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 thepay-as-you-populatemodel - 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 Cisco 100BASE-FX SFP The Cisco 100BASE-FX SFP operates on ordinary multimode fiber-optic (MMF) link spans up to 2 kilometers (km) long. GLC-FE-100FX modules operate in Fast Ethernet or dual-rate Fast/Gigabit Ethernet ports of Cisco switches and routers. GLC