Higher Order Delay Functions for Delay-Loss Based TCP Congestion Control

T Edwan, L Guan, G Oikonomou, I Phillips

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)

4 Citations (Scopus)


TCP-Illinois aims to address TCP's low throughput when operating in high-speed, high-delay networks. Previous research has shown that, due to its linear increase behaviour and to its relatively long congestion epochs, TCP-Illinois exhibits sub-optimal scaling behaviour with an increasing path Bandwidth-Delay Product (BDP). This paper discloses our contributions towards improving the aggressiveness and responsiveness of loss-based TCP congestion control algorithms. We formally show that higher order versions (of power n) of the delay functions used by TCP-Illinois become more aggressive and responsive with an increasing value of n. Based on this finding, we propose three variants: i) a second order (quadratic) version of additive increase and multiplicative decrease (TCP-Q), ii) a second order multiplicative decrease only (TCP-Fq) and iii) a sub-linear multiplicative decrease only (TCP-Fs). By modifying the TCP-Illinois code in the GNU/Linux kernel, we obtained the three corresponding modules and used them for our simulations using the TCP/Linux patch for ns2. Based on standardised congestion control metrics, we conducted a comparative analysis between our variants and a number of relevant high speed TCP algorithms. Simulation results agree with our analytical findings; compared to TCP-Illinois, TCP-Q exhibits shorter congestion epochs and thus better responsiveness and convergence.
Translated title of the contributionHigher Order Delay Functions for Delay-Loss Based TCP Congestion Control
Original languageEnglish
Title of host publicationProc. 6th Wireless Advanced
Pages1 - 6
Publication statusPublished - Jun 2010

Bibliographical note

Name and Venue of Event: London, UK


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