View source for Biography:Radia Perlman

{{short description|American software designer and network engineer}}
{{Infobox scientist
| image                   = Radia Perlman 2009.jpg
| birth_date              = {{Birth date and age|1951|12|18}}
| birth_place             = Portsmouth, Virginia, US
| field                   = Computer Science
| work_institution        = [[Company:Intel|Intel]]
| alma_mater              = MIT
| doctoral_advisor        = [[Biography:David D. Clark|David D. Clark]]
| thesis_title            = Network layer protocols with Byzantine robustness
| thesis_year             = 1988
| thesis_url              = http://dspace.mit.edu/handle/1721.1/14403
| known_for               = Network and security protocols; computer books
}}

'''Radia Joy Perlman''' ({{IPAc-en|ˈ|r|eɪ|d|i|ə}};<ref>{{cite web|url=https://www.youtube.com/watch?v=LgbhWUVx_ts&t=38s|title=Making Data Flow: The Radia Perlman Story|work=National Inventors Hall of Fame|date=May 9, 2016|access-date=September 2, 2022}}</ref> born December 18, 1951) is an American computer programmer and network engineer. She is a major figure in assembling the networks and technology to enable what we now know as the internet. She is most famous for her invention of the Spanning Tree Protocol (STP), which is fundamental to the operation of [[Network bridge|network bridge]]s, while working for [[Company:Digital Equipment Corporation|Digital Equipment Corporation]], thus earning her nickname "Mother of the Internet".<ref name="SPT">{{cite web |title=Radia Perlman Spanning Tree Protocol|url=https://lemelson.mit.edu/resources/radia-perlman |website=NAE Website |access-date=20 July 2021}}</ref> Her innovations have made a huge impact on how networks self-organize and move data. She also made large contributions to many other areas of network design and standardization: for example, enabling today's [[Link-state routing protocol|link-state routing protocol]]s, to be more robust, scalable, and easy to manage. 

Perlman was elected a member of the National Academy of Engineering in 2015 for contributions to Internet routing and bridging protocols.<ref>{{cite web |title=Dr. Radia J. Perlman |url=https://www.nae.edu/130123/Dr-Radia-J-Perlman |website=National Academy of Engineering |access-date=2023-06-30}}</ref> She holds over 100 issued patents.  She was elected to the Internet Hall of Fame in 2014, and to the National Inventors Hall of Fame in 2016.<ref>{{cite web |title=Radia Perlman |url=https://www.internethalloffame.org/inductees/radia-perlman |website=Internet Hall of Fame |access-date=2023-06-30}}</ref><ref>{{cite web |title=Radia Perlman: Robust Network Routing and Bridging |url=https://www.invent.org/inductees/radia-perlman |date=2016 |publisher=National Inventors Hall of Fame |access-date=2023-06-30}}</ref>  She received lifetime achievement awards from [[Organization:USENIX|USENIX]] in 2006 and from the [[Organization:Association for Computing Machinery|Association for Computing Machinery]]’s SIGCOMM in 2010.<ref>{{cite web |title=Flame Award |date=December 6, 2011 |url=https://www.usenix.org/about/awards/flame |publisher=USENIX |access-date=2023-06-30}}</ref><ref>{{cite web |title=SIGCOMM Award Recipients |url=http://www.sigcomm.org/awards/sigcomm-awards |publisher=ACM SIGCOMM |access-date=2023-06-30}}</ref>

More recently she has invented the [[TRILL (computing)|TRILL]] protocol to correct some of the shortcomings of spanning trees, allowing Ethernet to make optimal use of bandwidth. As of 2022, she was a Fellow at [[Company:Dell Technologies|Dell Technologies]].<ref name=amazon-bio>{{cite book |title=Network Security: Private Communication in a Public World (Prentice Hall Series in Computer Networking and Distributed Systems) 3rd Edition |isbn=978-0136643609 |last1=Kaufman |first1=Charlie |last2=Perlman |first2=Radia |last3=Speciner |first3=Mike |last4=Perlner |first4=Ray |date=September 15, 2022 |publisher=Addison-Wesley }}</ref>

