The enhanced asynchronous transfer mode (ATM) port adapters (ATM PA-A3) are single-port, single and dual-wide ATM port adapters for the Cisco 7200 and 7500 series routers and the FlexWAN module for the Catalyst 6000 family of switches. The ATM PA-A3 is designed with a high-performance, dual segmentation and reassembly (SAR) architecture with local buffer memory.The ATM PA-A3 supports the latest ATM hardware features such as per-virtual circuit (VC) traffic shaping and virtual path (VP) traffic shaping, as well as support for such ATM service classes as non-real-time Variable Bit Rate (nrt-VBR) and Universal Bit Rate (UBR), and support of 4096 ATM VCs.