In an effort to resolve the existing problems in current ADSL （Asymmetrical Digital Subscriber Line） access network in terms of bandwidth allocation efficiency and QoS （Quality of Service）guarantee

we propose a new bandwidth allocation scheme

in which the Lagrangian optimization approach is applied. In this scheme

based on the online measuring data

the bandwidth assigned to different classes of traffics is adjusted under certain linear pricing strategy so that the network provider could realize the revenue maximization objective with resource constraints and the various QoS requirements of the customers could be met simultaneously.