<P> The Cisco Systems industry-standard Asynchronous Transfer Mode (ATM) DS3 module supports traffic shaping and traffic policing on a permanent virtual circuit (PVC) basis. This advanced functionality provides the ability to offer and enforce varying levels of class of service (CoS). </P> <P> Using this module, network administrators can segment bandwidth based upon the virtual LAN (VLAN) identity of the data and gain control over traffic patterns within their network - a powerful tool. Because the ATM DS3 module can be used in any Catalyst<SUP>®</SUP> chassis, customers can deploy Catalyst switches as ATM edge devices where wirespeed traffic policing and traffic shaping is needed. </P>