The Cisco 100BASE-X Small Form-Factor Pluggable (SFP) device (Figure 1) is a hot-swappable input/output device that plugs into Fast Ethernet ports, dual-rate Fast/Gigabit Ethernet ports, or Gigabit Ethernet ports of a Cisco switch or router, linking the port with the fiber cabling network. Main features include the following: ● Hot-swappable when deployed, the switch or router does not have to reboot ● Supports the “pay-as-you-populate” model ● Interchangeable with other 100BASE-X SFPs on the same line card ● Supports the Cisco quality ID feature that enables the switch or router to identify whether or not the SFP is a Cisco qualified SFP ● Optically interoperable with respective 100BASE-X Ethernet interfaces on the same link