated by Lick turned out to be very successful, so much so that it has become by now a model for other government-sponsored research programs.

In IPTO Lick formed scattered groups of researchers around the country who already shared his dream, and nurture their work with ARPA funding. The first major project, supported by Lick, was Project MAC at MIT, founded with Lick’s encouragement as a large-scale experiment in timesharing and as a prototype for the computer utility of the future. MAC (the name stood for both “Multi-Access Computer” and “Machine-Aided Cognition”) would also incorporate Marvin Minsky‘s Artificial Intelligence (AI) Laboratory. Other major sites included Stanford, where Lick was funding a new AI group under time-sharing inventor John McCarthy; Berkeley, where he had commissioned another demonstration of time-sharing; Rand Corp., where he was supporting the development of a “tablet” for freehand communication with a computer; and Carnegie Tech, where he was funding Allen Newell, Herbert Simon and Alan Perlis to create a “center of excellence” for computer science. Lick had also taken a chance on a soft-spoken visionary he barely knew, namely Douglas Engelbart, whose ideas on augmenting the human intellect with computers closely resembled his own and who had been thoroughly ignored by his colleagues. With funding from Lick, and eventually from NASA as well, Engelbart would go on to develop the mouse, hypertext, onscreen windows, and many other features of modern software.

Lick wanted to create a community in which widely dispersed researchers could build on one another’s work instead of generating incompatible machines, languages, and software. He broached this issue in an April 1963 memo to “Members and Affiliates of the Intergalactic Computer Network”. The solution was to make it extremely easy for people to work together by linking all of ARPA’s time-sharing computers into a national system. He wrote: “If such a network as I envisage nebulously could be brought into operation, we would have at least four large computers, perhaps six or eight small computers, and a great assortment of disc files and magnetic tape units—not to mention the remote consoles and teletype stations—all churning away.”

Again to close to what we now call the Internet. This time however Lick didn’t stop there. Clearly enamored by the idea, he spent most of the rest of the memo sketching out how people might use such a system. He described a network in which software could float free of individual machines. Programs and data would live not on an individual computer but on the Net.

A major project on which Lick worked at BBN was a study of future libraries, granted to him by the Council on Library Resources. It was intended to be a five-year effort beginning in November 1961, but it lasted only two years because Lick left BBN in 1962 to become director of IPTO, and even his long-distance supervision of the project had to be terminated a year later. The final report on the project, completed in January 1963, was deemed by the council to be an important contribution deserving of publication in book form. The book Libraries of the Future, published in 1965 by MIT Press, presents a vision of future libraries based on Lick’s vision of man-computer symbiosis.
The first half of the book is similar in structure to his earlier paper. After limiting the scope of “Libraries” to the body of documents that could be stored in digital form without loss of value and estimating its current size, Lick presents a detailed analysis of the intellectual processes involved in the acquisition, organization, and use of knowledge. This is followed by a description of the structure and usage of the “procognitive systems” he envisioned, capable of searching the body of documents under user control. Finally, Lick outlines, as in his earlier paper, a research program intended to bring about his vision. The second half of the book reports on the initial steps of the research program carried out as part of the library project.

