Long-distance variants, typically referred to as LX, EX, ZX, or ER/LR SFPs, are engineered with higher optical power budgets and longer wavelength lasers (e., 1310nm, 1550nm), enabling transmission distances from 10 km up to 80 km or more over single-mode fiber (SMF). SFP (Small Form-factor Pluggable) modules are standardized network transceivers that support a range of data rates (1G, 10G, 25G) and fiber types. 100 Gbps coherent modules based on the ZR specification debuted in 2017. 5 watts per 100G of data delivered. Microsoft became an early adopter and used the. The QSFP28 LR4 is a hot-pluggable, four-channel, and full-duplex optical transceiver module designed for long-distance transmission up to 10 km in the 100G Ethernet network with a working bandwidth of 1295nm to 1310nm. Understanding the basic differences between each module is important to prevent an expensive misconfiguration and provide you with the best network. The 1550nm window has become the mainstream choice, and single-mode fiber has become essential in replacing multimode fiber. Behind this wavelength selection is the lowest attenuation region of silica fiber, which allows signals to be transmitted over longer distances without the need for repeaters. At a wavelength of 850nm, a 100M optical module can transmit up to 2km, a 1G can transmit up to 550m, a 10G can transmit up to 300m, a 40G can transmit up to 400m, and 100G and 400G can transmit up to 100m.