The Cisco Interface Flexibility (I-Flex) design combines shared port adapters (SPAs) and SPA Interface Processors (SIPs) to help enable service prioritization for voice, video, and data services. Enterprise and service provider customers can take advantage of improved slot economics resulting from modular port adapters that are interchangeable across Cisco routing platforms. The extensible Cisco I-Flex design maximizes connectivity options and offers superior service intelligence through programmable interface processors that deliver line-rate performance. Cisco I-Flex enhances speed-to-service revenue and provides a rich set of Quality of Service (QoS) features for premium service delivery while effectively reducing the overall cost of ownership.The Cisco 1-Port OC-48c/STM-16c POS/RPR SPA is available on high-end Cisco routing platforms and offers the benefits of network scalability with lower initial costs and easy upgrades. The SPAs continues the Cisco focus on investment protection along with consistent feature support, broad interface availability, and leading-edge technology.