Research And Implementation On Admission Control Of Access Convergence Router

Large-scale Access Convergence Router adopts the bandwidth design solution that a certain amount of bandwidth is distributed to each user, thus the users are assured the normal configuration service. In practice, however, distributing bandwidth solely according to users' normal configuration will cause excessive waste of bandwidth resources. Therefore, with the support of National 863 Plan Essential Project "Research on system performance and key technologies of large-scale Access Convergence Router (ACR)" and starting from the current admission control techniques, the author stated a novel two levels ACR strategy of bandwidth threshold and queue threshold based on high speed and large capacity buffer. The ACR EMD admission control module solution was designed and then realized by hardware circuits.The contributions present in this paper include:The current admission control algorithms are comprehensive described and compared. Based on that, the demands for ACR admission control are thoroughly analyzed, which provides the theory and design methods for ACR admission control algorithm.A novel two levels ACR strategy based on users' bandwidth need and queue threshold is proposed. The first level strategy is an adaptive admission control algorithm BASAC based on bandwidth control, and adopts different admission methods according to the bandwidth resource conditions. While the second level strategy is a dynamic queue threshold admission control algorithm DQTAC, which dynamically adjusts queue threshold, and thus can effectively assure the bandwidth for high priority services.A multi-level buffer architecture MLBA based on parallel packet switch is designed, which distributes the packets entering the main buffer to each sub-buffer for processing. As a result, the total of small and slow sub-buffers is proved out equivalent to a high capacity and high speed buffer, in order to smooth the burst traffic effectively.An ACR EMD 1000M admission control module is designed, realized, and tested. The results indicate that this module is able to satisfy the functions and performance requirement of ACR EMD and effectively raised the efficiency of bandwidth distribution.