The present invention provides for a system and method for data network control. Using a flow control system, embodiments of the present invention can analyze traffic flow volume and performance, incorporate usage, billing, and cost control data to yield an improved data network controller. Efficiency in data routing is improved while costs are decreased by enabling the selection of the optimal performance data route. Cost constraints and costs are minimized for an overall data load. Given a diverse set of cost structures for available transit providers, the overall system cost can be minimized by distributing traffic in a manner that takes advantage of the diverse billing structures and yet maintains acceptable performance levels. Systems and methods in accordance with embodiments of the present invention determine projected flow performance and projected flow volume in relation to the available bandwidth and marginal cost to a destination provider.