== Early life ==
Perlman was born in 1951, Portsmouth, Virginia. She grew up in Loch Arbour, New Jersey.<ref>[https://www.newspapers.com/newspage/516527127/ "Music Winners Feted"], ''Red Bank Register'', December 27, 1968. Accessed September 20, 2021. "Mrs. Benjamin Nebman, 1308 Edgewood Ave., hosted a party in her home to honor her students Adrienne Wigdortz, Wanamassa, and Radia Perlman, Loch Arbour, who were two of the winners of the Monmouth Arts Foundation Merit Award for piano."</ref> She is Jewish.<ref>{{Cite web|url=https://jwa.org/people/perlman-radia|title=Radia Perlman}}</ref> Both of her parents worked as [[Engineering:Engineer|engineer]]s for the US government. Her father worked on [[Engineering:Radar|radar]] and her mother was a mathematician by training who worked as a computer programmer. During her school years Perlman found math and science to be “effortless and fascinating”, but had no problem achieving top grades in other subjects as well. She enjoyed playing the piano and French horn. While her mother helped her with her math homework, they mainly talked about literature and music. But she didn't feel like she fit underneath the stereotype of an "engineer" as she did not break apart computer parts <ref>{{cite journal| last = Salim| first = Nancy| date = 18 October 2010| title = Radia Perlman: Don't Call Me the Mother of the Internet| url = https://www.theatlantic.com/technology/archive/2014/03/radia-perlman-dont-call-me-the-mother-of-the-internet/284146/| journal = The Atlantic | access-date = 20 March 2018}}</ref>

Despite being the best science and math student in her school it was only when Perlman took a programming class in high school that she started to consider a career that involved computers. She was the only woman in the class and later reflected "I was not a hands-on type person. It never occurred to me to take anything apart. I assumed I'd either get electrocuted, or I'd break something".<ref>{{cite journal| last = Salim| first = Nancy| date = 18 October 2010| title = Meet the Mother of the Internet| journal = IEEE Women in Engineering Magazine| volume = 4| issue = 2| pages = 10–12| doi =  10.1109/MWIE.2010.938214| s2cid = 32207039}}</ref> She graduated from Ocean Township High School in 1969.<ref>[http://www.digifind-it.com/redbank/_1960-1979/1968/1968-12-12.pdf&page=39 "College's Chamber Chorus Presents Oratorio Tuesday"], ''Red Bank Register'', December 12, 1968. Accessed September 20, 2021. "He will be accompanied by Radia Perlman, also an Ocean Township High School senior."</ref>

== Education ==
As an undergraduate at [[Organization:Massachusetts Institute of Technology|MIT]] Perlman learned programming for a physics class. She was given her first paid job in 1971 as part-time programmer for the [[Logo (programming language)|LOGO]] Lab at the (then) MIT Artificial Intelligence Laboratory, programming [[Software:System software|system software]] such as debuggers. <ref>{{cite journal| last = Salim| first = Nancy| date = 18 October 2010| title = Radia Perlman: Don't Call Me the Mother of the Internet| url = https://www.theatlantic.com/technology/archive/2014/03/radia-perlman-dont-call-me-the-mother-of-the-internet/284146/| journal = The Atlantic | access-date = 20 March 2018}}</ref>

