Cisco 40GBase-LR4L QSFP Module for SMF

Engineered for performance, efficiency, and reliability, the Cisco WSP-Q40GLR4L QSFP Module enables 40 Gigabit Ethernet connectivity over long-haul single-mode fiber. This LR4L transceiver is designed for dense data centers, cloud environments, and service provider backbones where scalable uplinks, low latency, and robust signal integrity matter. The device fits standard QSFP+ ports, providing a compact, hot-swappable solution that minimizes rack space and simplifies field upgrades. Four parallel 10 Gb/s lanes are multiplexed inside the module, delivering a total data rate of 40 Gbps while preserving signal quality across a link of up to 2 kilometers on G.652 fiber. The four wavelengths are multiplexed and demultiplexed within the transceiver, so the fiber plant remains cleaner and less complex, reducing splices, connectors, and patch panels. The duplex LC connectors support easy compatibility with widely deployed SMF cabling, making it straightforward to integrate with existing backbone networks and new deployments alike. The LR4L variant fronts a longer reach than traditional LR4, enabling more flexible topologies such as spine-leaf fabrics, data-center interconnects between buildings, and enterprise campus backbones. The module is designed to be plug-and-play with Cisco switches and routers that support QSFP+ LR4L modules, enabling rapid deployment, straightforward troubleshooting, and streamlined maintenance. In addition, the WSP-Q40GLR4L is built to meet stringent industry reliability requirements, featuring robust housing and thermal design that maintains performance in chassis with varying ambient temperatures and busy traffic patterns. For IT teams, the module delivers predictable bandwidth and predictable performance for latency-sensitive workloads, including virtualized workloads, high-performance computing, database acceleration, and multimedia streaming across distributed sites. By consolidating four 10G channels into a single, easy-to-manage transceiver, it reduces the number of active ports required and simplifies cabling strategies, offering cost-effective scalability as data demands grow. With Cisco's proven interoperability in mixed-vendor environments and its industry-leading device management ecosystem, administrators benefit from unified monitoring, simplified firmware updates, and streamlined support. This makes the Cisco 40GBase-LR4L QSFP Module an ideal choice for organizations seeking to maximize uplink bandwidth without sacrificing fiber efficiency, while preserving the flexibility to scale to even higher speeds in the future as data requirements evolve. Whether you're building a new data center or upgrading an existing network, the WSP-Q40GLR4L provides a dependable, high-performance 40G uplink that integrates with your Cisco backbone and ensures stable, high-throughput connectivity for a broad range of workloads and applications.

• Four-lane 40 Gigabit Ethernet over a single QSFP+ module delivering scalable bandwidth in data centers and enterprise networks.
• Long-reach capability: up to 2 km on standard G.652 single-mode fiber with duplex LC connectors for flexible backbone or data-center interconnects.
• Integrated mux/demux within the module for four wavelengths, simplifying fiber topology and reducing patching complexity.
• Compatibility with Cisco Nexus and Catalyst switches that support QSFP+ LR4L modules, enabling plug-and-play deployment and streamlined management.
• Energy-efficient design with a hot-swappable transceiver in a compact form factor, optimized for dense racks and multi-hop topologies.

Technical Details of Cisco 40GBase-LR4L QSFP Module for SMF

• Model: WSP-Q40GLR4L
• Form factor: QSFP+ hot-swappable transceiver
• Data rate: 40 Gb/s (4 x 10 Gb/s lanes)
• Fiber type: Single-mode fiber (G.652)
• Reach: Up to 2 km
• Connectors: Duplex LC
• Wavelength channels: Four channels for LR4 operation
• Internal multiplexing/demultiplexing: Integrated mux/demux within the module
• Compatibility: Designed for Cisco network devices that support QSFP+ LR4L modules

how to install Cisco 40GBase-LR4L QSFP Module

• Power down or follow vendor guidelines for safe insertion when working with active equipment.
• Align the WSP-Q40GLR4L module with the QSFP+ port and insert until it seats with a firm click.
• Attach the duplex SMF LC cables to the module’s LC connectors, ensuring proper polarity and clean, correct connections.
• Power on the device and verify the module is recognized in the switch fabric; configure the 40G uplink as LR4L if required by your network policy.
• Run basic diagnostics and monitor link status, throughput, and error counters to confirm a stable 2 km reach under expected fiber conditions.

Frequently asked questions

• What is the maximum reach of the Cisco 40GBase-LR4L QSFP Module? Up to 2 kilometers on G.652 single-mode fiber with duplex LC connectors.
• What fiber type does it require? Standard single-mode fiber (G.652).
• Is the module hot-swappable? Yes, it is designed as a hot-swappable QSFP+ transceiver for Cisco devices.
• Which devices support the WSP-Q40GLR4L? Cisco switches and routers with QSFP+ LR4L ports that support 40GBASE-LR4L modules.
• Does it include internal multiplexing? Yes—the module handles wavelength multiplexing and demultiplexing internally to simplify cabling.