Cisco SFPs can meet Cisco users’ different needs, GLC-SX-MMD, the 1000BASE-SX SFP, can support up to 1km over laser-optimized 50 μm multimode fiber cable; GLC-LH-SM, Cisco 1000BASE-LX/LH SFP transceiver module, operates on standard single-mode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers; GLC-T over unshielded tw...