TL-SM321B-2 | 1000Base-BX WDM Bi-Directional SFP Module

The TP-Link TL-SM321B-2 is a high-performance WDM bi-directional SFP transceiver designed for reliable Gigabit fiber networking. It adopts the 1000Base-BX standard and enables data transmission over a single strand of single-mode fiber, significantly reducing cabling cost and simplifying network deployment. Supporting a transmission distance of up to 2 km over 9/125 μm SMF, it is ideal for short to medium-range connections between buildings, offices, and campus environments. The module complies with the SFP Multi-Source Agreement (SFP-MSA), ensuring wide compatibility with switches, routers, and other networking equipment that support standard SFP ports. It operates using a paired wavelength system of 1310 nm for transmission and 1550 nm for reception, ensuring stable and efficient full-duplex communication.

In addition, the TL-SM321B-2 features Digital Diagnostic Monitoring (DDM) based on the SFF-8472 standard, allowing real-time monitoring of key parameters such as optical power, temperature, and operating current. This helps network administrators easily track performance and maintain network stability. The module is hot-swappable, enabling installation or replacement without shutting down the system, which minimizes downtime and improves maintenance efficiency. With its compact SFP design, plug-and-play capability, and strong compatibility, the TL-SM321B-2 provides a cost-effective and reliable solution for extending high-speed Gigabit Ethernet networks in enterprise and campus deployments.