Detailed Specifications
The Cisco QSFP-40G-LR4 is a 40GBASE-LR4 QSFP+ optical transceiver designed for high-speed, long-distance 40 Gigabit Ethernet connectivity in enterprise, service-provider, and data-center networking environments. The module operates over standard G.652 single-mode fiber (SMF) and supports link distances of up to 10 kilometers.
Unlike parallel-fiber 40G optics that require MPO/MTP cabling, the QSFP-40G-LR4 uses a conventional duplex LC fiber connection. The 40Gbps Ethernet signal is divided across four optical lanes and wavelength-division multiplexed onto a single fiber pair. The four nominal wavelengths are 1271 nm, 1291 nm, 1311 nm, and 1331 nm. Multiplexing and demultiplexing are performed internally by the transceiver. Cisco
Technical Specifications
| Specification | Details |
|---|---|
| Manufacturer | Cisco |
| Part Number | QSFP-40G-LR4 |
| Product Type | Optical transceiver module |
| Form Factor | QSFP+ |
| Ethernet Standard | 40GBASE-LR4 |
| Data Rate | 40 Gigabit Ethernet |
| Optical Architecture | Four wavelength-multiplexed optical lanes |
| Fiber Type | Single-Mode Fiber (SMF) |
| Fiber Standard | G.652 SMF |
| Connector Type | Duplex LC |
| Maximum Distance | 10 km / 6.2 miles |
| Nominal Wavelength | 1310 nm |
| Individual Wavelengths | 1271, 1291, 1311, 1331 nm |
| Transmit Power | -7 to +2.3 dBm per lane |
| Receive Power Range | -13.7 to +2.3 dBm per lane |
| Maximum Power Consumption | 3.5 W |
| Pull-Tab Color | Blue |
| Hot-Swappable | Yes |
| Electrical Interface | 40 Gigabit Ethernet QSFP interface |
| Optical Interface | Duplex single-mode LC |
| Standards | IEEE 802.3ba 40GBASE-LR4 |
| Primary Application | Long-range 40GbE network connections |