Working under the supervision of [[Biography:Seymour Papert|Seymour Papert]], she developed a child-friendly version of the educational robotics language LOGO, called TORTIS ("Toddler's Own Recursive Turtle Interpreter System"). During research performed in 1974–76, young children—the youngest aged 3½ years, programmed a LOGO educational robot called a Turtle. Perlman has been described as a pioneer of teaching young children computer programming.<ref>{{cite journal |title=Radia Perlman – A pioneer of young children computer programming |author=Leonel Morgado|journal=Current Developments in Technology-Assisted Education |year=2006 |pages=1903–1908 |citeseerx = 10.1.1.99.8166 |display-authors=0}}</ref> Afterwards, she was inspired to make a new programming language that would teach much younger children similar to Logo, but using special "keyboards" and input devices. This project was abandoned because "being the only woman around, I wanted to be taken seriously as a 'scientist' and was a little embarrassed that my project involved cute little kids". MIT media project later tracked her down and told her that she started a new field called [[Tangible user interface|tangible user interface]] from the leftovers of her abandoned project. <ref>{{cite journal| last = Salim| first = Nancy| date = 18 October 2010| title = Radia Perlman: Don't Call Me the Mother of the Internet| url = https://www.theatlantic.com/technology/archive/2014/03/radia-perlman-dont-call-me-the-mother-of-the-internet/284146/| journal = The Atlantic | access-date = 20 March 2018}}</ref> As a math grad at MIT she needed to find an adviser for her thesis, and joined the MIT group at [[Company:BBN Technologies|BBN Technologies]]. There she first got involved with designing network protocols.<ref>{{cite journal| last = Salim| first = Nancy| date = 18 October 2010| title = Radia Perlman: Don't Call Me the Mother of the Internet| url = https://www.theatlantic.com/technology/archive/2014/03/radia-perlman-dont-call-me-the-mother-of-the-internet/284146/| journal = The Atlantic | access-date = 20 March 2018}}</ref> Perlman obtained a B.S. and M.S. in Mathematics and a Ph.D. in Computer Science from MIT in 1988.<ref>{{cite web|title=Radia Perlman|publisher=MIT|url=http://web.mit.edu/invent/iow/perlman.html|archive-url=https://web.archive.org/web/20071208092956/http://web.mit.edu/invent/iow/perlman.html|url-status=dead|archive-date=8 December 2007|access-date=14 October 2012}}</ref>  Her doctoral thesis on routing in environments where malicious network failures are present serves as the basis for much of the work that now exists in this area. <ref name="SPT"/>

When studying at MIT in the late 60s she was one among the 50 or so women students, in a class of about 1,000 students. To begin with MIT only had one women’s dorm, limiting the number of women students that could study. When the men’s dorms at MIT became coed Perlman moved out of the women’s dorm into a mixed dorm, where she became the "resident female". She later said that she was so used to the gender imbalance, that it became normal. Only when she saw other women students among a crowd of men she noticed that "it kind of looked weird".<ref>{{cite journal| last = Salim| first = Nancy| date = 18 October 2010| title = Radia Perlman: Don't Call Me the Mother of the Internet| url = https://www.theatlantic.com/technology/archive/2014/03/radia-perlman-dont-call-me-the-mother-of-the-internet/284146/| journal = The Atlantic | access-date = 20 March 2018}}</ref>

== Career ==
After graduation, she accepted a position with Bolt, Berenek, Newman (BBN), a government contractor that developed software for network equipment. While working for BBN, Perlman made an impression on a manager for Digital Equipment Corp and was offered a job, joining the firm in 1980. During her time working at Digital, she quickly produced a solution that did exactly what the team wanted it to; the Spanning Tree Protocol. It allows a network to deliver data reliably by making it possible to design the network with redundant links. This setup provides automatic backup paths if an active link fails, and disables the links that are not part of the tree. This leaves a single, active path between any pair of network nodes.<ref name="SPT"/> She is most famous for STP, which is fundamental to the operation of [[Network bridge|network bridge]]s in many smaller networks. Perlman is the author of a textbook on networking called “Interconnections: Bridges, Routers, Switches, and Internetworking Protocols” and coauthor of another on network security called “Network Security: Private Communication in a Public World”, which is a now popular college textbook. Her contributions to network security include trust models for Public Key Infrastructure, data expiration, and distributed algorithms resilient despite malicious participants.<ref>{{cite web |title=Patents by Inventor Radia J. Perlman |publisher=Justia Patents |url=http://patents.justia.com/inventor/radia-j-perlman |access-date=29 August 2013}}</ref>

She left Digital in 1993 and joined [[Company:Novell|Novell]]. Then, in 1997 she left Novell and joined [[Company:Sun Microsystems|Sun Microsystems]]. Over the course of her career she has earned some 80 patents, 40 of them while working for Sun Microsystems, where in 2007 she held the title of Distinguished Engineer. <ref>{{cite web |title=Radia Perlman Spanning Tree Protocol |publisher=mit |url=https://lemelson.mit.edu/resources/radia-perlman |access-date=29 August 2013}}</ref> She has taught courses at the [[Organization:University of Washington|University of Washington]], [[Organization:Harvard University|Harvard University]] and MIT, and has been the keynote speaker at events all over the world. Perlman is the recipient of awards such as Lifetime Achievement awards from USENIX and the Association for Computing Machinery’s Special Interest Group on Data Communication (SIGCOMM).<ref>{{Cite web|url=https://internethalloffame.org/inductees/radia-perlman|title=Radia Perlman {{!}} Internet Hall of Fame|website=internethalloffame.org|access-date=2017-11-23}}</ref>

