Cisco Systems offers a family of Fast Ethernet (FE) port adapters optimized for the specific requirements of campus and enterprise backbones and data centers. The Cisco FE port-adapter options provide either one or two ports of 100BaseTX (copper) or 100BaseFX (fiber) Fast Ethernet ports per adapter. Each port can be configured for half- and full-duplex operation. Cisco Fast Ethernet port adapters may be used in an open port-adapter slot on Cisco 7200 Series routers or in an open bay within Cisco second- and fourth-generation Versatile Interface Processors (VIP2 and VIP4) on Cisco 7500 Series routers. Portability between these systems simplifies ordering and minimizes overall support and sparing costs.The PA-2FE-FX dual-port Fast Ethernet 100BaseFX adapter provides the highest packet throughput available for Cisco 7200 and 7500 Series routers. This adapter is the preferred choice for campus/enterprise backbones, data centers, campus-to-WAN connections, and high-performance routing between multiple Ethernet virtual LANs (VLANs).