• List of Articles TCP

      • Open Access Article

        1 - Sliding Mode Controller for TCP Congestion Control
        roohollah barzamini masoud shafiee
        In this paper a new sliding mode controller for congestion problem in TCP networks has been proposed. Congestion occurs due to high network loads. It affects some aspects of network behavior. Congestion control prevents or reduces loads in bottlenecks and manages traffi More
        In this paper a new sliding mode controller for congestion problem in TCP networks has been proposed. Congestion occurs due to high network loads. It affects some aspects of network behavior. Congestion control prevents or reduces loads in bottlenecks and manages traffic. By using control theory, closed loop data transfer processing structure in computer networks can cope with the congestion problem. Sliding mode controller can provide robust behavior in presence of uncertainties and disturbances. In sliding mode control, states should be reached to a predefined surface (sliding surface), in a limited time and remain on the same surface over time. Moving on the sliding surface is independent of the uncertainties, so this technique is an approach of robust control. After applying controller to the system, stability of the system with controller has been studied by Lyapunov stability approach. Simulation results show the efficiency of the sliding mode controller in different scenarios. Manuscript profile
      • Open Access Article

        2 - Sliding mode control for congestion in TCP/IP networks
        roohollah barzamini masoud shafiee
        Congestion phenomenon is one of the important problems faced by computer network designers and in recent years it has reduced the efficiency of networks. So far, various methods have been proposed to prevent and control this phenomenon, which are based on control theory More
        Congestion phenomenon is one of the important problems faced by computer network designers and in recent years it has reduced the efficiency of networks. So far, various methods have been proposed to prevent and control this phenomenon, which are based on control theory. For this purpose, the closed loop structure of the data transfer process in computer networks can be considered in such a way that the controllers from the Dynamic Queue Management (AQM) family are designed to be implemented in the pathfinders of the network and the rest of the network from the point of view of the pathfinder. It is defined as the control target system or plant. In the field of AQM controller design, many researches have been done and many controllers have been designed. In this article, sliding mode control is introduced as AQM controller. Sliding mode control is resistant to modeling uncertainties and disturbances. In sliding mode control, mode paths must reach a predefined level (sliding level) in a limited period of time and remain at the same level over time. Movement on the sliding surface is independent of uncertainties; Therefore, this technique is one of the resistant control methods. After implementing the sliding mode control on the network model, with the help of Matlab software, how the network behaves in the presence of this The controller was examined and the results obtained were compared with the results of several other controllers. Manuscript profile
      • Open Access Article

        3 - Defense against SYN Flooding Attacks: A Scheduling Approach
        Shahram Jamali Gholam Shaker
        The TCP connection management protocol sets a position for a classic Denial of Service (DoS) attack, called the SYN flooding attack. In this attack attacker sends a large number of TCP SYN segments, without completing the third handshaking step to quickly exhaust connec More
        The TCP connection management protocol sets a position for a classic Denial of Service (DoS) attack, called the SYN flooding attack. In this attack attacker sends a large number of TCP SYN segments, without completing the third handshaking step to quickly exhaust connection resources of the victim server. Therefore it keeps TCP from handling legitimate requests. This paper proposes that SYN flooding attack can be viewed metaphorically as result of an unfair scheduling that gives more opportunity to attack requests but prevents legal connections from getting services. In this paper, we present a scheduling algorithm that ejects the half connection with the longest duration, when number of half open connections reaches to the upper bound. The simulation results show that the proposed defense mechanism improves performance of the under attack system in terms of loss probability of requests and share of regular connections from system resources. Manuscript profile