Leonard Kleinrock field of work queueing theory
Leonard Kleinrock (born June 13, 1934) is an American computer scientist and Internet pioneer. He is a long-tenured professor at UCLA's Henry Samueli School of Engineering and Applied Science.
In the early 1960s, Kleinrock pioneered the application of queueing theory to model delays in message switching networks in his Ph.D. thesis, published as a book in 1964. He later published several of the standard works on the subject. In the early 1970s, he applied queueing theory to model and measure the performance of packet switching networks. This work played an influential role in the development of the ARPANET. He supervised many graduate students whose later work on the communication protocols for internetworking led to the Internet protocol suite. His theoretical work on hierarchical routing in the late 1970s with student Farouk Kamoun remains critical to the operation of the Internet today.Achievements
Queueing theory
Kleinrock's best-known and most-significant work is on queueing theory, a branch of operations research that has applications in many fields. His thesis proposal in 1961 led to a doctoral thesis at the Massachusetts Institute of Technology in 1962, later published in book form in 1964. In this work, he analyzed queueing delays in Plan 55-A, a message switching system operated by Western Union for processing telegrams. Kleinrock later published several of the standard works on the subject.Internet
Kleinrock published hundreds of research papers, which ultimately launched a new field of research on the theory and application of queuing theory to computer networks. In this role, he supervised the research of scores of graduate students. He disseminated his research and that of his students to wider audiences for academic and commercial use, and organized hundreds of commercial seminars presented by experts and pioneers in the U.S. and internationally. Kleinrock's theoretical work on network design, hierarchical routing, wireless network access, network measurement, network congestion control, and nomadic computing in the late 1970s with student Farouk Kamoun remains critical to the operation of the Internet today.Crocker, Cerf, Postel and others at DARPA, Stanford University and other collaborating groups, developed the conventions – the Request for Comments or RfCs – and the communication protocols for internetworking that led to the Internet protocol suite.
In 1988, Kleinrock was the chairman of a group that presented the report Toward a National Research Network to the U.S. Congress,  concluding that "There is a clear and urgent need for a national research network". Although the U.S. did not build a nationwide national research and education network, this report  influenced Al Gore to pursue the development of the High Performance Computing Act of 1991, which helped facilitate development of the Internet as it is known today. Funding from the bill was used in the development of the 1993 web browser Mosaic at the National Center for Supercomputing Applications (NCSA), which accelerated the adoption of the World Wide Web.
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