A functionality and method for determining aggregate data transit bandwidth requirements for the nodes of an Ethernet ring network for traffic management and to improve the operation, efficiency, and Quality of Service. An aggregate bandwidth database is produced, based on a priori knowledge of the ring network, including topology, path utilization, bandwidth sharing, and failure protection scenarios. Aggregate bandwidth requirements are determined independent of the actual real-time data traffic rates, and without requiring any actual real-time data traffic rate information. Aggregate bandwidth is automatically determined upon configuration or reconfiguration of the ring network.