This guide breaks down NS-branded QSFP28 modules—SR4, LR4, and DR—with practical advice on reach, fiber types, connectors, power, DOM, interoperability, and lifecycle management. As one of the most popular transceiver types in 100G Ethernet applications, the QSFP 100G LR4 offers a powerful combination of long reach, compact form factor, and compatibility with single-mode fiber networks. To better understand why it has become an industry standard, let's break down its. Is the LR4 a groundbreaking fourth-generation technology in telecommunications, offering a significant breakthrough, yet somehow more affordable than the seemingly older LR module? In this concise article, we'll clarify these differences, explain their implications, and guide you on how to use them. 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. It provides an ideal solution for large-scale data centers for high-demand. 400G QSFP-DD DR4, FR4, and LR4 are three optical transceiver architectures defined for 400-gigabit Ethernet, each optimized for different fiber infrastructures and reach requirements. DR4 uses parallel single-mode optics over MPO fiber, while FR4 and LR4 rely on CWDM wavelength multiplexing over. The electrical interface uses CAUI-4, which stands for 100 Gigabit Attachment Unit Interface 4-lane. This defines how the switch ASIC talks to the module.
