The Cisco ASR 1000 Series SPA Interface Processor (SIP), based on the Cisco I-Flex design, combines shared port adapters (SPAs) and SPA interface processors (SIPs), taking advantage of an extensible design that facilitates service prioritization for voice, video, and data (triple-play) 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 Cisco ASR 1000 Series SIP accepts up to 4 half-height Cisco SPAs, including Ethernet, ATM, Packet over SONET/SDH (POS), and Serial SPAs, providing up to 10-Gbps connection to the system backplane with an ability to differentiate traffic based on Layer 2 or Layer 3 header information.