| Traffic management aims at efficiently allocating network resources and meeting the negotiated quality of service guarantees. Asynchronous transfer mode (ATM) networks allow seamless transport of voice, video and data on the same network. ATM networks provide several service categories for real-time and bulk data transfer. The available bit rate (ABR) service category attempts to provide (possibly non-zero) minimum rate guarantees, achieve fairness, and minimize cell loss by periodically indicating to sources the rate at which to transmit. Thus ABR is ideal for data distribution applications, and can perform well for real-time applications with the appropriate implementation and parameter choices.; Many ATM applications require multipoint communication, where one or more senders concurrently transmit to multiple receivers. Examples of such applications include audio and video conferencing, distance learning, server and database synchronization, and data distribution applications. A flexible and efficient ATM multipoint capability is thus required. This research focuses on the development of a traffic management framework for unicast and multicast connections in ATM networks, with a focus on the ABR service.; We examine point-to-multipoint and multipoint-to-point connection support, forming a foundation for multipoint-to-multipoint connections. Simplicity and scalability of the schemes are our main concerns. We develop definitions of the optimal and fair bandwidth allocations, based on connections, sources or flows. The operation of branch points that consolidate feedback, and that of merge points that regulate feedback, is designed. The performance of the schemes is analyzed under a large variety of realistic configurations and traffic patterns. Results indicate that the branch point consolidation algorithm exhibits stability and a fast transient response, while the merge point algorithm allocates fair rates and regulates feedback.; In addition, we examine ABR parameters and rate allocation schemes. Formulae are developed for selecting ABR parameter values, and the effect of round trip time and link bandwidths is determined. A novel mechanism for allocating rates, and a method for multiplexing virtual connections on virtual paths, are designed and analyzed. Most of the problems we resolve are not specific to ATM networks, and provide insight into traffic management design in computer networks in general. |
