Hybrid Modeling of TCP Congestion Control

  • João P. Hespanha
  • Stephan Bohacek
  • Katia Obraczka
  • Junsoo Lee
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2034)


In this paper we propose a hybrid model for TCP’s congestion control mechanism operating under drop-tail queuing policy. Using this model we confirmed the standard formula \( T: = \tfrac{{1.23}} {{\overline {RTT} \sqrt p }} \) used by TCP-friendly congestion control algorithms, which relates the average packet drop rate p, the average round-trip time \( \overline {RTT} \) , and the average throughput T. The hybrid model also allows us to understand the transient behavior and theoretically predict the flow synchronization phenomena that have been observed in simulations and in real networks but, to the best of our knowledge, have not been theoretically justified. This model can also be used to detect abnormalities in TCP traffic flows, which has important applications in network security.


Window Size Congestion Control Average Throughput Queue Size Drop Rate 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • João P. Hespanha
    • 1
  • Stephan Bohacek
    • 1
  • Katia Obraczka
    • 2
  • Junsoo Lee
    • 1
  1. 1.University of Southern CaliforniaLos AngelesUSA
  2. 2.University of CaliforniaSanta CruzUSA

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