In response to the growing demand for improved ip quality of service (QoS) support over ATM networks, the Cisco 12000 gigabit switch router (GSR) has extended its IP class-of-service (CoS) capabilities for end-to-end deployment across ip and traditional ATM networks. Via a simple microcode upgrade, the existing quad-port OC-3 line cards, allow network managers to provide differentiated CoSs over integrated IP and ATM networks.The Cisco 12000 GSR quad-port OC-3 ATM line cards feature a high-performance programmable (SAR), adapted for a number of different applications to include advanced traffic management, cell scheduling, and integrated buffer management. The programmable nature of the SAR allows the firmware and data structures to be customized for specific network applications, and evolve as new standards become available. This latest SAR firmware revision or microcode, allows network managers to configure per-VC queuing, per-VC traffic shaping, and IP to ATM CoS - for support of advanced traffic management and QoS capabilities. Service providers can leverage these features today, provisioning multiple service classes across IP and traditional ATM networks. By mapping IP CoS to ATM QoS on the GSR ATM line cards, the flow of mission-critical data can be effectively managed across heterogeneous IP and ATM networks.