Today, for a growing number of small and medium businesses, networks are at the heart of their ability to communicate with and be responsive to their customers, suppliers, and employees. This scenario is driving the demand for networks to be available 24 hours a day, 7 days a week. While software and hardware redundancy have long been a requirement for the core networks of large companies, increasingly both their smaller offices and offices of small and medium-sized businesses have the same needs. On products for small and medium-sized offices, Cisco Systems has long met the requirement for software redundancy with Cisco IOS features such as Hot Standby Routing Protocol (HSRP). To meet the need in these offices for power redundancy, Cisco is adding redundant power as an option across a range of Cisco routers, switches, hubs and access servers.This is the field upgrade to take any 2500 series AC powered router and give it a DC input so it will be capable of using the DC RPS that Cisco has.