The 4-Port OC-3c/STM-1 POS (Packet over SONET) SPA is available on high-end Cisco Systems routing platforms offering the benefits of network scalability with lower initial costs and ease of upgrades. The Cisco SPA/SIP portfolio continues the Cisco focus on investment protection along with consistent feature support, broad interface availability, and the latest technology. The Cisco SPA/SIP portfolio allows deployment of different interfaces (Packet over SONET/SDH [POS], ATM, Ethernet, and so on) on the same interface processor.