Cisco SFP-25G-ER-S Compatible SFP28 25GBASE-ER 1310nm 30km DOM Duplex LC/UPC SMF Optical Transceiver Module

Overview

This is a high-performance 25G SFP28 ER optical transceiver, engineered to be fully compatible with the Cisco SFP-25G-ER-S module. Specifically, it delivers a 25.78 Gbps data rate over extended distances. The module uses a high-power 1310nm EML laser to reach up to 30km without Forward Error Correction (FEC). Furthermore, with a host system that supports FEC, this reach can be extended up to 40km, thereby offering exceptional deployment flexibility. Consequently, this transceiver is an ideal and cost-effective solution for upgrading enterprise and data center networks to 25G Ethernet over long-haul fiber links.

Key Features

• High-Speed 25G Performance: Fully compliant with the 25GBASE-ER standard for a 25.78 Gbps line rate.
• Extended Reach Capability: Achieves up to 30km reach over SMF, and is extendable to 40km on systems utilizing RS-FEC.
• Advanced EML Laser: Employs a high-quality 1310nm EML transmitter and a sensitive APD receiver for superior long-distance signal integrity.
• Guaranteed Compatibility: Functions as a seamless, plug-and-play replacement for the Cisco SFP-25G-ER-S module.
• Digital Optical Monitoring (DOM): In addition, it provides real-time monitoring of key parameters like Tx/Rx power, temperature, and voltage.
• Low Power Consumption: Features an efficient design, consuming less than 2.0W of power, which is crucial for high-density applications.

Applications

The combination of high bandwidth and long reach makes this module exceptionally versatile. For instance, its primary applications include:

• Data Center Interconnects (DCI)
• 25G Ethernet and Enterprise Core Networks
• 5G Midhaul and Backhaul Deployments
• Campus and Metropolitan Area Network (MAN) backbones
• Service Provider and Carrier Networks

Specifications

Cross-Platform Compatibility

In addition to being a perfect alternative for the Cisco SFP-25G-ER-S, 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

Choosing this compatible SFP-25G-ER-S module delivers immediate and significant benefits. First and foremost, you can expect substantial cost savings compared to overpriced OEM modules. This allows you to reallocate your budget to other critical areas of your network. Moreover, every module undergoes rigorous testing in real-world environments. This guarantees 100% compatibility and flawless performance from the moment it is plugged in. Ultimately, you gain network flexibility, breaking free from vendor lock-in and enabling a more agile and cost-effective infrastructure strategy.

FAQ (Technical & Product Questions)

1. What is the difference between the 30km and 40km reach specifications?

This module can transmit up to 30km over single-mode fiber without any error correction from the host device. However, if the switch or router supports RS-FEC (Reed-Solomon Forward Error Correction), it can correct signal errors. As a result, this allows the link to be reliably extended up to 40km. The host device’s capabilities determine the maximum usable distance.

2. What does the “-S” in SFP-25G-ER-S signify for Cisco?

For Cisco products, the “-S” suffix typically designates that the module is part of the “S-Class” optics family. These modules are built to meet industry standards (MSA) and offer a more cost-effective option for enterprise and data center applications, as opposed to the carrier-grade “service provider” optics that may have additional proprietary features or wider temperature ranges.

3. What is an EML laser and why is it used for ER optics?

EML stands for Electro-absorption Modulated Laser. It combines a laser diode with an electro-absorption modulator in a single chip. This design allows for higher-quality signal transmission with less dispersion over long distances compared to a Direct Modulated Laser (DML). Consequently, EMLs are essential for achieving the extended reach (ER) required for 25G links of 30-40km.

4. Is this SFP28 module backward compatible with 10G SFP+ ports?

No, you generally cannot plug a 25G SFP28 transceiver into a port designed only for 10G SFP+ and expect it to work. However, most modern 25G SFP28 ports are backward compatible, meaning you can plug a 10G SFP+ transceiver into a 25G port and it will operate at 10G speed. Always check your host device’s documentation for compatibility specifics.

5. What is Forward Error Correction (FEC)?

FEC is a digital signal processing technique used to enhance data reliability. It adds redundant data (parity bits) to a message before transmission. The receiving device can then use this redundant data to detect and correct a certain number of errors that may have occurred during transit. For this reason, it is crucial for maintaining signal integrity on high-speed, long-distance links.

6. Can I use this ER (Extended Reach) module for a short link, like 1km?

Yes, you can. However, the powerful laser in an ER transceiver can overload the sensitive receiver on very short links, potentially causing errors. For links under 2km, it is best practice to use an optical attenuator to reduce the signal strength to a safe level for the receiver. This ensures optimal performance and protects the hardware.