Radia Perlman

Inventor of the spanning tree protocol

• Born: 1951
• Place of Birth: Portsmouth, Virginia

Primary Company/Organization: Sun Microsystems

Introduction

Although she dislikes the title, software engineer and inventor Radia Perlman is widely known as "the mother of the internet" for her design of the spanning-tree protocol (STP), which has kept the internet accessible through networking even as it has continued to expand, as well as TRILL (for Transparent Interconnection of Lots of Links), a more sophisticated protocol that fixed problems with STP. She is also a pioneer in tangible computing and is responsible for the development of link-state routing. In the field of internet security, Perlman has developed sabotage-proof networks, certificate revocation, and password protection. She holds more than one hundred patents, approximately half of them in conjunction with Sun Microsystems. Her textbooks have become required reading for both students and professionals.

Early Life

Radia Perlman was born in Portsmouth, Virginia, in 1951, but she spent most of her childhood in New Jersey. Her father, Julius Perlman, was a radar technician for the US Navy, and her mother, Hope Sonne Perlman, worked as a civilian computer programmer. Thus, both parents were interested in engineering, even though they discouraged their daughter from engaging in hands-on experimentation. Perlman grew up with a strong interest in both mathematics and science. She has continued to insist that she hates technology, despite spending her entire professional life in the field of computer technology. She was also an accomplished musician, playing both piano and French horn; composed music; wrote; and drew.

In 1969, Perlman enrolled at the Massachusetts Institute of Technology (MIT) in Cambridge and discovered computer programming. Like learning music, programming required one to master a new language. As part of her undergraduate program, she worked in the Logo Lab at the MIT Artificial Intelligence Laboratory (now the MIT Computer Science and Artificial Intelligence Laboratory), studying the Logo educational programming language. Under the guidance of South African–born educator and computer scientist Seymour Papert, she developed the TORTIS (for Toddler's Own Recursive Turtle Interpreter System) programming system, a child-friendly version of Logo that was designed to enable young, preliterate children to learn computer programming.

Perlman earned her bachelor's degree in mathematics in 1973. She spent the years between 1974 and 1976 working on her master's degree and redesigning TORTIS. She worked with children, some as young as three years old, teaching them to program the turtle robot (an educational robot commonly used in teaching computer science and mechanical engineering) by pressing buttons and moving physical objects on a terminal. As a result of that work, Perlman came to be considered a pioneer of the field of tangible computing, in which the programmer constructs a computer program by manipulating physical objects rather than by typing code.

Perlman completed her master's degree in 1976 and received her doctorate from MIT in 1988. Her PhD thesis, called Network Layer Protocols with Byzantine Robustness, dealt with network failures that occur in response to malicious activities.

Life's Work

Perlman's first job after completing her master's work at MIT was as a software designer with Bolt, Beranek, and Newman, a company that developed networking equipment for use by the US government. In 1980, while giving a speech on network routing, she was recruited by the Digital Equipment Corporation (DEC). After starting her work there, she was asked if she could solve the problem the company was having in getting its computers to communicate with one another. In less than a week, Perlman invented the spanning-tree protocol (STP), a system of algorithms that work behind the scenes to connect Ethernet switches, the bridges that form a local area network.

Before Perlman invented STP, Ethernet technology was confined to use by small networks within a limited area. With STP, legitimate connections on the network were recognized, and anything beyond the tree itself was disabled. The protocol has been identified as the “heart” of the Ethernet, allowing computers to connect to the internet, which much of the world had begun taking for granted by the twenty-first century. Greg Papadopoulos, who later worked with Perlman at Sun Microsystems, described STP as a road map for moving traffic in the virtual world of the internet.

Perlman's quirky sense of humor is evident in her work. She penned the poem “Algorhyme,” patterned on Joyce Kilmer's “Trees,” to explain the spanning-tree protocol, and her son later set it to music. Perlman's STP has been embraced by the International Organization for Standardization (ISO) as well as the Institute of Electrical and Electronics Engineers Standards Association (IEEE-SA).

In 1993, Perlman accepted a job with the software company Novell, working on information exchange and security. Four years later, she moved to Sun Microsystems, where she specialized in network security. Of the more than one hundred patents Perlman holds, some fifty of them arose from her thirteen years at Sun.

In 2004, in order to solve problems encountered by STP as internet technology became more sophisticated, Perlman invented a standard known as TRILL (for Transparent Interconnection of Lots of Links). Unlike STP, TRILL is designed to optimize available bandwidth by taking the shortest path available and making use of multipathing. It makes use of link-state routing, which is one of two major protocols used to connect computers to networks and the internet. TRILL is credited with helping keep the internet stable, scalable, and robust.

