Transmission Control Protocol Model Research Articles

Uniform stability of nonlinear systems with state-dependent delay

In this paper, we study the uniform stability (US) of nonlinear systems with state-dependent delay (SDD), where the SDD is not assumed to be a priori bounded since it is dependent on the state of the system. We use some Lyapunov functions coupled with differential inequality techniques tailed at SDD to obtain sufficient conditions for US of nonlinear systems. Two numerical examples and their simulations are given, where one of them is from the fluid-flow model of Transmission Control Protocol (TCP) behavior in active queue management (AQM) involving state-dependent queuing delay, to demonstrate the effectiveness and novelty of our proposed results.

Partial Diffusion Markov Model of Heterogeneous TCP Link: Optimization with Incomplete Information

The paper presents a new mathematical model of TCP (Transmission Control Protocol) link functioning in a heterogeneous (wired/wireless) channel. It represents a controllable, partially observable stochastic dynamic system. The system state describes the status of the modeled TCP link and expresses it via an unobservable controllable MJP (Markov jump process) with finite-state space. Observations are formed by low-frequency counting processes of packet losses and timeouts and a high-frequency compound Poisson process of packet acknowledgments. The information transmission through the TCP-equipped channel is considered a stochastic control problem with incomplete information. The main idea to solve it is to impose the separation principle on the problem. The paper proposes a mathematical framework and algorithmic support to implement the solution. It includes a solution to the stochastic control problem with complete information, a diffusion approximation of the high-frequency observations, a solution to the MJP state filtering problem given the observations with multiplicative noises, and a numerical scheme of the filtering algorithm. The paper also contains the results of a comparative study of the proposed state-based congestion control algorithm with the contemporary TCP versions: Illinois, CUBIC, Compound, and BBR (Bottleneck Bandwidth and RTT).

Improved global stability condition analysis for time-delay fast active queue management scalable transmission control protocol

The nonlinear time-delay fast active queue management scalable transmission control protocol model was studied in this article. By analyzing the boundedness properties for solution trajectory of the fast active queue management scalable transmission control protocol model, the iterative relations of fast active queue management scalable transmission control protocol trajectory bounds were obtained. Furthermore, we calculated the maximum growth direction of the delay term in the integral interval and applied the backward method to calculate the lower conservative bound corresponding to each time of the delay term. Therefore, the global stability parameter condition of fast active queue management scalable transmission control protocol, which was less conservative than the existing global stability conditions, was obtained in this article. The validity of the stability conditions obtained in this article was verified by NS-2 simulation experiment.

Novel Active Queue Management Scheme for Routers in Wireless Networks

Congestion stability and prevention is the main aim of any decent network traffic management scheme. The protocol that drives congestion control in IP networks, called The Transmission Control Protocol (TCP), is plagued by bandwidth underutilization when implemented on wireless networks. The management of network trunk queue size is the goal of this paper, along with its antecedent delay issues with Active Queue Management (AQM) algorithms that overcomes the bandwidth underutilization issue faced by TCP flows in wireless networks. Two adaptive TCP models, specifically built for wireless networks, were created. This made it possible to implement feedback control techniques in the chosen AQM design for queue management. The two AQM policies were created with the help of Model Predictive Control (MPC) and Self-Tuning Control (STC). A very thorough comparison was made between the developed AQM schemes and two Early Detection Controllers, namely, Random Early Detection (RED) and Fixed-Parameter Proportional Integral (PI). Under varying wireless network conditions, the results obtained from simulating the proposed queue management scheme in MATLAB® confirmed that the fixed PI and RED controllers were, by comparison, inferior in performance. Copyright © 2018 Praise Worthy Prize S.r.l. - All rights reserved.

