Stability and Dynamics of TCP-NCR(DCR) Protocol

TytułStability and Dynamics of TCP-NCR(DCR) Protocol
Publication TypeConference Paper
Rok publikacji2007
AutorzyCzachórski T, Grochla K, Pekergin F
EditorGarcia-Vidal J., Cerda-Alabern l.
Conference NameLecture Notes in Computer Systems 4396 - Wireless Systems and Mobility in Next Generation Internet
Date Published5
PublisherSpringeVerlag
AbstractThe fluid-flow approximation models investigate with much success the dynamics and stability of TCP/RED connections. Their main assumption is that the fluctuations of variables characterizing the behaviour of the connections are relatively small, that enables the linearization of model and the use of traditional control analysis tools to obtain such measures as Bode gain, phase margins, tracking error or delay margin. In this article, preserving linear fluid-flow model, we propose its extension to the case when a network is composed of wired and wireless part. We consider a variant of TCP algorithm (TCP-DCR or its new version TCP-NCR) and fluid-flow differential equations representing the size of congestion window, mean queue at the bottleneck router and loss probability at a RED queue are supplemented with terms representing constant loss probability due to transmission in wireless part and probability that a fraction of these errors is recovered by a link level mechanism. The decrease of congestion window due to TCP mechanism is delayed to allow the link protocol to deal with the errors. The model considers the presence of uncontrollable UDP flows.