=== Spanning Tree Protocol ===
Perlman invented the spanning tree algorithm and protocol. While working as a consulting engineer at [[Company:Digital Equipment Corporation|Digital Equipment Corporation]] (DEC) in 1984 she was tasked with developing a straightforward protocol that enabled [[Network bridge|network bridge]]s to locate loops in a [[Engineering:Local area network|local area network]] (LAN). It was required that the protocol should use a constant amount of memory when implemented on the network devices, regardless of how large the network was. Building and expanding bridged networks was difficult because loops, where more than one path leads to the same destination, could result in the collapse of the network. Redundant paths in the network meant that a bridge could forward a frame in multiple directions. Therefore loops could cause [[Ethernet|Ethernet frames]] to fail to reach their destination, thus flooding the network. Perlman utilized the fact that bridges had unique 48 bit MAC addresses, and devised a network protocol so that bridges within the LAN communicated with one another. The algorithm implemented on all bridges in the network allowed the bridges to designate one ''root bridge'' in the network. Each bridge then mapped the network and determined the shortest path to the root bridge, deactivating other redundant paths. Despite Perlman's concerns that it took the spanning tree protocol about a minute to react when changes in the [[Network topology|network topology]] occurred, during which time a loop could bring down the network, it was standardized as 802.1d by the [[Organization:Institute of Electrical and Electronics Engineers|Institute of Electrical and Electronics Engineers]] (IEEE). Perlman said that the benefits of the protocol amount to the fact that "you don't have to worry about topology" when changing the way a LAN is interconnected. Perlman has however criticized changes which were made in the course of the standardization of the protocol.<ref>{{cite journal| last = Juneau| first = Lucie| date = 18 Oct 1992| title = Radia Perlman| journal = Network World| volume = 9| issue = 41| page = 103| issn = 0887-7661}}</ref>

From the paper "An Algorithm for Distributed Computation of a Spanning Tree in an Extended LAN":[https://www.it.uu.se/edu/course/homepage/datakom/ht06/slides/sta-perlman.pdf]
© 1985 ACM, copied from ''ACM SIGCOMM Computer Communication Review Volume 15 Issue 4 Sept. 1985'' with permission of the ACM.

:: Algorhyme

:: I think that I shall never see
:: A graph more lovely than a tree.

:: A tree whose crucial property
:: Is loop-free connectivity.

:: A tree which must be sure to span
:: So packets can reach every LAN.

:: First the root must be selected.
:: By ID it is elected.

:: Least cost paths from root are traced.
:: In the tree these paths are placed.

:: A mesh is made by folks like me
:: Then bridges find a spanning tree.

=== Other network protocols ===
Perlman was the principal designer of the [[DECnet]] IV and V protocols, and [[IS-IS]],<ref>{{cite web |last1=Eastlake |first1=Donald |title=TRILL History |url=https://datatracker.ietf.org/meeting/101/materials/slides-101-trill-trill-history-01 |website=IETF Datatracker}}</ref> the [[OSI protocols|OSI]] equivalent of OSPF. She also made major contributions to the Connectionless Network Protocol (CLNP). Perlman has collaborated with Yakov Rekhter on developing network routing standards, such as the OSI Inter-Domain Routing Protocol (IDRP),<ref>{{cite web |title=Inter-Domain Routing Protocol |url=https://www.iso.org/standard/21417.html |website=ISO/IEC}}</ref> the OSI equivalent of BGP. At DEC she also oversaw the transition from [[Distance-vector routing protocol|distance vector]] to [[Link-state routing protocol|link-state routing protocol]]s. Link-state routing protocols had the advantage that they adapted to changes in the network topology faster, and DEC's link-state routing protocol was second only to the link-state routing protocol of the Advanced Research Projects Agency Network (ARPANET). While working on the [[DECnet]] project Perlman also helped to improve the ''intermediate-system to intermediate-system'' routing protocol, known as [[IS-IS]], so that it could route the [[Internet Protocol]] (IP), [[AppleTalk]] and the [[Internetwork Packet Exchange]] (IPX) protocol.<ref>{{cite journal| last = Juneau| first = Lucie| date = 18 Oct 1992| title = Radia Perlman| journal = Network World| volume = 9| issue = 41| page = 103| issn = 0887-7661}}</ref> The [[Open Shortest Path First]] (OSPF) protocol relied in part on Perlman's research on fault-tolerant broadcasting of routing information.<ref>{{cite web|title=Open Shortest Path First |last=Cisco.com |url=http://docwiki.cisco.com/wiki/Open_Shortest_Path_First}}</ref>

