Cisco QSFP-40GE-LR4 Compatible 40GBASE-LR4 QSFP+ 1310nm 10km DOM Duplex LC SMF Optical Transceiver Module

Overview

This module is a high-performance, cost-effective QSFP+ optical transceiver, designed as a fully compatible alternative to the Cisco QSFP-40GE-LR4. It provides 40 Gigabit Ethernet connectivity for long-reach applications, supporting link lengths up to 10 kilometers over standard duplex single-mode fiber (SMF). This makes it an ideal solution for service provider transport links, Data Center Interconnects (DCI), and enterprise campus backbones.

The transceiver operates according to the 40GBASE-LR4 standard. It integrates four independent 10Gbps transmit and receive channels, which are multiplexed and demultiplexed within the module using a set of LAN-WDM (Local Area Network Wavelength Division Multiplexing) lasers. This advanced technology allows the full 40Gbps bandwidth to be transmitted over a single pair of fibers, terminated with a duplex LC connector. The “GE” in the part number simply emphasizes its use for Gigabit Ethernet and is functionally identical to the standard QSFP-40G-LR4.

Key Features

• 100% compatible with Cisco platforms that support the QSFP-40GE-LR4 module.
• Standard: Compliant with QSFP+ MSA and IEEE 802.3ba 40GBASE-LR4.
• Data Rate: 41.2 Gbps aggregate (4 x 10.3125 Gbps).
• Reach: Supports link lengths up to 10km on Single-Mode Fiber (OS2).
• Wavelengths: 4 LAN-WDM lanes: 1271nm, 1291nm, 1311nm, 1331nm.
• Connector: Duplex LC/UPC.
• Built-in Digital Optical Monitoring (DOM/DDM) for real-time diagnostics.
• Hot-pluggable QSFP+ form factor.

Applications

The QSFP-40GE-LR4 compatible module is built for:

• High-speed 40G Data Center Interconnects (DCI).
• Enterprise core and aggregation layer links.
• Service provider transport and backhaul networks.
• High-density 40G Ethernet switching and routing.
• Upgrading existing 10G long-haul links to 40G capacity.

Specifications

Cross-Platform Compatibility

Programmed for seamless integration with Cisco equipment, this module’s adherence to MSA standards ensures it can also be deployed in networking hardware from other major manufacturers that support 40GBASE-LR4 QSFP+ optics.

FAQ (Technical & Product Questions)

1. What is the difference between QSFP-40GE-LR4 and QSFP-40G-SR4?

The primary differences are their reach, fiber type, and connector. The LR4 module is for “Long Reach,” using single-mode fiber (SMF) with a duplex LC connector to achieve distances up to 10km. The SR4 module is for “Short Reach,” using multi-mode fiber (MMF) with an MPO connector for distances up to 150m (OM4). They are not interchangeable.

2. Can I use the QSFP-40GE-LR4 module for 4x10G breakout connections?

No. The 40GBASE-LR4 standard uses WDM technology to multiplex four 10G lanes onto a single fiber pair. It presents a single 40G interface and cannot be optically split into four separate 10G links. For breakout applications, you need a parallel optic module like the QSFP-4X10G-LR-S, which uses an MPO connector.

3. Is there a functional difference between QSFP-40GE-LR4 and QSFP-40G-LR4?

No, there is no functional difference. Both part numbers refer to the same 40GBASE-LR4 QSFP+ transceiver. The “E” in “40GE” is sometimes used to explicitly signify “Ethernet,” but the products are identical in performance and application.

4. What is LAN-WDM technology?

LAN-WDM (Local Area Network Wavelength Division Multiplexing) is a technology that uses four different light wavelengths (centered around 1310nm) to transmit four separate data streams over a single pair of optical fibers. The 40GBASE-LR4 standard uses LAN-WDM to combine four 10G data lanes into one 40G link.

5. What kind of fiber patch cable is needed for this module?

To connect two QSFP-40GE-LR4 modules, you must use a standard OS2 single-mode fiber patch cable with Duplex LC/UPC connectors on both ends. This will ensure proper alignment and low-loss connectivity for the 10km specified distance.