QSFPliideseid

QSFP interfaces are a family of hot-swappable, high-density optical transceiver modules and the corresponding ports used to interconnect network devices. They provide high-bandwidth links between switches, routers, and storage systems, enabling 40 Gbit/s and higher data rates over short to long distances, depending on the variant. QSFP modules carry four electrical lanes and are designed to maximize port density in data centers and other high-performance networks.

Form factor and variants: The Quad Small Form-factor Pluggable (QSFP) design has evolved into several variants. QSFP+ typically supports 40 Gbps links. QSFP28 supports 100 Gbps. QSFP56 targets higher-rate, 200–400 Gbps-class links using advanced modulation. QSFP-DD is a double-density form factor that increases lane count to reach 400 Gbps and beyond, enabling higher aggregate bandwidth on a single port. Each variant preserves the basic four-lane or multi-lane concept but differs in per-lane speed and physical height.

Connectivity and optics: QSFP modules are used with both fiber and copper connections. Optical variants employ multimode or single-mode fiber with connectors such as LC or MPO/MTP, and are associated with link types like SR, LR, and ER. Copper variants use direct-attach copper (DAC) cables for short-range connections, typically within a rack or between nearby devices. Distances and compatibility depend on the specific QSFP type and the optical medium.

Applications and interoperability: QSFP interfaces are common in data centers, enterprise networks, and telecom backbones, supporting Ethernet, Fibre Channel, and InfiniBand in various form factors. They conform to multi-source agreement (MSA) standards to promote interoperability, though device firmware, vendor implementation, and module type influence compatibility and supported speeds on a given port. Proper cooling and adherence to electrical and optical specifications are important for reliable operation.