Robust Stability and Stabilization Of TCP‐Networked Control Systems with Multiple Delay System Modeling

AbstractThis paper presents a new model for networked control systems (NCSs) under transmission control protocol (TCP) as a multiple‐delay system by considering both sensor to controller and controller to actuator delays. An analytical TCP model has been considered for the network part, and an active queue management (AQM) controller is designed to regulate the desired queue length, which ensures holding the network induced delay and its variation within their lower bounds. The model is assumed to possess structured uncertainties due to the stochastic nature of the network. Robust stability and stabilization conditions are derived in terms of linear matrix inequalities (LMIs) by applying the Lyapunov‐Krasovskii stability criterion. Illustrative examples are presented and it has been shown that the proposed method will obtain less conservative results compared to the existing approaches in the literature.

Guaranteed Cost Control of Networked Control Systems Under Transmission Control Protocol with Active Queue Management

AbstractThe problem of a guaranteed cost controller design of networked control systems under transmission control protocol (TCP) is derived. To improve the overall performance of the networked control system, a scheme to simultaneously control the plant and the network is presented. An analytical TCP model is used to design active queue management (AQM) to achieve the desired queue length, which is helpful in reducing the variation of the network induced delay. Moreover, a new closed loop model of networked control systems is obtained by augmenting the TCP communication model with the control plant. The guaranteed cost controller is addressed in terms of a linear matrix inequality (LMI) to render the system asymptotically stable based on Lyapunov‐Krasovskii theory and weighted technology. Finally, numerical simulations are included to demonstrate the theoretical results.

Critical Scale for a Continuous AIMD Model

A scaled version of the general AIMD model of transmission control protocol (TCP) used in Internet traffic congestion management leads to a Markov process x(t) representing the time dependent data flow that moves forward with constant speed on the positive axis and jumps backward to γx(t), 0 < γ < 1 according to a Poisson clock whose rate α(x) depends on the interval swept in between jumps. We give sharp conditions for Harris recurrence and analyze the convergence to equilibrium on multiple scales (polynomial, fractional exponential, exponential) identifying the critical case xα(x) ∼ β. Criticality has different behavior according to whether it occurs at the origin or infinity. In each case, we determine the transient (possibly explosive), null—and positive—recurrent regimes by comparing β to ( − ln γ)− 1.

Design of proportional-derivative-type state feedback controllers for congestion control of transmission control protocol networks

A new proportional-derivative-type state feedback controller is proposed for congestion control of transmission control protocol (TCP) networks. An analytical TCP model is adopted. In the proposed control scheme, it is possible to efficiently control the TCP traffic using only the queue length at the router without the need to know the TCP window size which is not available locally. The results are presented in terms of delay-dependent linear matrix inequality. The proposed method is verified by simulation examples using NS software, and the effectiveness and superiority of our method over other control schemes, such as the proportional-integral, random early detection and generalised minimum variancemethods, are also shown.

Analytical modeling of Transmission Control Protocol NewReno using Generalized Stochastic Petri Nets

SUMMARYThis paper presents a novel analytical model of Transmission Control Protocol (TCP) using a generalized stochastic Petri net (GSPN). Extensive simulation work has been done for the performance evaluation of TCP NewReno protocol. In view of the limitations of the simulation technique, we present an analytical approach using GSPN. A GSPN is a useful mathematical tool that solves continuous time Markov chains for complex systems and evaluates the stationary behavior. In this paper, we analyze the slow‐but‐steady variant of TCP NewReno. The model captures the behavioral aspects of the slow start and the congestion avoidance phase together with the fast retransmit and recovery capabilities of TCP NewReno. Performance metrics such as throughput, goodput, and task completion time of the system are obtained. The effect of variation in the model parameters on the performance is studied. The results are validated using the network simulator, and their accuracy is verified by evaluating the confidence interval. The performance of the proposed model is compared with that of TCP Reno. The performance of the proposed model is also compared with one of the previous models. The numerical illustrations and comparison of the proposed technique with simulation validates the accuracy, efficiency, and competence of the GSPN technique. While GSPN modeling for TCP is investigated in depth for the TCP NewReno and TCP Reno variant in this paper, other protocols could be also analyzed similarly. Copyright © 2013 John Wiley &amp; Sons, Ltd.

