The Enhanced ATM Port Adapter is a new generation of single-wide, single-port ATM port adapter for the Cisco 7200 and 7500 high-end routers that introduces many new ATM hardware and software features. Supporting DS3, E3, OC3c/STM1 Multimode, OC3c/STM1 Singlemode Intermediate Reach, and OC3c/STM1 Singlemode Long Reach interfaces - a total of five hardware versions - these new ATM port adapters are designed for a wide-range of ATM applications.The ATM PA-A3 includes a comprehensive ATM feature set including per-VC traffic shaping, support for many ATM Services Classes (nrt-VBR, ABR, and UBR), a new high-performance SAR architecture and support for a very large number of ATM virtual connections. All of these features are based on industry specifications and standards. In addition, the ATM PA-A3 works in conjunction with the Cisco 7500 and 7200 concurrent support for a wide range of port adapter technologies as well as Cisco's industry leading Cisco IOS protocols, services and ATM-rich feature set.