Introduction: What is 100GBASE-ER4 Optical Module?
The 100GBASE-ER4 optical module is another critical component in the high-speed Ethernet ecosystem, designed to provide 100Gbps of data transfer over even longer distances than the 100GBASE-LR4. With a range of up to 40 kilometers, the 100GBASE-ER4 is built for ultra-long-haul optical networks, making it ideal for applications that require extensive reach, such as interconnecting distant data centers and long-distance telecommunications networks.
The Features of 10GBASE-SR, 40GBASE-SR4, and 100GBASE-ER4
The 100GBASE-ER4 is designed to push the boundaries of Ethernet connectivity even further than the 100GBASE-LR4, supporting a transmission distance of up to 40 kilometers over single-mode fiber:
- 10GBASE-SR: Limited to short distances (up to 300 meters) with a 10Gbps data rate.
- 40GBASE-SR4: Supports 40Gbps over a distance of up to 150 meters.
- 100GBASE-ER4: Offering a data rate of 100Gbps, it can span distances of up to 40 kilometers, making it ideal for metropolitan and wide-area networks (MANs and WANs) that need extensive reach.

The 100GBASE-ER4 leverages CWDM technology and four wavelengths to support high-speed, long-distance data transfer.
Applications of The High-Speed Standards in Modern Networking
The 100GBASE-ER4 is particularly well-suited for networks that need to cover vast distances without compromising on speed:
Telecommunications: Telecom providers use the 100GBASE-ER4 for long-distance fiber-optic networks, delivering high-speed internet across cities and even regions.
Wide-Area Networks (WANs): Large-scale WAN deployments can benefit from the 100GBASE-ER4, providing high-performance connectivity across long distances.
Inter-Data Center Connections: When data centers are located far apart, the 100GBASE-ER4 allows for seamless data transfer across long stretches of fiber, ensuring fast, reliable communication.
Cloud Services: For cloud providers that manage data across multiple geographic locations, the 100GBASE-ER4 module ensures that data is transmitted rapidly and efficiently across extensive distances.
How It Works: The Technology Behind These Ethernet Standards
The 100GBASE-ER4 works similarly to the 100GBASE-LR4, but it takes the distance capabilities to the next level. By using Coarse Wavelength Division Multiplexing (CWDM) technology, the 100GBASE-ER4 uses four distinct wavelengths, each transmitting at 25Gbps, to deliver 100Gbps throughput across long distances. The key difference is the extended range—up to 40 kilometers—enabled by single-mode fiber.
The 100GBASE-ER4 is an optical transceiver that ensures high-performance, long-distance connectivity, making it perfect for telecom networks, data center interconnections, and wide-area networks.
Comparative Analysis: Choosing Between 100GBASE-LR4 vs. 100GBASE-ER4 for Your Network Needs
Choosing between 100GBASE-LR4 and 100GBASE-ER4 involves considering both speed and distance:
Feature | 100GBASE-LR4 | 100GBASE-ER4 |
Data Rate | 100Gbps | 100Gbps |
Transmission Distance | Up to 10 kilometers | Up to 40 kilometers |
Fiber Type | Single-mode fiber (SMF) | Single-mode fiber (SMF) |
Wavelengths | 4 | 4 |
Use Case | Ultra-long range applications | Long-range, high-performance networks |
The 100GBASE-ER4 is the clear choice for networks requiring long-distance data transmission. With its range of up to 40 kilometers, it is designed to meet the needs of large-scale telecom and WAN networks.
Conclusion: Embrace the Future of Networking with a Deeper Understanding of Ethernet Standards
The 100GBASE-ER4 module represents the future of high-speed, long-distance networking. Whether for telecom, cloud, or data center interconnection, it provides the high-performance, long-range solution that modern networks need to thrive. Embrace the potential of 100GBASE-ER4 and ensure your network is equipped to handle the growing demand for bandwidth across vast distances.