A rate-based TCP traffic model to accelerate network simulation

Traditional discrete-event simulation of large-scale networks at the packet level is computationally expensive. This article presents a fast rate-based transmission control protocol (RTCP) traffic model designed to reduce the time and space complexity for simulating network traffic whilst maintaining good accuracy. A distinct feature of the proposed model is that the transmission control protocol (TCP) congestion control behavior is represented using analytical models that describe the send rate at the traffic source as a function of the round-trip time and the packet loss rate at different phases of a TCP connection. Rather than modeling at the granularity of individual packets visiting the intermediate routers, the model approximates traffic flows as a series of rate windows, each consisting of a number of packets considered to possess the same arrival rate. The model calculates the queuing delays and the packet losses as these rate windows traverse the individual network queues along the flow path. The proposed RTCP model is able to achieve a performance advantage over other TCP models, by integrating analytical solutions and aggregating traffic using rate windows. Empirical results show that the RTCP model can correctly capture the overall TCP behavior and achieve a speedup of more than two orders of magnitude over the corresponding detailed packet-oriented simulation.

Feedback control for router management and TCP/IP network stability

Several works have established links between congestion control in communication networks and feedback control theory. In this paper, following this paradigm, the design of an AQM (active queue management) ensuring the stability of the congestion phenomenon at a router is proposed. To this end, a modified fluid flow model of TCP (transmission control protocol) that takes into account all delays of the topology is introduced. Then, appropriate tools from control theory are used to address the stability issue and to cope with the time-varying nature of the multiple delays. More precisely, the design of the AQM is formulated as a structured state feedback for multiple time delay systems through the quadratic separation framework. The objective of this mechanism is to ensure the regulation of the queue size of the congested router as well as flow rates to a prescribed level. Furthermore, the proposed methodology allows to set arbitrarily the QoS (quality of service) of the communications following through the controlled router. Finally, a numerical example and some simulations support the exposed theory.

Stability of TCP Dynamics in Large Data Networks

We study the stability of the dynamics of a deterministic model of Transmission Control Protocol (TCP) traffic in a multiple flow, multiple router data network. In this model, flow rates increase continuously until network congestion causes them to decrease discontinuously. In computer simulations of small networks, trajectories appear to approach periodic orbits for most but not all parameter values. We prove that if all the data flows are coupled, periodic orbits must be exponentially attracting and thus persist under parameter changes, regardless of network size. Furthermore, we describe the model as a discontinuous but piecewise affine map and show that trajectories must either approach a periodic orbit or come arbitrarily close to map discontinuities.

Design of Active Queue Management System for Scalable TCP in High Speed Networks

The Scalable Transmission Control Protocol (TCP), based on a multiplicative increase, multiplicative decrease congestion avoidance algorithm, has been proposed recently to overcome the inability of Standard TCP to utilize the full bandwidth in high speed networks. This paper employs a novel approach to derive a transfer-function model of Scalable TCP that is then employed in a control-theoretic design of random early detection (RED)-based active queue management (AQM) for such a network. Robust stability of the proposed scheme is established under prescribed conditions, and the design is validated by discrete-event simulations using the ns2 tool.

MULTI-RED CONTROLLER FOR ROUTER FAULT ACCOMMODATION

In this work a classical model-based controllers for Active Queue Management(AQM) routers supporting dynamic model of Transmission Control protocol (TCP) flows is developed. Using this model, an AQM control system using Random Early Detection (RED) controller is designed. In first part, the interc0onnection terms of TCP are simplified. Second part, the stability of the closed loop system is studied on the basis of a simplified Internet router model (Misra et al., 2000). In the proposed approach classical RED controller is adapted in order to take into account the network parameters variations. In the last part of the paper, the approach is validated using Matlab Simulation.

