See 1G SFP types—SX/LX/EX/ZX, BiDi, CWDM/DWDM, and 1000BASE-T—with distances, wavelength pairs, temp grades, and Cisco/Huawei/Ruijie examples. An SFP (Small Form-factor Pluggable) module is a compact, modular transceiver designed to connect network devices—such as switches, routers, and firewalls—to a transmission medium. In the case of 1G SFP modules, the supported data rate is 1 gigabit per second, commonly used for Gigabit Ethernet and. Use the tables below to pick the exact 1G SFP you need—then sanity-check with the ordering checklist at the end. How to Classify the SFP Transceivers? Color cues (if present) are not universal, but many vendors use: black = 850 nm MMF, blue = 1310 nm SMF, yellow = 1550 nm SMF. Use these transceivers for telecom applications such as enterprise access, metro aggregation, and broadband access, as well. Most 1G SFP failures are predictable: the module type does not match the switch lane wiring or optical budget, the fiber plant is worse than assumed, or the vendor's implementation of Digital Optical Monitoring (DOM) does not line up with the switch's interpretation. In one leaf-spine retrofit I. However, over the years, this technology has been increasingly adopted for shorter reach applications, such as Data-Center Interconnect (DCI) and 5G/6G front/backhaul, to overcome physical limitations of Intensity-Modulation/Direct-Detect (IM/DD) as those applications demand higher throughput.