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, 7500 and 7600 OSR series routers using 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 advanced ATM hardware features such as per-virtual circuit (VC) and per-virtual path (VP) traffic shaping, as well as support for most ATM service classes such as non-real-time Variable Bit Rate (nrt-VBR), Available Bit Rate (ABR) and Unspecified Bit Rate (UBR), and support of 4096 ATM VCs.This adapter is supported on VIP2-40 and VIP2-50 versatile interface processors.