SFP-8G31-LW 8G SFP+ LW 1310nm 10km LC SMF DDM Transceiver Module

Overview

The SFP-8G31-LW is a high-performance, long-wavelength SFP+ optical transceiver module engineered for long-distance 8G Fibre Channel (8GFC) applications. As an “LW” (Long Wavelength) module, it utilizes a highly stable 1310nm DFB laser to reliably transmit data across Single-Mode Fiber (SMF) for distances up to 10 kilometers. This makes it the perfect solution for connecting SANs between different buildings, across a campus, or in metropolitan area networks. A critical feature is its multi-rate capability, ensuring full backward compatibility with older 4G and 2G Fibre Channel infrastructure, allowing for flexible and cost-effective network operation and upgrades.

Key Features

• • Long-Reach Connectivity: Capable of transmitting data up to 10km over standard single-mode fiber.
  • Multi-Rate Support: Auto-negotiates to support 8G, 4G, and 2G Fibre Channel data rates for maximum compatibility.
  • 1310nm DFB Laser: Employs a high-quality Distributed Feedback (DFB) laser for stable, long-distance transmission.
  • Hot-Pluggable SFP+ Form Factor: Adheres to the SFP+ MSA standard, enabling installation and replacement in live systems without service disruption.

*Digital Diagnostics Monitoring (DDM): Provides real-time monitoring of key operational parameters like Tx/Rx power, temperature, and voltage.

• Energy Efficient Design: Low power consumption helps reduce overall data center operational costs.
• Standard LC Interface: Equipped with a duplex LC connector for easy integration with existing SMF cabling infrastructure.

Applications

The SFP-8G31-LW is specifically designed for long-distance storage network links. Common applications include:

• SAN extension and campus area network (CAN) connectivity
• Connecting geographically separated data centers for disaster recovery
• Long-distance links between storage arrays and SAN directors
• 8G/4G/2G Fibre Channel infrastructure backbone

Technical Specifications

Advantages

The SFP-8G31-LW provides a robust and cost-effective solution for extending the reach of your Storage Area Network. It eliminates the need for expensive signal regeneration equipment for links up to 10km. Each module is rigorously tested for compatibility with a wide range of SAN equipment from major vendors like Brocade, Cisco, and others, guaranteeing reliable, plug-and-play performance. The inclusion of DDM is vital for long-distance links, as it allows network administrators to proactively monitor the link’s health and ensure the stability and uptime of mission-critical storage connections.

Product & Technical FAQs

1. What does LW stand for in SFP-8G31-LW?

LW stands for Long Wavelength. This indicates the module uses a longer wavelength laser, typically 1310nm or 1550nm, and is designed for long-distance transmission over Single-Mode Fiber (SMF).

2. What type of fiber optic cable is required to achieve the 10km distance?

To reach the maximum 10km distance, you must use standard Single-Mode Fiber (SMF), such as OS2, terminated with LC Duplex connectors.

3. What is the difference between an 8G LW and an 8G SW module?

The primary difference is the application. An LW (Long Wavelength) module, like this one, is for long distances (10km) over Single-Mode Fiber. An SW (Short Wavelength) module is for short distances (e.g., 150m) over Multi-Mode Fiber.

4. Is this 8G Fibre Channel module backward compatible?

Yes. The SFP-8G31-LW is a multi-rate module that will auto-negotiate and operate seamlessly with older 4G and 2G Fibre Channel equipment, protecting your existing hardware investment.

5. Can I plug this SFP+ module into a 10G Ethernet switch port?

No. Even though they use the same SFP+ physical form factor, 8G Fibre Channel and 10G Ethernet are different, incompatible protocols. This module must be used in a port that explicitly supports 8GFC.

6. What is a DFB laser and why is it used?

A DFB (Distributed Feedback) laser is a type of laser that provides a very stable, single-frequency output, which is essential for minimizing signal degradation over long distances. It is the standard for long-reach transceivers.

7. Is the SFP-8G31-LW hot-swappable?

Yes. The module is compliant with the SFP+ Multi-Source Agreement (MSA), which mandates that the device must be hot-swappable. You can install or remove it from a running system without causing a service interruption.

8. Why would I use 8G Fibre Channel when faster speeds exist?

8G Fibre Channel remains a widely deployed and cost-effective solution for many applications that do not require the absolute highest bandwidth. It is ideal for supporting legacy systems or for networks where 8G provides more than sufficient performance for the workload.