Cisco QSFP-ELR4-40G Compatible QSFP+ 40GBASE-ELR4 1310nm 20km DOM Duplex LC/UPC SMF Optical Transceiver Module

Overview

This is a high-performance, MSA-compliant optical transceiver module, fully compatible with the Cisco QSFP-ELR4-40G. It is specifically engineered for extended-reach 40-Gigabit Ethernet applications. This module provides a robust and cost-effective solution for data center interconnects, campus backbones, and service provider networks that require stable 40G links over longer distances than standard LR4 optics can provide.

The 40GBASE-ELR4 QSFP+ module leverages CWDM (Coarse Wavelength Division Multiplexing) technology. It integrates four separate 10G data lanes, each on a different wavelength, which are multiplexed and transmitted over a single pair of single-mode fibers. This advanced design enables reliable 40Gbps data transmission up to an extended distance of 20km, making it a critical component for modern, high-capacity network architectures.

Key Features

• 100% compatible with systems coded for Cisco QSFP-ELR4-40G.
• Supports an aggregated data rate of 41.2 Gbps (4 x 10.3 Gbps lanes).
• Extended Reach (ELR4) standard for links up to 20km over Single-Mode Fiber (SMF).
• Utilizes 4 CWDM uncooled DFB lasers on a 1310nm window grid.
• Features a standard Duplex LC connector for easy deployment.
• Hot-pluggable QSFP+ MSA-compliant form factor for seamless upgrades.
• Integrated Digital Optical Monitoring (DOM/DDM) for real-time diagnostics.
• Low power consumption (< 3.5W) for energy-efficient operation.

Applications

The extended 20km reach of the QSFP-ELR4-40G compatible module makes it ideal for specific, high-value network scenarios. Its primary use is in Data Center Interconnects (DCI) that link separate facilities across a metropolitan area. It is also perfectly suited for creating high-speed backbones in large university or corporate campuses and for aggregation links in service provider and telecom networks where standard 10km optics are insufficient.

Specifications

Cross-Platform Compatibility

While being a perfect alternative for the Cisco QSFP-ELR4-40G, this versatile module is built on Multi-Source Agreement (MSA) standards. This foundation ensures broad interoperability with a wide range of networking equipment from other major manufacturers. Below is a list of potential equivalent part numbers this module can successfully replace:

Advantages

The primary advantage of using this 40GBASE-ELR4 QSFP+ module is the significant reduction in capital expenditure. It delivers the same performance and reliability as OEM transceivers at a fraction of the cost, allowing for the expansion of network capacity while adhering to strict budgets. This makes high-speed, long-distance connectivity more accessible for a wider range of projects.

Additionally, the 20km reach capability eliminates the need for expensive and complex optical amplification or signal regeneration equipment on links between 10km and 20km. This simplifies network design, reduces potential points of failure, and lowers operational costs. The integrated DOM provides critical performance data, enabling network engineers to proactively manage and maintain the health of crucial long-haul links.

FAQ (Technical & Product Questions)

1. What is a 40GBASE-ELR4 QSFP+ module?

A 40GBASE-ELR4 QSFP+ module is a hot-pluggable optical transceiver that transmits 40G Ethernet data. The ‘ELR4’ designation signifies it is an ‘Extended Long Reach’ optic using four CWDM wavelengths to achieve distances up to 20km over single-mode fiber.

2. What is the difference between QSFP-40G-ELR4 and QSFP-40G-LR4?

The main difference is the reach. A standard LR4 (Long Reach) module is designed for distances up to 10km, whereas an ELR4 (Extended Long Reach) module, like this one, is engineered for longer distances up to 20km.

3. How does this QSFP+ module achieve a 40G data rate?

It uses four separate 10.3 Gbps transmitters, each on a distinct wavelength within the 1310nm window. These four optical signals are combined (multiplexed) onto a single fiber for transmission and separated (demultiplexed) at the receiving end, achieving an aggregate rate of 40Gbps.

4. What type of fiber optic cable is required for this 20km module?

To achieve the maximum distance of 20km, this transceiver requires a standard single-mode fiber (SMF) patch cable (OS1 or OS2) that is terminated with Duplex LC/UPC connectors.

5. Is this transceiver compatible with Cisco Nexus switches?

Yes, this optical module is specifically programmed and rigorously tested to ensure it is 100% compatible and functions seamlessly with Cisco networking equipment, including the Nexus series switches that support the QSFP-ELR4-40G part number.

6. What do the different wavelengths inside the ELR4 module do?

The four wavelengths (typically 1271nm, 1291nm, 1311nm, and 1331nm) each carry a separate 10G data stream. This CWDM technology allows a total of 40G to be sent over the same pair of fibers that would traditionally carry only a single signal.

7. Why is DOM important for a 20km transceiver?

Digital Optical Monitoring (DOM) is crucial for long-distance links because it provides real-time data on parameters like optical transmit/receive power, temperature, and voltage. This allows engineers to verify link health and quickly diagnose issues like fiber degradation or high attenuation over the 20km span.

8. Can I plug this 40G QSFP+ module into an SFP+ port?

No, the QSFP+ form factor is physically larger than an SFP+ port and is not electrically compatible. This 40G QSFP+ module must be used in a dedicated QSFP+ or QSFP28 port on a switch or network device.