Comparative performance analysis of fuzzy verses conventional congestion control for ABR service in ATM networks

The transfer of real time multimedia traffic has become the important issue in recent years. Broadband Integrated Services Digital Networks (B-ISDNs) provide for the integration of Multimedia services for transmitting on a transport medium using Asynchronous Transport Mode (ATM) technique. ATM has been recommended for the implementation of B-ISDNs based on its flexibility and versatility in handling Multimedia traffic. ATM networks have multiple service classes which allow audio, video and data to share the same network. The Available Bit Rate (ABR) service class is designed to efficiently support data traffic.; Traffic management involves the design of a set of mechanisms which insure that the network bandwidth, buffer and computational resources are efficiently utilized while meeting the various Quality of Service (QoS) guarantees given to sources as part of a traffic contract. In this dissertation we address the problem of designing traffic management mechanisms for one class—the ABR service class in ATM networks.; We consider few aspects of this problem in this dissertation. First, the ABR service requires a mechanism to carry rate feedback from the network switches to the sources. We design a novel fuzzy control switch algorithm which calculates the rate allocations to satisfy different sets of goals. Second, we design a set of source end-system mechanisms which respond to network feedback, and perform control in the case when feedback is disrupted or is stale. Third, we validate the performance of the service for various ABR demand patterns. Persistent and bursty traffic is considered and the transient and steady state performance is analyzed. The algorithm is tested for link utilizations, cell loss, fairness in allocation and the buffer occupancy oscillations. Fourth, we consider the performance analysis and design issues for the case of multiple bottlenecks in the network, and compare the overall performance of our approach to other conventional and fuzzy congestion control schemes.; In summary, this dissertation work presents a novel approach to flow control issues in ATM ABR service class, and the approach developed is applicable to a wider class of high-speed packet networks.