| This thesis is focused on the flow control of Available Bit Rate or ABR services in ATM (Asynchronous Transfer Mode) networks. The purpose of this work is to develop a stable and efficient flow control protocol that is suitable for high-speed, multi-hop wide area ATM networks.; The currently proposed ABR flow control schemes may suffer from instability, low-efficiency and difficulty to interoperate due to the feedback mechanisms or the bandwidth management algorithms they employ. This thesis systematically analyzes the possible options of the ABR flow control scheme depending on the selection of controller granularity and the combination of fundamental flow control elements. Alternate feasible flow control schemes are identified and guidelines are presented for the design and implementation of the flow control protocols.; An interval-based, hop-by-hop, explicit rate ABR flow control protocol (FlowNet) is developed based on a set of heuristic flow control rules and a theoretically-proven loss-free flow control scheme. FlowNet employs a periodical feedback mechanism that enables straightforward bandwidth allocation. It implements the co-management of switch buffer space and link bandwidth to maximize the overall network resource utilization. Meanwhile, the use of one-way feedback flow also minimizes the control traffic overhead. The stability, controllability and observability of this protocol are proven using control theory analysis. Simulation and numerical analysis also verified the favorable system behavior and performance.; The basic scheme is extended to improve its responsiveness and to enable multicasting ABR services. The Enhanced FlowNet protocol combines a mechanism for forward bandwidth request, a two-level fairness criterion for bandwidth allocation and a branch synchronization and consolidation algorithms for point-to-multipoint ABR connections. The complexity and performance analysis carried out demonstrates that the FlowNet protocols provide a complete, effective and unified solution for ABR service flow control, which has comparable complexity as other proposed explicit rate ABR flow control schemes but has better performance in high-speed backbone ATM networks. |
