Window-based Flow Control Mechanism Research Articles

Comparative performance analysis of TCP-based congestion control algorithms

Congestion control is a challenging problem for us. We tried to analyse the end-to-end congestion control algorithms, i.e., TCP Tahoe, TCP Reno, TCP Newreno, TCP Veno, etc. In the literature, TCP implements a window-based flow control mechanism which leads to vary the window size within a range. Older TCP designed assuming packet loss is always inferred due to congestion on link which leads to degradation of performance in wireless networks where random loss occurred due to transmission error or noise. This well-known problem affects on TCP performance. TCP Veno has been successfully proposed to deal with random loss efficiently and its performance is discussed in the literature. This paper evaluates the complex model for different performance parameters, i.e., throughput, queuing delay, goodput, etc. In addition, we have also proposed new performance metric to measure the network performance. We also tried to study and compare the analytical results with simulated data at different levels of loss rate.

Fair resource allocation and stability for communication networks with multipath routing

Multipath networks allow that each source-destination pair can have several different paths for data transmission, thus they improve the performance of increasingly bandwidth-hungry applications and well cater for traffic load balancing and bandwidth usage efficiency. This paper investigates fair resource allocation for users in multipath networks and formulates it as a multipath network utility maximisation problem with several fairness concepts. By applying the Lagrangian method, sub-problems for users and paths are derived from the resource allocation model and interpreted from an economic point of view. In order to solve the model, a novel rate-based flow control algorithm is proposed for achieving optimal resource allocation, which depends only on local information. In the presence of round-trip delays, sufficient conditions are obtained for local stability of the delayed algorithm. As for the end-to-end implementation in Internet, a window-based flow control mechanism is presented since it is more convenient to implement than rate-based flow control.

TCP friendly protocols for media streams over heterogeneous wired–wireless networks

The growing need for Internet friendly streaming protocols prompted us to develop IFTP (Internet Friendly Transport Protocol). IFTP is a protocol with an inherent rate-based flow control mechanism designed to emulate TCP’s window-based flow control mechanism. In this paper, we present two proposals to improve the performance of IFTP in networks with wireless links. The first is IFTP-W, which specifies an error-sensitive section. Bit errors not occurring in this section are ignored. The second is IFTPV, which distinguishes between losses due to congestion and those due to the wireless link. In this paper, we present the performance of IFTP-W with varying error-sensitive section lengths on networks with varying link qualities. We also analyze the performance of IFTPV in extensive scenarios with various network conditions. The results show that both proposals maintain the TCP-friendliness and fairness properties, but perform better than IFTP on wireless networks.