Cisco SFP-25G-ER40-S-I Compatible SFP28 25GBASE-ER 1310nm 40km DOM Duplex LC/UPC SMF Optical Transceiver Module (Industrial)

Overview

This is an industrial-grade, high-performance 25G SFP28 ER optical transceiver, expertly engineered as a fully compatible alternative to the Cisco SFP-25G-ER40-S-I. Specifically, this module is designed for the most demanding networking environments. It combines a 25Gbps data rate with an extended reach (ER) of up to 40 kilometers, thereby providing a powerful solution for long-distance links. Furthermore, its industrial-grade rating ensures flawless operation under extreme temperatures, ranging from -40°C to 85°C.

Consequently, it is the definitive choice for mission-critical applications in uncontrolled environments such as outdoor enclosures, industrial plants, and 5G cell tower deployments. As a result of its advanced design, which includes a high-sensitivity APD receiver, this transceiver delivers the reliability and performance required for next-generation network upgrades and expansions.

Key Features

• 25GBASE-ER Performance: Fully compliant with the 25GBASE-ER standard, thus delivering a 25.78 Gbps line rate.
• Extended 40km Reach: Utilizes a high-power 1310nm EML laser and an APD receiver to achieve links up to 40km over single-mode fiber.
• Industrial Temperature Range: Built with hardened components to operate reliably in harsh temperature conditions from -40°C to 85°C (-40°F to 185°F).
• Guaranteed Compatibility: Functions as a seamless, plug-and-play replacement for the Cisco SFP-25G-ER40-S-I module.
• Digital Optical Monitoring (DOM): In addition to basic functionality, it provides real-time access to critical parameters like optical power, temperature, and voltage for proactive network management.
• Low Power Consumption: Designed for power efficiency, which is particularly important in high-density deployments.

Applications

The unique combination of high speed, long reach, and rugged construction makes this industrial SFP28 module essential for a variety of advanced applications. For instance, it is perfectly suited for:

• 5G Fronthaul and Midhaul Network Links
• Data Center Interconnects (DCI) over extended distances
• Industrial Ethernet and Factory Automation Networks
• Campus and Metropolitan Area Network (MAN) backbones
• Harsh Environment Carrier and Service Provider Networks
• Fiber to the Antenna (FTTA) deployments

Specifications

Cross-Platform Compatibility

In addition to being a perfect alternative for the Cisco SFP-25G-ER40-S-I, this versatile module is engineered based on Multi-Source Agreement (MSA) standards. For this reason, it offers broad interoperability with a wide range of equipment from other major manufacturers. Below is a list of potential equivalent part numbers this module can replace:

Advantages

By choosing this compatible SFP-25G-ER40-S-I module, you gain significant advantages. First and foremost, you achieve substantial cost savings compared to OEM parts without compromising on quality or performance. Moreover, each transceiver undergoes rigorous testing in its intended networking environment to guarantee 100% compatibility and reliability right out of the box. In practice, this means you can deploy these modules in your Cisco, Arista, or Juniper equipment with complete confidence. Ultimately, this approach frees you from vendor lock-in, providing greater flexibility and control over your network infrastructure and budget.

FAQ (Technical & Product Questions)

1. What is the main difference between SFP28 ER and SFP28 LR?

The primary difference is reach. “LR” stands for Long Reach, typically rated for 10km, while “ER” stands for Extended Reach, designed for much longer distances, in this case, 40km. This is achieved by using a more powerful laser (EML vs. DFB) and a more sensitive receiver (APD vs. PIN).

2. Why is an Industrial (-I) grade module necessary?

An industrial-grade module is essential for network equipment deployed in environments without climate control. Standard commercial-grade modules (0°C to 70°C) can fail in the extreme heat of a summer day or the freezing cold of winter. Consequently, industrial modules use hardened components to ensure stable operation from -40°C to 85°C, which is critical for reliability in outdoor cabinets, factory floors, or remote cell sites.

3. Can I plug this 25G SFP28 module into a 10G SFP+ port?

Yes, in most modern switches, a 25G SFP28 port is backward compatible with 10G SFP+ modules. However, you cannot get 25G speeds by plugging a 25G SFP28 module into a port that is only rated for 10G SFP+. The port determines the maximum speed.

4. What is 5G Fronthaul and why does it need 25G ER transceivers?

5G Fronthaul is the fiber link connecting the centralized Baseband Unit (BBU) to the Remote Radio Head (RRH) at the top of a cell tower. This link requires high bandwidth to carry the 5G signal, making 25Gbps the standard. Therefore, when cell towers are located several kilometers from the BBU, Extended Reach (ER) transceivers are required to cover the distance.

5. Does “40km” mean it will only work at that exact distance?

No, 40km is the maximum specified distance under ideal fiber conditions. The transceiver will work perfectly on any shorter link, from a few meters up to 40km. However, for very short links (e.g., within the same rack), an optical attenuator may be needed to avoid overloading the sensitive APD receiver.

6. What is an APD receiver and why is it used in ER optics?

APD stands for Avalanche Photodiode. It is a highly sensitive optical detector that can amplify the incoming light signal internally. This amplification is necessary to accurately detect the weak optical signal that remains after traveling a long distance like 40km, making APDs a key component for ER transceivers.

7. Is this module compatible with Cisco’s Forward Error Correction (FEC)?

Yes, this module is designed to operate correctly with host systems that implement FEC, such as RS-FEC (Reed-Solomon Forward Error Correction), which is common in 25G Ethernet standards to ensure error-free transmission over long distances.