Sally Jean Floyd (May 20, 1950 – August 25, 2019) was an American

computer scientist A computer scientist is a person who is trained in the academic study of computer science. Computer scientists typically work on the theoretical side of computation, as opposed to the hardware side on which computer engineers mainly focus (al ...

known for her work on

computer networking A computer network is a set of computers sharing resources located on or provided by network nodes. The computers use common communication protocols over digital interconnections to communicate with each other. These interconnections are ma ...

. Formerly associated with the

International Computer Science Institute The International Computer Science Institute (ICSI) is an independent, non-profit research organization located in Berkeley, California, United States. Since its founding in 1988, ICSI has maintained an affiliation agreement with the University ...

Berkeley, California Berkeley ( ) is a city on the eastern shore of San Francisco Bay in northern Alameda County, California, United States. It is named after the 18th-century Irish bishop and philosopher George Berkeley. It borders the cities of Oakland and Emer ...

, she retired in 2009 and died in August 2019. She is best known for her work on Internet

congestion control Network congestion in data networking and queueing theory is the reduced quality of service that occurs when a network node or link is carrying more data than it can handle. Typical effects include queueing delay, packet loss or the blocking of ...

, and was in 2007 one of the top-ten most cited researchers in computer science."Sally Floyd Wins 2007 SIGCOMM Award"
ICSI, Sept. 2007 (last visited Oct. 7, 2012).

Biography

Born in

Charlottesville, Virginia Charlottesville, colloquially known as C'ville, is an independent city in the Commonwealth of Virginia. It is the county seat of Albemarle County, which surrounds the city, though the two are separate legal entities. It is named after Queen Ch ...

, Floyd received a BA in Sociology from the

University of California - Berkeley A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, t ...

in 1971. She received an MS in Computer Science in 1987 and a PhD in 1989, both from UC - Berkeley. Her PhD was completed under the supervision of

Richard M. Karp Richard Manning Karp (born January 3, 1935) is an American computer scientist and computational theorist at the University of California, Berkeley. He is most notable for his research in the theory of algorithms, for which he received a Turing ...

. Floyd is best known in the field of

as the inventor of

Random Early Detection Random early detection (RED), also known as random early discard or random early drop is a queuing discipline for a network scheduler suited for congestion avoidance. In the conventional tail drop algorithm, a router or other network component b ...

("RED") active queue management scheme, thus founding the field of Active Queue Management (AQM) with

Van Jacobson Van Jacobson (born 1950) is an American computer scientist, renowned for his work on TCP/IP network performance and scaling.

. Almost all

Internet router A router is a networking device that forwards data packets between computer networks. Routers perform the traffic directing functions between networks and on the global Internet. Data sent through a network, such as a web page or email, is ...

s use RED or something developed from it to manage network congestion. Floyd devised the now-common method of adding

delay jitter In computer networking, packet delay variation (PDV) is the difference in End-to-end principle, end-to-end one-way delay between selected packets in a Flow (computer networking), flow with any Packet loss, lost packets being ignored.RFC 3393 The ...

to message timers to avoid synchronization.IEEE
"Sally Floyd"
IEEE Global History Network (last visited Oct. 7, 2012). Floyd, with

Vern Paxson Vern Edward Paxson is a Professor of Computer Science at the University of California, Berkeley. He also leads the Networking and Security Group at the International Computer Science Institute in Berkeley, California. His interests range from tr ...

, in 1997 identified the lack of knowledge of

network topology Network topology is the arrangement of the elements ( links, nodes, etc.) of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and contro ...

as the major obstacle in understanding how the Internet works. This paper, "Why We Don't Know How to Simulate the Internet", was re-published as "Difficulties in Simulating the Internet" in 2001 and won the

IEEE Communications Society The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...

's William R. Bennett Prize Paper Award. Floyd is also a co-author on the standard for TCP

Selective acknowledgement The Transmission Control Protocol (TCP) is one of the main protocols of the Internet protocol suite. It originated in the initial network implementation in which it complemented the Internet Protocol (IP). Therefore, the entire suite is commonly ...

