TP-Link Single-Mode WDM SFP Module

TP-Link TL-SM321A | Single-Mode WDM SFP Module

The TP-Link Gigabit Single-Mode WDM Bi-Directional SFP Module (TL-SM321A) delivers reliable 1000BASE-BX fibre connectivity over a single strand of fibre, using wavelength-division multiplexing to transmit data in both directions simultaneously. Designed for network extensions up to 10 km, it’s ideal for long-distance links where fibre infrastructure is limited.

Quick Specs

Long-Distance Fibre Connectivity

The TL-SM321A uses advanced WDM technology to send and receive data over a single strand of single-mode fibre. By transmitting at 1550 nm and receiving at 1310 nm, it maximises fibre utilisation without requiring separate transmit and receive fibres, making it perfect for campus or building-to-building links where fibre is scarce.

Hot-Swappable & Easy Integration

With hot-swap capability and standard SFP form factor, this module slots directly into any compatible networking equipment without powering down the system. Its IEEE 802.3z compliance ensures broad compatibility with enterprise switches, routers, and media converters that support 1000BASE-BX.

Robust Environmental Performance

Built to operate reliably in challenging environments, the TL-SM321A functions between 0 °C and 70 °C, with storage tolerance from -40 °C to 80 °C. It also withstands relative humidity from 10 % to 90 % during operation, making it suitable for industrial, outdoor, or unheated premises.

CE & RoHS Certified

This module meets CE and FCC certification requirements and complies with RoHS standards for restricted substances, ensuring it adheres to UK and EU regulatory frameworks for safe operation and environmental responsibility.

Box Contents

• TP-Link TL-SM321A SFP module
• Product documentation

Before You Order

• Confirm your networking equipment supports 1000BASE-BX SFP modules.
• Verify your existing fibre infrastructure uses single-mode 9/125 µm cable.
• Check wavelength compatibility if pairing with third-party WDM equipment.
• Ensure your operating environment stays within 0–70 °C for reliable performance.

Questions and answers

The bottom line

The TP-Link TL-SM321A is a dependable choice for extending Gigabit Ethernet over long single-mode fibre runs where space and infrastructure are limited. Its WDM bi-directional design, hot-swap capability, and environmental resilience make it suitable for enterprise, industrial, and service-provider applications. Covered by the applicable manufacturer warranty.