Cisco's eight-port serial port adapter (PA-8T) delivers high-density WAN connectivity for enterprise and service provider networks. It provides up to eight full-duplex serial interfaces for the Cisco routers. The eight-port adapter requires only a single slot in a Cisco 7200 Series router. For Cisco 7500 Series routers, it requires one of the two available adapter slots on a Versatile Interface Processor (VIP2). Its high density doubles the number of available ports in the same space as the four-port adapter (PA-4T+). This enables up to sixteen ports per chassis slot in VIP2-based systems.The eight-port adapter offers unmatched flexibility. Network administrators can provision eight T1 (1.55 Mbps) or E1 (2.048 Mbps) ports, four ports delivering speeds up to 4 Mbps, or two ports delivering speeds up to 8 Mbps (E2). Three models of the PA-8T provide eight ports of either V.35, EIA/TIA-232 or X.21 electrical interfaces. A single eight-port fan-out cable provides connection to the PA-8T, simplifying cabling requirements. High port density, a low cost per port, and high-performance combine to deliver the highest possible network throughput while minimizing network infrastructure costs.