A congestion control method for real-time applications in ATM networks

Consider real-time applications running on an ATM network, we require the ATM network to provide a transmission guarantee for real-time service. However, when congestion occur in the ATM network, the delays encountered by cells begin to increase rapidly, buffers overflow and drop cells beyond a specified limit, and the throughput begins to drop, even approaching zero or deadlock. We first review some congestion control methods, then we present results of a study of congestion control for real-time communication based on ATM networks. In ATM networks, congestion usually results in cell loss. Based on the time limit and priority, the cells that compete for the same output line could be lined according to the character of real-time service. We adopt a priority control algorithm for providing different QoS bearer services that can be implemented by using threshold methods at the ATM switching nodes, the cells of different deadline and priority could be dealt with according to the necessity. Experiments show the proposed algorithm is effective in the congestion control of ATM real-time networks.