(SACK),

Explicit Congestion Notification Explicit Congestion Notification (ECN) is an extension to the Internet Protocol and to the Transmission Control Protocol and is defined in RFC 3168 (2001). ECN allows end-to-end notification of network congestion without dropping packets. ECN is ...

(ECN), the

Datagram Congestion Control Protocol In computer networking, the Datagram Congestion Control Protocol (DCCP) is a message-oriented transport layer protocol. DCCP implements reliable connection setup, teardown, Explicit Congestion Notification (ECN), congestion control, and feature ne ...

(DCCP) and

TCP Friendly Rate Control TCP-Friendly Rate Control (TFRC) is a congestion control mechanism designed for unicast flows operating in an Internet environment and competing with TCP traffic. The goal is to compete fairly with TCP traffic on medium timescales, but to be much ...

(TFRC). She received the

IEEE Internet Award IEEE Internet Award is a Technical Field Award established by the IEEE in June 1999. The award is sponsored by Nokia Corporation. It may be presented annually to an individual or up to three recipients, for exceptional contributions to the adv ...

in 2005 and the ACM

SIGCOMM Award The SIGCOMM Award recognizes lifetime contribution to the field of communication networks. The award is presented in the annual SIGCOMM Technical Conference. The awardees have been: * 2022 Henning Schulzrinne * 2021 Hari Balakrishnan * 2020 Amin ...

in 2007 for her contributions to congestion control. She has been involved in the

Internet Architecture Board The Internet Architecture Board (IAB) is "a committee of the Internet Engineering Task Force (IETF) and an advisory body of the Internet Society (ISOC). Its responsibilities include architectural oversight of IETF activities, Internet Standards ...

, and was in 2007 one of the top-ten most cited researchers in computer science.

Awards

* 2007 - SIGCOMM Award from the ACM Special Interest Group on Data Communications. Recognized as most prestigious award to a scientist in computer networking. *

's William R. Bennett Prize Paper Award for "Difficulties in Simulating the Internet", by Floyd and Vern Paxson

Personal life and death

Floyd's father

Edwin The name Edwin means "rich friend". It comes from the Old English elements "ead" (rich, blessed) and "ƿine" (friend). The original Anglo-Saxon form is Eadƿine, which is also found for Anglo-Saxon figures. People * Edwin of Northumbria (die ...

was a mathematician at the

University of Virginia The University of Virginia (UVA) is a Public university#United States, public research university in Charlottesville, Virginia. Founded in 1819 by Thomas Jefferson, the university is ranked among the top academic institutions in the United S ...

. Floyd was married to Carole Leita. Floyd died at the age of 69 on August 25, 2019 in Berkeley, California from gallbladder cancer that had metastasized.

Selected notable papers

* S. Floyd and V. Jacobson, "Random Early Detection Gateways for Congestion Avoidance", ''

IEEE/ACM Transactions on Networking ''IEEE/ACM Transactions on Networking'' is a bimonthly peer-reviewed scientific journal covering communication networks. It is published by the IEEE Communications Society, the IEEE Computer Society, and the ACM Special Interest Group on Data C ...

'' (1993) * S. Floyd and K. Fall, "Promoting the Use of End-to-End Congestion Control in the Internet", ''

'' (1993) * V. Paxson and S. Floyd, "Wide Area Traffic: The Failure of Poisson Modeling", ''

'' (1995) * M. Mathis, J. Mahdavi and S Floyd, A Romanow, "TCP Selective Acknowledgement Options", RFC 2018 (1996) * S. Floyd and V. Paxson, "Why We Don't Know How to Simulate the Internet", Dec. 1997, Proceedings of the 1997 Winter Simulation Conference. Re-written as "Difficulties in Simulating the Internet", ''

'', vol. 9, no. 4 (August 2001). Winner of the

William R. Bennett Prize Paper Award, 2001.

References

External links

Sally Floyd's biography at ICSI
retrieved 8th Jan 2011 {{DEFAULTSORT:Floyd, Sally American computer scientists Fellows of the Association for Computing Machinery Internet pioneers University of California, Berkeley alumni University of California, Berkeley staff American women computer scientists Women Internet pioneers 1950 births 2019 deaths Deaths from gallbladder cancer Deaths from cancer in California People from Charlottesville, Virginia 21st-century American women