Cisco 4x10GBASE-LR QSFP Modules for SMF — 40GBASE-LR-S QSFP+ Module

Upgrade your data center or enterprise network with the Cisco QSFP-4X10G-LR-S QSFP module, a high-performance, long-reach 40G optical solution designed for single-mode fiber. This engineering-grade transceiver delivers four independent 10 Gigabit Ethernet lanes in a compact QSFP+ package, enabling robust, scalable uplinks and core connectivity over standard G.652 SMF up to 10 kilometers. Built for reliability in demanding environments, it supports 40G optical links over parallel fiber terminated with MPO/MTP connectors and can seamlessly operate in a 4x10G configuration to maintain compatibility with legacy 10G networks. Whether you are consolidating data-center backbones, enabling high-bandwidth inter-switch links, or expanding campus networks, these LR-S modules provide the speed, reach, and interoperability you need without sacrificing ease of deployment.

• High-capacity 40G connectivity: The Cisco QSFP-4X10G-LR-S enables four independent 10G channels within a single QSFP+ footprint, delivering a total aggregated data rate of 40 Gbps while remaining interoperable with 10G Ethernet networks. This enables a scalable upgrade path for data centers and enterprise networks, reducing port density and simplifying cabling while maintaining strong performance for demanding workloads such as virtualization, SQL databases, and large-scale backups.
• Long-reach single-mode fiber support: Designed for G.652 single-mode fiber, this LR-S module supports link lengths up to 10 kilometers. That reach is ideal for data-center interconnects, campus networks, and metro deployments where distance and signal integrity are critical. You can reliably connect distant switches, routers, and servers without compromising data integrity or requiring repeaters or additional amplification.
• MPO/MTP fiber connectivity for high density: The module is intended for systems using 12-fiber MPO/MTP multifiber connectors. This enables parallel fiber termination for 40G links while preserving a clean, high-density cabling topology. The MPO/MTP capability helps maximize port density within switch chassis and distribution panels and supports clean, scalable cabling architectures in modern data centers.
• Interoperability with 10G networks: In addition to its native 40G operation, the QSFP-4X10G-LR-S can be used in a 4x10G mode, ensuring compatibility with legacy 10G optics and switches. This flexibility is invaluable when upgrading portions of a network gradually, maintaining seamless coexistence between old and new infrastructure while preserving existing investment and minimizing disruption.
• Reliable, hot-swappable form factor: As a Cisco QSFP+ transceiver, this module is designed for hot-swapping in compatible switches and routers, minimizing downtime during maintenance windows or upgrades. The compact QSFP+ package saves rack space and reduces cabling complexity, making it a practical choice for modern data-center architectures that demand high throughput with straightforward deployment.

Technical Details of Cisco 4x10GBASE-LR QSFP Modules for SMF

• Product name: Cisco QSFP-4X10G-LR-S
• Form factor: QSFP+ (Quad Small Form-factor Pluggable Plus)
• Data rate: 40 Gbps total (4 x 10 Gbps lanes)
• Wavelength: 1310 nm typical for LR-S operation
• Fiber type: Single-Mode Fiber (G.652)
• Distance support: Up to 10 kilometers on SMF
• Connector interface: 12-fiber MPO/MTP multifiber connector on the fiber side
• Operating environment: Designed for enterprise and data-center environments with reliable performance

How to install Cisco 4x10GBASE-LR QSFP Modules for SMF

• Prepare the equipment: Power down the device if required by your maintenance policy, or verify hot-swap capabilities on compatible switches or routers. Gather the appropriate MPO/MTP fiber assembly terminated for SR or LR configurations and confirm that the fiber is clean and free of debris.
• Remove the existing module (if applicable): If replacing an older transceiver, gently unlock and extract the current module from the QSFP+ slot, ensuring minimal force to avoid damage to the slot or neighboring modules.
• Inspect and align: Check the connector endfaces for cleanliness. Align the Cisco QSFP-4X10G-LR-S module with the slot orientation, ensuring that the handle or latch engages smoothly and seats firmly without excessive force.
• Insert the transceiver: Slide the LR-S module into the QSFP+ port until it clicks into place, then verify that the device recognizes the module. Most switches will display a status message or LED indicator confirming detection and link status.
• Connect the fiber cable: Use an MPO/MTP 12-fiber fiber assembly suitable for LR operation. Carefully align the MPO/MTP connector with the fiber interface on the transceiver and mate it securely. Ensure that the correct fiber polarity and pairing are maintained to support the four 10G lanes. Use appropriate fiber management practices to prevent bending and to minimize insertion loss.
• Verify operation and configure: Power on the system and verify link status via the command line or management interface. For 40G operation, verify that all four 10G lanes are active and that traffic is flowing correctly. If needed, apply the appropriate interface configurations to enable 40G mode or to maintain 4x10G mode depending on network design.

Frequently asked questions

• Q: What is the Cisco QSFP-4X10G-LR-S used for? A: It is a 40GBASE-LR QSFP+ transceiver that provides four 10G electrical lanes over a single 12-fiber MPO/MTP fiber link, designed for long-reach SMF links up to 10 kilometers.
• Q: What kind of fiber does it support? A: It supports single-mode fiber, specifically G.652 fiber, which is common in data centers and telecom networks for long-distance links.
• Q: How far can I run the link? A: The module supports up to 10 km on SMF, enabling efficient interconnects between data centers, campuses, or core network devices without repeaters.
• Q: Can I use it in a 4x10G configuration? A: Yes. In addition to full 40G operation, the module can operate in a 4x10G mode to maintain compatibility with older 10G networks and devices, providing flexible upgrade paths.
• Q: What connectors are used? A: The fiber side uses a 12-fiber MPO/MTP multifiber connector, which supports high-density deployments and clean cabling in modern data-center environments.
• Q: Is this module hot-swappable? A: Yes. The QSFP+ form factor is designed for hot-swapping in compatible network devices, enabling maintenance and upgrades with minimal downtime when performed according to your equipment’s guidelines.
• Q: Do I need any special configuration? A: In most cases, the module operates in Plug-and-Play fashion, but some network environments may require configuring interface speed or breaking out 40G into four 10G subinterfaces depending on switch capabilities and design.