The Cisco ISR 3303 is an integrated SONET access platform that allows service providers to migrate to revenue-based IP services by lighting the access fiber with IP-intelligent Network Elements.The Cisco ISR 3303 is a carrier-class SONET access device that combines the powerful routing features of Cisco IOS with the ring access capabilities of a SONET Add/Drop Multiplexer (ADM). The Cisco ISR 3303 allows provisioning of native Time Division Multiplexing (TDM) services such as DS1 as well as next-generation, high-margin IP services using a single redundant platform deployed in the existing service provider access network.