The Cisco 1721 is a modular router optimized for data-access applications, providing businesses with the most complete functionality and flexibility to deliver secure Internet and Intranet access. The router offers a wide array of WAN access options, high-performance routing, Quality of Service, inter-virtual LAN routing, and VPN access with firewall options. Powered by Cisco IOS, the Cisco 1721 offers high reliability and flexibility of interchangeable WAN interface cards, comprehensive security that includes hardware-assisted VPN encryption and a stateful inspection firewall, and business-class DSL with enhanced quality of service to ensure high-performance levels are guaranteed.