In 1964 Lick completed his two-year tour of duty at ARPA and became a consultant to the director of research of IBM. At ARPA, program managers traditionally moved on after a year or two to give someone else a chance, and Lick was no exception. But in September 1964, when he left ARPA for the IBM research laboratory, he took care to find a successor who shared his vision. His choice was Ivan Sutherland, a 26-year-old computer graphics genius from MIT’s Lincoln Lab whose doctoral project, Sketchpad, was the ancestor of today’s computer-aided design software.
Lick’s influence would continue to be felt at ARPA for more than a decade. Sutherland’s successor in 1966 would be Robert Taylor, who shared with Lick a background in psychology and who was probably Lick’s most enthusiastic convert to the symbiosis vision. It was Taylor who would inaugurate the actual development of Lick’s proposed computer network, which began operation in 1969 as the ARPAnet and ultimately evolved into the Internet. And it was Taylor who went on to head the computer group at Xerox’s Palo Alto Research Center (PARC), where, during the 1970s, researchers turned Lick’s notion of symbiosis into a working system. When Taylor left ARPA in 1969, he handed the reins to ARPAnet architect Larry Roberts, another computer graphics maven, who had become intrigued with networking after a late-night bull session with Lick.
So, in 1966 Lick returned to MIT to direct Project MAC and as a professor of electrical engineering and as director of Project MAC, the research laboratory he had been instrumental in establishing in 1963 and which became eventually the present Laboratory for Computer Science. In 1974 he took a year’s leave of absence to return to Washington with the Department of Defense, again as director of the IPTO. Licklider returned to MIT from government service in 1975 and remained there until his retirement in 1985 when he became an emeritus professor.

Biography of Joseph Licklider

[Joseph Carl Robnett Licklider (known as Lick) was born on 11 March 1915, in St. Louis, Missouri, USA. He was the only child of Joseph Parron Licklider (1873-1962), a Baptist minister and teacher, and Margaret Robnett Licklider (1881-1977), a homemaker.

The little Robnett, as he was known as a boy, was a happy, energetic boy with a lively sense of fun, and early on displayed an insatiable curiosity and a love of all things technological, especially cars. At 15, he bought an old junker and took it apart, again and again, trying to figure out its inner workings. For years thereafter, he refused to pay more than $50 for a car; whatever shape it was in, he could fix it up and make it go.

After graduating from the public school system of University City, Mo., in June 1932, Lick enrolled at Washington University in St. Louis, where in 1937 he obtained a triple degree in physics, math, and psychology, and an MA degree in psychology in 1938. In 1938 he entered the University of Rochester in New York, from which he received a Ph.D. in psychology in 1942. For his doctoral dissertation, he made the first maps of neural activity on the auditory cortex, pinpointing the regions crucial to our ability to hear a musical pitch.

Lick’s professional career began in 1942 when he joined Harvard’s Psycho-Acoustics Laboratory. It was wartime and the Army Air Force was funding a team of psychologists at that lab to attack the problem of noise. The USA had just entered World War II, and aircraft crews were finding it difficult to function amid the overwhelming din of the engines. Lick devised a method for artfully distorting radio transmissions to emphasize consonants over vowels and thus make words stand out against a background of radio static and mechanized cacophony. Lick’s wartime research was presented after the end of the war in a series of papers, many of them co-authored with various colleagues. His discovery led to significant equipment improvements, for which he was granted a patent, as well as the Biennial Award for Outstanding Contributions to Acoustics of the Acoustical Society of America in 1950. In 1945 he received a non-tenure appointment as a lecturer at Harvard University, where he remained until 1950.

Lick married on 20 January 1945 to Alberta Louise Carpenter (b. 1919). They had two children: Tracy Robnett, born in 1947, and Linda Louise, born in 1949, in Arlington, Mass.

In 1950 Lick was appointed as an associate professor at the MIT (Massachusetts Institute of Technology) and remained there for seven years as director of the Acoustics Laboratory. In his second year at MIT, he was retained by the U.S. Air Force laboratories as a consultant in the fields of pitch perception and the intelligibility of speech. During the administration of President Dwight Eisenhower, Licklider was an adviser to the Research and Development Board (1953-1954), the Office of the Secretary of Defense (1954-1955), the committee on biotechnology and human research at the National Aeronautics and Space Administration, and the Commission on Science and Technology. In recognition of his contributions to psychoacoustics and his distinguished government service, Licklider was elected president of the Acoustical Society of America in 1958.

Developing in the 1950s his theories of perception Lick used analog equipment. He found out, however, that analog computers were not flexible enough to help him in his theory-building effort. This disappointment with analog computers marks the beginning of his love affair with digital computers as modeling tools. Thus he switched to the field of computers and made very important contributions in this field.

