Congestion control strategies for mixed X.25/frame relay networks

The paper addresses traffic management strategies in multi-service corporate communication networks. In particular, it proposes a unified congestion control scheme for mixed X.25/frame relay networks which meets users´ requirements of effectiveness, fairness, and implementation efficiency. Key elements of the design include early detection of impending congestion by the various network resources, explicit notification of congestion information to the affected network services, and the use of adaptive rate and window control mechanisms by the various services to limit traffic admission into the network during overload. A comprehensive simulation test-bed was constructed for evaluating and tuning the proposed algorithms, and the results were verified against live networking equipment. Simulation results confirm the success of the congestion control strategy in maximizing network throughput, and minimizing users´ packet loss rate and end-to-end delay under a wide range of congestion situations. The described algorithms have been successfully incorporated in the design of large multi-service data communication networks