Modelling of wireless TCP for short-lived flows: Research Articles

The transmission control protocol (TCP) is one of the most important Internet protocols. It provides reliable transport services between two end-hosts. Since TCP performance affects overall network performance, many studies have been done to model TCP performance in the steady state. However, recent researches have shown that most TCP flows are short-lived. Therefore, it is more meaningful to model TCP performance in relation to the initial stage of short-lived flows. In addition, the next-generation Internet will be an unified all-IP network that includes both wireless and wired networks integrated together. In short, modelling short-lived TCP flows in wireless networks constitutes an important axis of research. In this paper, we propose simple wireless TCP models for short-lived flows that extend the existing analytical model proposed in [IEEE Commun. Lett. 2002; 6(2):85–88]. In terms of wireless TCP, we categorized wireless TCP schemes into three types: end-to-end scheme, split connection scheme, and local retransmission scheme, which is similar to the classification proposed in [IEEE/ACM Trans. Networking 1997; 756–769]. To validate the proposed models, we performed ns-2 simulations. The average differences between the session completion time calculated using the proposed model and the simulation result for three schemes are less than 9, 16, and 7 ms, respectively. Consequently, the proposed model provides a satisfactory means of modelling the TCP performance of short-lived wireless TCP flows. Copyright © 2005 John Wiley & Sons, Ltd.A preliminary version of this paper has appeared in the Proceedings of the IEEE Vehicular Technology Conference (VTC) 2003-Spring, Jeju, Korea, April 2003.

Modelling of wireless TCP for short-lived flows

The transmission control protocol (TCP) is one of the most important Internet protocols. It provides reliable transport services between two end-hosts. Since TCP performance affects overall network performance, many studies have been done to model TCP performance in the steady state. However, recent researches have shown that most TCP flows are short-lived. Therefore, it is more meaningful to model TCP performance in relation to the initial stage of short-lived flows. In addition, the next-generation Internet will be an unified all-IP network that includes both wireless and wired networks integrated together. In short, modelling short-lived TCP flows in wireless networks constitutes an important axis of research. In this paper, we propose simple wireless TCP models for short-lived flows that extend the existing analytical model proposed in [IEEE Commun. Lett. 2002; 6(2):85–88]. In terms of wireless TCP, we categorized wireless TCP schemes into three types: end-to-end scheme, split connection scheme, and local retransmission scheme, which is similar to the classification proposed in [IEEE/ACM Trans. Networking 1997; 756–769]. To validate the proposed models, we performed ns-2 simulations. The average differences between the session completion time calculated using the proposed model and the simulation result for three schemes are less than 9, 16, and 7 ms, respectively. Consequently, the proposed model provides a satisfactory means of modelling the TCP performance of short-lived wireless TCP flows. Copyright © 2005 John Wiley & Sons, Ltd.

Modeling TCP-vegas under on/off traffic

The success of the current Internet relies to a large extent on a cooperation between the users and the network. The network signals its current state to the users by marking or dropping packets. The users then strive to maximize the sending rate without causing network congestion. To achieve this, the users implement a flow-control algorithm that controls the rate at which data packets are sent into the Internet. More specifically, the Transmission Control Protocol (TCP) is used by the users to adjust the sending rate in response to changing network conditions. TCP uses the observation of packet loss events and estimates of the round trip time (RTT) to adjust its sending rate.In this thesis we investigate and propose stochastic models for TCP. The models are used to estimate network performance like throughput, link utilization, and packet loss rate. The first part of the thesis introduces the TCP protocol and contains an extensive TCP modeling survey that summarizes the most important TCP modeling work. Reviewed models are categorized as renewal theory models, fixed-point methods, fluid models, processor sharing models or control theoretic models. The merits of respective category is discussed and guidelines for which framework to use for future TCP modeling is given.The second part of the thesis contains six papers on TCP modeling. Within the renewal theory framework we propose single source TCP-Tahoe and TCP-NewReno models. We investigate the performance of these protocols in both a DropTail and a RED queuing environment. The aspects of TCP performance that are inherently depending on the actual implementation of the flow-control algorithm are singled out from what depends on the queuing environment.Using the fixed-point framework, we propose models that estimate packet loss rate and link utilization for a network with multiple TCP-Vegas, TCP-SACK and TCP-Reno on/off sources. The TCP-Vegas model is novel and is the first model capable of estimating the network's operating point for TCP-Vegas sources sending on/off traffic. All TCP and network models in the contributed research papers are validated via simulations with the network simulator ns-2.This thesis serves both as an introduction to TCP and as an extensive orientation about state of the art stochastic TCP models.