Perlman subsequently worked as a network engineer for [[Company:Sun Microsystems|Sun Microsystems]], now [[Company:Oracle Corporation|Oracle]]. She specialized in network and security protocols and while working for Oracle and obtained more than 50 patents.<ref>{{cite journal| last = Salim| first = Nancy| date = 18 October 2010| title = Meet the Mother of the Internet| journal = IEEE Women in Engineering Magazine| volume = 4| issue = 2| pages = 10–12| doi =  10.1109/MWIE.2010.938214| s2cid = 32207039}}</ref>

== Awards ==
* Fellow of the Association for Computing Machinery,(class of 2016)
* National Inventors Hall of Fame induction (2016)
* Internet Hall of Fame induction (2014)<ref>{{cite web|title=Internet Hall of Fame Pioneer Radia Perlman|publisher=[[Organization:Internet Society|Internet Society]]|url=http://internethalloffame.org/inductees/radia-perlman}}</ref>
* SIGCOMM Award (2010)<ref>{{cite web|title=2010 SIGCOM Lifetime Achievement Award given to Radia Perlman|publisher=SIGCOMM|url=http://www.sigcomm.org/awards/sigcomm-awards}}</ref>
* [[Organization:USENIX#USENIX Lifetime Achievement Award|USENIX Lifetime Achievement Award]] (2006)
* Recipient of the first Anita Borg Institute Women of Vision Award for Innovation in 2005<ref>{{cite web|last=Fuller|first=Brian|title=Perlman, Samuelson, Tsao, honored for innovations|url=http://www.eetimes.com/electronics-news/4056086/Perlman-Samuelson-Tsao-honored-for-innovations|work=EETimes|publisher=UBM Electronics|access-date=29 June 2011|date=18 October 2005}}</ref>
* Silicon Valley Intellectual Property Law Association Inventor of the year (2003)<ref>[http://www.svipla.org/inventors "Inventors of The Year"], Silicon Valley Intellectual Property Law Association (SVIPLA). Retrieved 2 July 2013.</ref>
* Honorary Doctorate, Royal Institute of Technology (June 28, 2000)
* Twice named as one of the 20 most influential people in the industry by ''Data Communications'' magazine: in the 20th anniversary issue (January 15, 1992) and the 25th anniversary issue (January 15, 1997). Perlman is the only person to be named in both issues.
*IEEE Fellow in 2008 for contributions to network routing and security protocols<ref>
{{Cite web|
url=https://www.comsoc.org/membership/ieee-fellows/2008|
title = IEEE Fellows 2008 &#124; IEEE Communications Society}}
</ref>
*Fellow of the Association for Computing Machinery, class of 2016<ref>{{citation|title=ACM Recognizes New Fellows|journal=[[Communications of the ACM]]|date=March 2017|volume=60|issue=3|page=23|doi=10.1145/3039921|last1=Cacm Staff|s2cid=31701275}}.</ref>
== Bibliography ==

* {{ cite book | title = Interconnections: Bridges, Routers, Switches, and Internetworking Protocols | edition = 2 | year = 1999 | publisher = Addison-Wesley Professional Computing Series | first = Radia | last = Perlman | isbn = 978-0-201-63448-8 }}
* {{cite book|title = Network Security: Private Communication in a Public World| last1 = Perlman | first1 = Radia | last2 = Kaufman | first2 = Charlie | last3 = Speciner | first3 = Mike | last4 = Perlner | first4 = Ray |  publisher = Addison-Wesley Professional | year = 2022 | isbn = 978-0-13-664360-9 |edition = 3}}

== References ==
{{Reflist}}

== External links ==
* [http://lemelson.mit.edu/resources/radia-perlman Inventor of the Week archive at MIT: Spanning Tree Protocol]


{{DEFAULTSORT:Perlman, Radia}}
[[Category:American computer scientists]]
[[Category:Computer security academics]]
[[Category:Network topology]]

{{Sourceattribution|Radia Perlman}}