The Cisco 4-Port FE SPA is available on high-end Cisco routing platforms, offering the benefits of network scalability with lower initial costs and ease of upgrades. The Cisco SPA/SIP portfolio continues the company's 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, etc.) on the same interface processor.Fast Ethernet interfaces are commonly used to interconnect routers or other devices within a central office or data center or in a metropolitan-area network (MAN). With Cisco FE SPAs, users can mix and match SPA ports with other types of interfaces in the same slot. Each SPA provides standards-based Fast Ethernet implementation for compatibility and interoperability.