Although she has become widely identified as the “mother of the Internet,” Perlman rejects the label, insisting that there are a number of individuals responsible for creating and maintaining the internet. She also does not like the gendered nature of the title, arguing that gender should not be an issue when discussing someone's life work.

Sun Microsystems was acquired by Oracle in 2009. After spending thirteen years at the company, Perlman decided to leave. She joined the Intel Corporation as an Intel Fellow in 2010; the following year, she became the company's director of network security technology. In 2014, Perlman joined the EMC Corporation as the company's first Industry Fellow. In September 2016, EMC joined with Dell in what was then the largest technology merger in history, becoming Dell Technologies. Perlman was a fellow at Dell EMC, a Dell Technologies company, as of 2024.

Perlman has extended her knowledge to students through classroom teaching, and she has taught at MIT, Harvard University, and the University of Washington. In 1997, Prentice Hall began publishing the Radia Perlman Series in Computer Networking and Security, beginning with James Solomon's Mobile IP: The Internet Unplugged.

In the January 15, 1992, issue of Data Communications magazine, Perlman was recognized as one of the twenty most influential people in the industry. She was again recognized by the same publication in the January 15, 1997, issue, becoming the only figure in the industry to be so named in two issues. In 2004, the Silicon Valley Intellectual Property Law Association (SVIPLA) designated Perlman as its Silicon Valley Inventor of the Year.

Perlman is considered to be one of the most significant contributors to the field of women in technology. In recognition of those contributions, the prestigious Royal Institute of Technology in Sweden awarded her an honorary doctorate in 2000 and the Anita Borg Institute awarded Perlman its Women of Vision Award for Innovation in 2005, the first year the awards were given. In 2006, the Advanced Computing Systems Association (USENIX) honored Perlman with a lifetime achievement award. In 2012, she was recognized by the Association for Computing Machinery's Special Interest Group on Data Communication (SIGCOMM) for her work on internet routing and bridging protocols. She was inducted into the Internet Hall of Fame in 2014 and the National Inventors Hall of Fame in 2016.

Personal Life

Perlman has maintained her base in Washington, where she lives with her partner, Charlie Kaufman. She has two children and several grandchildren. Her son, Ray, is an engineer. Her daughter, Dawn, is a musician. She continues to play piano.

Bibliography

Barlas, Pete. “The 'Mother' of the Internet.” Investor's Business Daily 9 Feb. 2006: A4. Print.

Boudreau, John. “Technology's Women of Vision.” San Jose Mercury News 19 Oct. 2005: n. pag. Newspaper Source. Web. 28 Sept. 2015.

Bouquet, Cyril, et al. "How Tech Pioneer Radia Perlman Overcame Bias to Invent a Core Component of the Internet." Fast Company, 18 Mar. 2021, www.fastcompany.com/90615239/radia-perlman-internet-pioneer-gender-bias. Accessed 3 Aug. 2021.

Diffie, Whitfield. “Information Security: 50 Years Behind, 50 Years Ahead.” Communications of the ACM Jan. 2008: 55–57. Academic Search Complete. Web. 28 Sept. 2015.

Kaufman, Charlie, Radia Perlman, and Michael Speciner. Network Security: Private Communication in a Public World. 2nd ed. New York: Prentice, 2002. Print.

“The Many Sides of Radia Perlman.” Intel Free Press. Intel, 20 Apr. 2011. Web. 12 Aug. 2012.

Perlman, Radia. Interconnections: Bridges, Routers, Switches, and Internetworking Protocols. 2nd ed. Boston: Addison, 2000. Print.

Perlman, Radia. "Radia Perlman: Don't Call Me the Mother of the Internet." Interview by Rebecca J. Rosen. Atlantic. Atlantic Monthly, 3 Mar. 2014. Web. 28 Sept. 2015.

Perlman, Radia. "Why IEEE Fellow Radia Perlman Hates Technology." Interview by Alexander Pasik. ITworld. IDG, 22 Apr. 2011. Web. 28 Sept. 2015.

"Piano and Protocols: The Story of Inventor Radia Perlman." National Inventors Hall of Fame, www.invent.org/blog/inventors/spanning-tree-protocol. Accessed 8 Mar. 2024.

Rosenheim, Dan. "An Unassuming Giant in Her Field: Radia Perlman's Work Speaks Volumes." Internet Hall of Fame, 8 Mar. 2021, www.internethalloffame.org/2021/03/08/unassuming-giant-her-field-radia-perlmans-work-speaks-volumes/. Accessed 8 Mar. 2024.