A smooth adaptive RED gateway for congestion control with TCP-friendly multimedia applications

For TCP-friendly multimedia applications, congestion control may bring about disadvantages such as the variability of sending rate and Round Trip Time although it helps to improve robustness of Internet. Aiming at alleviating this variability and further guaranteeing the user-perceived service quality in the aspect of network layer, this paper proposes a smooth adaptive adjustment mechanism for Random Early Detection (RED) gateway. By decomposing the adjustment of packet dropping probability into two orthogonal sections, each section is triggered differentially according to different sensitivity to influence on multimedia traffic. And thus the adaptivity and smoothness can be ensured in providing steady packet dropping probability and queuing time. Numerical results show that, our work can not only fit RED to different network loads, but also keep the queue size and packet dropping probability waving steadily even faced with short-lived bursty traffic.