Lick seems to have been one of those rare beings who genuinely didn’t care who got the credit, so long as the goal was accomplished. He was remembered as “extremely intelligent, intensely creative, and hopelessly generous” with his ideas.

Let’s look at the memories of one of his colleagues and friends—the president of Columbia University William McGill:
“Lick was probably the most gifted intuitive genius I have ever known. Whenever I would finally come to Lick with the proof of some mathematical relation, I’d discover that he already knew it. He hadn’t worked it out in detail, he just knew it. He could somehow envision the way information flowed, and see relations that people who just manipulated the mathematical symbols could not see. It was so astounding that he became a figure of mystery to all the rest of us: How the hell does Lick do it? How does he see these things?… Talking with Lick about a problem, amplified my own intelligence by about thirty IQ points.”

Lick was also a gifted and prolific writer, as his bibliography lists more than 100 formal publications, in addition to laboratory reports. In addition to the National Academy of Sciences, he was a member of the American Academy of Arts and Sciences, the New York Academy of Sciences, and the Washington Academy of Sciences, and a fellow or member of a large number of other professional societies. He was also the recipient of the 1965 Franklin V. Taylor Award of the Society of Engineering Psychologists, the 1968 Outstanding Alumni Award of Washington University, and the 1990 Commonwealth Award for Science and Invention.

By the time microcomputers hit big in the early 1980s, Lick was pushing 70. Just as his ideas of personal computing and networking were coming to fruition, he was losing the vigor to contribute significantly to the cause. His hands had a noticeable tremor—a condition that would eventually be diagnosed as Parkinson’s disease. His allergies had crossed the line into asthma, and he never went anywhere without an inhaler. In the end, it was asthma that finally caught up with him: An attack left his brain without oxygen for too long, and Lick died without regaining consciousness on 26 June 1990, at Symmes Hospital in Arlington, Massachusetts.

 

Three people can be credited as inventors of packet-switched networks, thus laying foundations for the Internet: Paul Baran, Leonard Kleinrock, and Donald Davies. Little known to these men, at the time of inventing these networks, was exactly how much of an impact it would play on mankind. Arguably their impact can be compared to the entire history of telecommunications. Could you imagine a world without search engines, blog hosting, and social media, or more importantly, could these men imagine a world with these aspects in it?

The Welsh Donald Watts Davies was born in Treorchy in the Rhondda Valley, Wells, on 7 June 1924, in the family of a clerk at a coal mine. When his father died a few months later, his mother moved Donald and his twin sister to her hometown of Portsmouth, where he went to school. He went on to get a BSc degree in physics at Imperial College, London, which he received in 1943, then took another first-class degree in mathematics, graduating in 1947, both with first-class honors.

During his last year at university, he attended a lecture by John Womersley, superintendent of the mathematics division of the National Physical Laboratory (NPL), about the ACE digital computer, which was being developed there. Excited by the potential of the new technology, Davies immediately applied to join the group, and in September 1947 he joined the laboratory as a member of the small team, which was led by Alan Turing.

The group’s work, based on Turing’s design, eventually led to the development of the Pilot ACE computer, which ran its first program in May 1950, and was one of the first electronic stored-program digital computers in the world. Along with Max Newman, Jim Wilkinson, and others, Davies had played an important part in the detailed design and development of the machine, and its successor, the full-scale ACE computer.

As computer development moved from the laboratory to industry, Davies’s interests widened to include the purposes for which computers could be used. Davies worked for a while on applications such as road traffic simulation and machine translation (in 1958 he initiated a project to use a computer to translate technical Russian into English).

