H-TCP – Congestion Control for High Delay-Bandwidth Product Networks

• Analysis and design of congestion control in synchronised communication networks
  R.N.Shorten, D.J.Leith, J.Foy, R.Kilduff
  Proc. 12th Yale Workshop on Adaptive & Learning Systems, May 2003.
• A Positive Systems Model of TCP-like Congestion Control: Asymptotic Results
  HI Technical Report, April 2004.
  R.N.Shorten, F.Wirth, D.J.Leith
• H-TCP: TCP for high-speed and long-distance networks.
  R.N.Shorten, D.J.Leith
  Proc. PFLDnet, Argonne, 2004.
• Modelling TCP Congestion Control Dynamics in Drop-Tail Environments.
  R.N.Shorten, D.J.Leith, F.Wirth
  Automatica 2005, Vol 41, pp725-730.
• Experimental Evaluation of TCP Protocols for High-Speed Networks
  Y.Li, D.J.Leith, R.N.Shorten
  HI Technical Report, June 2005.
• H-TCP: A framework for congestion control in high-speed and long-distance networks.
  D.J.Leith, R.N.Shorten, Y.Li
  HI Technical Report, August 2005.
• On RTT Scaling in H-TCP.
  D.J.Leith, R.N.Shorten
  Discussion Note.
• Experimental evaluation of high-speed congestion control protocols
  Yee, T., D. Leith, R. Shorten
  Transactions on Networking, 2007, Vol 15, issue 5, pp1109-1122.
• Evaluating the Performance of TCP Stacks for High-Speed Networks..
  Li, Y.T., Leith,D.J., Even,B.
  Proc. Protocols for Fast Long Distance Networks 2006, Nara, Japan
• On AIMD congestion control, queue provisioning, and network efficiency
  Shorten, R., D. Leith
  Transactions on Networking, 2007, Vol 15, Issue 4, pp866-877.
• Experimental Evaluation of Cubic TCP
  Leith,D.J., Shorten, R.N.,McCullagh,G.
  Extended version of paper presented at Proc. Protocols for Fast Long Distance Networks 2007, Los Angeles
• Next Generation TCP: Open Questions.
  Douglas Leith, Robert Shorten.
  Proc. PFLDnet 2008
• Impact of Convergence Rate on TCP Flow Completion Times

• Original linux patches implementing HTCP and improving slow path efficiency in network stack:
  2.4.23, 2.6.6
  Note: H-TCP maintained as part of standard Linux kernel distribution from 2.6.13 onwards.
• H-TCP is available in the Linux kernel as of 2.6.13, but an error was introduced that was not fixed until 2.6.16. If you are conducting tests of H-TCP, please use Linux kernel version 2.6.16 and above or contact us for the appropriate patch to the previous versions.
• H-TCP is now available in FreeBSD. Implemented at Swinburne with funding from Cisco. See here.
• ns implementation of HTCP

• Early tests were carried out at SLAC in October 2003 comparing HTCP, FAST, Highspeed TCP, Scalable and some other proposals. Unfortunately different network stack implementations were used for each congestion control algorithm, with numerous specific changes in most stacks (not HTCP at that time) to improve SACK processing efficiency (which has known problems, see our report, also Tom Dunigan’s page) and other substantive changes. Comparisons of protocol performance is therefore not possible in these tests.
• The group at Caltech briefly report on HTCP tests in their GridNets 2004 paper.
• Injong Rhee at North Carolina have carried out DummyNet tests here.
• Results of 2007 evaluation tests at UCL and HI are available here.
• Results of extensive tests at NIST in 2009 are here
• Results of 2009 evaluation tests over home DSL links at Swinburne to appear at Networking 2009.

• Hamilton Institute Networking Group