In fiber optic communications, SR LR LRM ER and ZR are terms that stand for 10g modules transmission distance. Let us see that the case of Multimode Fiber 10GBase-SR. High-speed data transmission in enterprise and data center networks is driven by 10G optical modules. Choosing the proper SFP+ module, whether it be SR, LR, or ER, can have significant impacts on performance, reliability, and costs. Knowing the key differences, compatible fiber types, and correct. DWDM (Dense Wavelength Division Multiplexing): Combines multiple wavelengths (C-band or L-band) on a single fiber for high-capacity transport. Standards governing 400G Ethernet (802. 3bs), FlexE, and CAUI-4 interfaces. The transmission distance they represent is from short to long.