PPT-Never Been KIST: Tor’s Congestion Management Blossoms with Kernel-Informed Socket Transport

23 rd USENIX Security Symposium August 20 th 2014 Rob Jansen US Naval Research Laboratory John Geddes University of Minnesota Chris Wacek Georgetown University Micah Sherr Georgetown University. Transport Layer. 3-. 2. Principles of Congestion Control. Congestion:. informally: “too many sources sending too much data too fast for . network. to handle”. different from flow control!. manifestations:. 3-. 1. Chapter 3. Transport Layer. Computer Networking: A Top Down Approach . 6. th. edition . Jim Kurose, Keith Ross. Addison-Wesley. March 2012. Part 4: Congestion control. Transport Layer. 3-. 2. MSc Urban & Regional Planning. 28 January 2013. Road pricing in England: has its time finally come?. Agenda. Historical context. The problem as was. The problem looking forward. Experience from London. DC-area Anonymity, Privacy, and Security Seminar. January 24. th. , . 2014. Rob . Jansen. U.S. Naval Research . Laboratory. *Joint with . John . Geddes, Chris . Wacek. , Micah . Sherr. , Paul . Syverson. CS 381. 3/7/2017. Transport. . Layer. 3-. 2. Chapter 3 outline. 3.1 transport-layer services. 3.2 multiplexing and . demultiplexing. 3.3 connectionless transport: UDP. 3.4 principles of reliable data transfer. 14. Transport Layer . (Transmission Control Protocol). slides are modified from . J. Kurose & K. Ross. University of Nevada – Reno. Computer Science & Engineering Department. Fall . 2011. CPE 400 / 600. udp. Congestion control. Congestion occurs when machines send too many packets to a network too quickly from the transport layer. . Performance will become degraded as packets are dropped and lost.. Congestion Control. If the transport entities on many machines send too many packets into the network too quickly, the network will become congested, with performance degraded as the packets are delayed and lost.. Multiplexing and demultiplexing. Connectionless transport: UDP. Principles of reliable data transfer . Connection-oriented transport: TCP. Principles of congestion control. TCP congestion control . Evolution of transport-layer functionality. , the scheme is estimated to save £2.5 million per year as a result ofa reduction in vehicle kilometres travelled, fuel consumption and Transport for London website, “Congestion Charging” (2007 3 authority with sufficient resources and power to move the urban transport agenda at the required fast pace to meet Cairo’s increasing congestion challenges. 2 5 . World experience in tackling t The International Transport Forum is an intergovernmental organisation with 59 member countries. It acts as a think tank for transport policy and organises the Annual Summit of transport ministers. Transport Layer. Computer Networking: A Top Down Approach . 4. th. edition. . Jim Kurose, Keith Ross. Addison-Wesley, July 2007. . Computer Networking: A Top Down Approach. , . 5. th. edition. . Jim Kurose, Keith Ross. 3.1 transport-layer services. 3.2 multiplexing and demultiplexing. 3.3 connectionless transport: UDP. 3.4 principles of reliable data transfer. 3.5 connection-oriented transport: TCP. segment structure.