On TCP reaction to Explicit Congestion Notification

Article type: Research Article

Authors: Kwon, Minseok | Fahmy, Sonia

Affiliations: Department of Computer Sciences, Purdue University, 250 N. University St., West Lafayette, IN 47907‐2066, USA Tel.: +1 765 494‐6183; Fax: +1 765 494‐0739; E‐mail: {kwonm,fahmy}@cs.purdue.edu

Abstract: We investigate the behavior of a new response strategy to TCP Explicit Congestion Notification (ECN). The new strategy is more aggressive in the short term, but preserves TCP long term behavior – without modifying the router ECN marking rate. A more aggressive short term behavior gives incentives for hosts to become ECN‐compliant. ECN serves as an early warning sign in this case. Our analysis demonstrates the effectiveness of the new TCP ECN behavior. Simulation results with short/long lived FTP, UDP and HTTP connections, multiple bottleneck configurations, and various TCP flavors and parameters, demonstrate higher throughput and reduced oscillations with the new response strategy.

Keywords: TCP congestion control, explicit congestion notification (ECN), random early detection (RED), active queue management, additive increase multiplicative decrease (AIMD)

Journal: Journal of High Speed Networks, vol. 13, no. 2, pp. 123-138, 2004