The Cisco® I-Flex approach combines shared port adapters (SPAs) and SPA interface processors (SIPs), providing an extensible design that enables service prioritization for data, voice, and video 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 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. This data sheet contains the specifications for the Cisco 4-Port and 8-Port 10BASE-T/100BASE-TX Fast Ethernet Shared Port Adapters, Version 2

The Cisco Fast Ethernet SPAs are available on high-end Cisco routing platforms, offering the benefits of network scalability with lower initial costs and easy 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 Fast Ethernet 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.

Applications
The Cisco Fast Ethernet SPAs can be used in any combination of the following applications:

- Residential triple-play services
- Metro Ethernet services
- Converged residential and business services
- Internet peering
- Inter- and intra-point of presence (POP) aggregation