The Cisco GLC-FE-100FX is a 100BASE-FX SFP (Small Form-Factor Pluggable) transceiver module designed for Fast Ethernet connectivity over multimode fiber . It is a hot-swappable input/output device that plugs into Fast Ethernet, dual-rate Fast/Gigabit Ethernet, or Gigabit Ethernet ports of Cisco switches and routers, linking the port with the fiber cabling network .