In 1963 he was appointed technical manager of the advanced computer techniques project, responsible for government support for the British computer industry. The key new project was the development of an idea he had originated in 1965: that to achieve communication between computers a fast message-switching communication service was needed, in which long messages were split into chunks sent separately, so as to minimize the risk of congestion.
Davies said he had realized that it was inefficient for a computer to send an entire file to another computer in an uninterrupted stream of data, chiefly because computer traffic is ‘bursty’ with long periods of silence. The stream must be broken up into chunks (which he called packets), and the technique became known as packet-switching. As he later wrote: “So, in November 1965, I conceived the use of a purpose-designed network employing packet switching in which the stream of bits is broken up into short messages, or packets, that find their way individually to the destination, where they are reassembled into the original stream”.

So Davies initiated the terms packet and packet switching into the network terminology (which is much catchier than Baran’s distributed adaptive message block switching). Davies had considered many possibilities—block, unit, segment, etc., before deciding on a packet as a sort of small package. And as he later told Baran: “Well, you may have got there first, but I got the name.”

Davies’ team presented its paper at a 1967 conference in Tennessee, USA, where Lawrence Roberts of the Advanced Research Projects Agency (ARPA) of the U.S. Department of Defense presented a design for creating a computer network. In the United States, this led to the development of ARPANET, the prototype of the Internet.

Davies’ later work concentrated on the security of data. He undertook security studies for teleprocessing systems, financial institutions, government agencies, and suppliers.

Davies received the British Computer Society Award in 1974. He was appointed a Distinguished Fellow of the British Computer Society in 1975, a CBE in 1983, and a Fellow of the Royal Society in 1987. His books included “Communication Networks for Computers” in 1973, “Computer Networks and their Protocols” in 1979, and “Security for Computer Networks” in 1984.

Donald Davies died on 28 May 2000.

Three people can be credited as inventors of packet-switched networks, thus laying the foundations for the Internet: Paul Baran, Leonard Kleinrock, and Donald Davies.

In 1959 Paul Baran (1926-2011), a Litvak (Lithuanian Jew), whose family emigrated to the USA when he was a child (interestingly, Leonard Kleinrock was also born to a Jewish-American family), obtained his Master’s degree in Engineering from UCLA and began working for the Research And Development (RAND) research organization in the same year. RAND was founded in Santa Monica, California, soon after WWII to help maintain the unique system analysis and operations research skills developed by the US military to manage the unprecedented scale of planning and logistics during that global conflict.

The US Air Force had recently established one of the first wide area computer networks for the SAGE radar defense system and had an increasing interest in reliable and survivable, wide area communications networks, so they could reorganize and respond after a nuclear attack, diminishing the attractiveness of a first strike option by the main enemy—Soviet Union.

Relying on his experience in the radio networks, Baran began an investigation into the development of survivable communications networks, the results of which were first presented to the Air Force in the summer of 1961, and then he wrote a series of eleven comprehensive papers, which appeared in a series of RAND studies, published between 1960 and 1962, and then in a book, titled On Distributed Communications in 1964.

Baran’s study describes a remarkably detailed architecture for a distributed, survivable, packet-switched communications network. The network is designed to withstand almost any degree of destruction to individual components without loss of end-to-end communications. Since each computer could be connected to one or more other computers, Baran assumed that any link of the network could fail at any time, and the network, therefore, had no central control or administration (see the lower scheme).

Using a mini-computer, Baran and his team developed simulation programs to test the basic connectivity of an array of nodes with varying degrees of linking. That is, a network of n-ary degree of connectivity would have n links per node. The simulation randomly destroyed nodes and subsequently tested the percentage of nodes that remained connected. The result of the simulation revealed that networks where n>=3 had a significant increase in resilience against even as much as 50% node loss. Baran’s conviction gained from the simulation was that redundancy was the key.

Baran’s work was accepted by the US Air Force for implementation and testing but was neglected. His series of papers and books however then influenced Larry Roberts and Kleinrock to adopt the technology for the development of the ARPANET network a few years later. Actually, the ARPANET was never intended to be a survivable communications network, but some people still maintain the myth that it was. Instead, the resilience feature of a packet-switched network, that uses link-state routing protocols is something we enjoy today in some part from the research done to develop a network that could survive a nuclear attack.

