Cisco 1841 Integrated Services Router is part of the Cisco 1800 Integrated Services Router Series which complements the Integrated Services Router Portfolio. Cisco 1841 router offers embedded hardware-based encryption that enabled by an optional Cisco IOS Software security image. It delivers further enhancement of VPN performance with an optional VPN acceleration module; an intrusion prevention system (IPS) and firewall functions; interfaces for a wide range of connectivity requirements, including support for optional integrated switch ports; plus sufficient performance and slot density for future network expansion and advanced applications as well as an integrated real-time clock.