Cisco�s Catalyst 2900 Series XL is a full line of 10100 autosensing Fast Ethernet switches that offers outstanding performance, versatile modularity, and easy-to-use management. The Catalyst 2900 Series XL includes four models with different port densities, configuration options and pricing to meet a broad range of network design requirements.The Catalyst�2912MF XL switch has 12 100BaseFX ports. These ports use 10/125- or 62.5/125-micron multimode fiber-optic cabling. In full-duplex mode (the default), these ports connect to other 100BaseFX devices over distances of up to 2 kilometers. In half-duplex mode, the ports connect to devices up to 412 meters from the switch.Switches running standard software are designated by the letter A, and switches running Enterprise Edition Software are designated by the letters EN.