Cisco-Compatible SFP-25G-LR SFP28 Transceiver Module

Overview

This module is a high-performance SFP28 optical transceiver designed as a fully compatible alternative to the Cisco SFP-25G-LR-S. It is engineered for long-reach 25 Gigabit Ethernet applications, providing a crucial link for next-generation network upgrades. The module adheres to the 25GBASE-LR standard, enabling reliable data transmission over distances up to 10 kilometers using standard single-mode fiber (SMF).

Operating with a high-performance 1310nm DFB laser, this transceiver is ideal for connecting switches, routers, and servers in enterprise campus backbones, data center interconnects, and service provider networks. The hot-pluggable SFP28 form factor allows for easy deployment and upgrades in existing network infrastructure. As an S-Class (“-S”) module, it is optimized for standard enterprise and data center operating environments, offering a robust and cost-effective solution for extending 25GbE networks.

Key Features

• 100% compatible with Cisco platforms that support the SFP-25G-LR-S module.
• Standard: Compliant with IEEE 802.3cc 25GBASE-LR and SFP28 MSA.
• Data Rate: Single-lane 25.78 Gbps.
• Reach: Supports link lengths up to 10km on Single-Mode Fiber (OS2).
• Wavelength: 1310nm DFB transmitter and PIN receiver.
• Connector: Standard Duplex LC/UPC.
• Host device requires RS-FEC (Reed-Solomon Forward Error Correction).
• Built-in Digital Optical Monitoring (DOM/DDM) for real-time diagnostics.
• Hot-pluggable SFP28 form factor.

Applications

The SFP-25G-LR-S compatible module is an excellent choice for a variety of long-distance, high-speed applications:

• Upgrades from 10G-LR to 25G-LR links.
• High-speed interconnects for data center core, aggregation, and Top-of-Rack (ToR).
• Enterprise campus and service provider transport applications.
• 5G front-haul and mid-haul mobile network infrastructure.

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 25G-LR SFP28 optics.

FAQ (Technical & Product Questions)

1. What is the difference between SFP-25G-LR-S and SFP-25G-SR-S?

The main difference is the application and fiber type. “LR” stands for Long Reach; the SFP-25G-LR-S uses a 1310nm laser to transmit up to 10km over single-mode fiber (SMF). “SR” stands for Short Reach; the SFP-25G-SR-S uses an 850nm laser to transmit up to 100m over multi-mode fiber (MMF). You must match the transceiver type to your fiber infrastructure.

2. Can I use this SFP-25G-LR-S module in a 10G SFP+ port?

Generally, no. The SFP-25G-LR-S is a single-rate module designed specifically for 25Gbps operation. Unlike some dual-rate SR modules (like the SFP-10/25G-CSR-S), it is not backward compatible with 10G SFP+ ports. It must be used in an SFP28 port that supports 25G speeds.

3. Does the 25GBASE-LR standard require Forward Error Correction (FEC)?

Yes. The IEEE 802.3cc standard for 25GBASE-LR mandates the use of RS-FEC (Reed-Solomon Forward Error Correction) on the host port (switch, router, NIC). The link will not function correctly without FEC enabled on both ends.

4. What does the “-S” class designation mean for this module?

The “-S” denotes an S-Class optic within the Cisco product line. These modules are specified for standard commercial temperature ranges (0°C to 70°C) and are intended for enterprise and data center applications, offering a balance of high performance and cost-effectiveness.

5. What specific fiber cable is required to connect two SFP-25G-LR-S modules?

To achieve the maximum 10km link distance, you must use an OS2 single-mode fiber patch cable terminated with Duplex LC/UPC connectors. Using multi-mode fiber will result in a non-functional link.