SFP-GE-S-2 and GLC-SX-MM are Cisco 1000BASE-SX SFP multimode fiber transceivers. Since there are similar specifications for these two multimode modules, many end users may be confused when choosing a multimode fiber SFP LC connector SX transceiver for their Cisco switches. So, are they the same one? This post intends to give a simple explanation of SFP-GE-S-2 vs. GLC-SX-MM.