The 100GBASE-LR4 QSFP28 transceiver is designed for long-haul fiber optic communications and is widely used in high-performance networks. It works with single-mode fiber (SMF) and can cover distances of up to 10 kilometers, making it the best choice for LC SMF optical transceiver. Whether you're upgrading a workstation, scaling a small business network, or building out a hyperscale data center, a fiber network card (NIC, network interface card) is one of the most critical components for connectivity. Copper Ethernet NICs still have their place, but when bandwidth, distance. There is a 100G QSFP28 transceiver for any distance requirement: starting from a close quarters connection in a datacenter to long distance connections to nearly 100 kilometers to 100G Lambda. Altogether, there are a lot of 100G QSFP28 variants, but the main ones are SR4 (Short Range, 100m), CWDM4. The Cisco 100GBASE Quad Small Form-Factor Pluggable (QSFP) portfolio offers customers a wide variety of high-density and low-power 100 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider. The QSFP28 (Quad Small Form-factor Pluggable 28) is the industry-standard form factor for 100 Gigabit Ethernet (100GbE) and high-speed data center interconnects. However, selecting between different interface types like SR4 or PSM4 requires a careful technical evaluation.