SFP 1.25Gb/s can be regarded as the upgrade version

Cisco Transceiver Modules support Ethernet, Sonet/SDH and Fibre Channel applications across all Cisco switching and routing platforms. The SFP 1.25Gb/s is defined by a multi source agreement between some manufacturers in the industry.GLC-SX-MM is a Cisco 1.25G, Gigabit multimode fiber optic module, which is available for multi-mode fiber optic cables with transmission distance up to 550m, It is also the industry standard Cisco 1000Base-SX Gigabit Ethernet SFP 1.25Gb/s, Currently on the market there are many non-genuine, the following text will tell you how to identify true and false Cisco GLC SX MM modules. Except for the original GLC-SX-MM module, many qualified fiber optic transceiver manufacturers producing the compatible GLC-SX-MM which will work well with all Cisco equipments just as the original ones, but the price is much more cheaper, and also widely accepted by customers. Cisco GLC-SX-MM Compatible 1000BASE-SX SFP 850nm module, SFP 1.25Gb/s, LC connector SX transceiver, features are as below