While working at the RAND, in addition to his innovation in networking products, Baran also created the first metal detector, used today in all airports and many other security points.

Paul Baran left RAND to become an entrepreneur and private investor in the early 1970s, and founded a couple of telecommunication companies—Metricom, Com21.com, and co-founded the Institute for the Future.

Baran holds several patents and has received numerous professional honors, including the IEEE Alexander Graham Bell Medal, the Marconi International Fellowship Award, and the National Medal of Technology and Innovation.

Paul Baran was the finest gentleman and an extremely creative man. However, he believed that innovation was a “team process” and he didn’t seek credit for himself. He once said: “Many of the things I thought possible would tend to sound like utter nonsense, or impractical depending on the generosity of spirit in those brought up in an earlier world.”

Biography of Paul Baran

Paul Baran was born in the town of Grodno (then in Poland, now in Belarus) as Павел Баранов (Yiddish given name “Pesach”, one of the most commonly observed Jewish holidays, usually in April) on 29 April 1926, as the youngest of three children (Paul had a sister, Harriet (1915-1995), and a brother, Herbert (1919-1966)) in the Jewish family of Мойше (Моррис) Баран (Morris “Moshe” Baran) (1884–1979) and Хана-Фейга (Анна) Серейская (Anna Seren-Baran) (1893-1972) (baran is a Slavic word for ram (male sheep)). In May 1928, the Baran family moved to the United States, first to Boston, where Moshe found work in a shoe factory, then to Philadelphia, where he established a small grocery store. As a child, little Paul delivered groceries for his father in his little red wagon.

In 1949 Baran received his bachelor’s degree in electrical engineering from Drexel University in Philadelphia and immediately was hired by the Eckert-Mauchly Computer Company as a technician on the world’s first commercial computer, the Univac. In 1950 he went to the Raymond Rosen Engineering Products Company, where he designed the first telemetering equipment for Cape Canaveral. In 1955 Baran married Evelyn Murphy, moved to Los Angeles, and joined the Hughes Aircraft Company, where he worked for 4 years, at the same time preparing for his Master’s degree.

After his grounding work for survivable communications networks in the early 1960s, in 1968, Baran founded the Institute for the Future and was then involved in other networking technologies developed in Silicon Valley. Baran participated in a review of the NBS proposal for a Data Encryption Standard in 1976. In the early 1980s, Baran founded PacketCable Inc., “to support impulse-pay television channels, locally generated videotex, and packetized voice transmission.” He founded Telebit after conceiving its discrete multitone modem technology in the mid-1980s. In 1985, Baran founded Metricom, the first wireless Internet company, which deployed Ricochet, the first public wireless mesh networking system. In 1992, he also founded Com21, an early cable modem company. After Com21, Baran founded and was president of GoBackTV, which specializes in personal TV and cable IPTV infrastructure equipment for television operators. Most recently, he founded Plaster Networks, providing an advanced solution for connecting networked devices in the home or small office through existing wiring.

Baran extended his work in packet switching to wireless-spectrum theory, developing what he called “kindergarten rules” for the use of wireless spectrum. In addition to his innovation in networking products, he is also credited with inventing the first doorway gun detector.

Paul Baran was a genius, but also an extremely modest man. He had told the Times in 1990 “The process of technological development is like building a cathedral. Over the course of several hundred years, new people come along and each lays down a block on top of the old foundations, each saying, I built a cathedral… If you are not careful you can con yourself into believing that you did the most important part.”

His son David Baran remembered that his father had shown him a paper written in 1966 that speculated about what people would do with telecommunication networks in the future. “It spelled out this idea that by the year 2000 the people would be using online networks for shopping and news,” he said. “It was an absolute lunatic fringe idea.”

Paul Baran died of lung cancer on 28 March 2011, in Palo Alto, California. His wife, Evelyn, died in 2007. In addition to his son, David, of Atherton, California, he was survived by three grandchildren.