SM321A | TP-Link Omada 1000Base-BX WDM Bi-Directional SFP Module – 20km Single-Fiber Transmission

The TP-Link SM321A is a high-performance WDM Bi-Directional SFP module, designed to extend your Gigabit fiber networks up to 20 kilometers over a single-mode fiber using only one fiber strand. Utilizing Wavelength Division Multiplexing (WDM), it transmits at 1550 nm and receives at 1310 nm, making it the perfect solution for cost-effective fiber deployment where fiber availability is limited.

Hot-swappable and fully compliant with SFP Multi-Source Agreement (MSA), the SM321A integrates seamlessly into a wide range of TP-Link Omada switches and third-party equipment that supports SFP modules. With DDM (Digital Diagnostic Monitoring) support, network administrators gain insight into real-time module performance and status.

What’s in the Box

• TP-Link SM321A WDM Bi-Directional SFP Module

• Installation Guide

Main Features

✅ WDM Bi-Directional Technology – Transmits and receives over a single fiber strand
✅ TX: 1550 nm / RX: 1310 nm – Matched for A-end usage in BX pair setups
✅ Up to 20km transmission over 9/125 μm single-mode fiber
✅ 1.25 Gbps data rate ideal for Gigabit Ethernet backhaul
✅ Hot-Swappable – Swap modules without powering down equipment
✅ DDM Support – Real-time monitoring of temperature, voltage, and optical signal
✅ LC Simplex connector for single-strand fiber connections
✅ Fully compliant with IEEE 802.3z, SFP-MSA, and RoHS

Detailed Specifications

Data Rate

• 1.25 Gbps

Wavelength

• TX: 1550 nm

• RX: 1310 nm

Fiber Type

• 9/125 μm Single-Mode Fiber

Max. Cable Length

• 20 km

Connector Type

• LC Simplex

Power Supply

• 3.3V

Form Factor

• SFP

Hot Swappable

• Yes

DDM Support

• Yes

Dimensions (W x D x H)

• 2.2 × 0.6 × 0.5 in (55.4 × 14.6 × 12.9 mm)

Certifications

• FCC, CE

Standards and Protocols

• IEEE 802.3z

• TCP/IP

• SFP-MSA Compliant

Warranty Information

Manufactures warrenty applied .

Brand Description

TP-Link Omada is a global leader in professional networking solutions, offering high-performance SFP modules tailored for both small business and enterprise-grade infrastructure. The SM321A enhances fiber efficiency and network scalability by delivering full-duplex Gigabit speeds on a single strand of fiber, reducing infrastructure costs while maintaining performance.

SKU

SM321A (TL-SM321A)

Practical Use Scenarios

🏢 Campus or Multi-Floor Office Networks – Ideal for connecting two locations via long-distance, single-fiber runs
📹 IP Camera Backhaul – Extend PoE switch uplinks to NVRs or core switches
🛠️ Limited Fiber Availability – Double fiber capacity by pairing with SM321B module on the opposite end
🚦 Smart City & Traffic Systems – Simplified point-to-point fiber for IoT sensors and cameras

Datasheets / Downloadable Resources

📄 SM321A datasheet

Excellence for the Australian and New Zealand Market

The SM321A is specifically sourced and distributed to meet Australian and New Zealand standards, with full compliance to FCC, CE, and RoHS certifications. This ensures interference-free operation, safe deployment, and product longevity under ANZ environmental conditions. Supplied exclusively by authorized TP-Link representatives, warranty handling and tech support are conducted directly within Australia and New Zealand, offering peace of mind for local businesses and IT professionals.

 FAQs

Q1. What fiber type is compatible with the SM321A module? (SM321A)
The SM321A supports 9/125 μm single-mode fiber, offering up to 20 km of transmission using LC simplex connectors.

Q2. Can the SM321A be paired with the SM321B module? (SM321A)
Yes, the SM321A is designed to work with SM321B in a WDM Bi-Directional setup for full-duplex communication over a single fiber.

Q3. What is the wavelength specification for the SM321A? (SM321A)
The SM321A transmits at 1550 nm and receives at 1310 nm.

Q4. Does the SM321A module support DDM? (SM321A)
Yes, it supports Digital Diagnostic Monitoring (DDM) to help track temperature, voltage, and optical power levels in real time.

Q5. Is the SM321A compatible with standard SFP ports on switches? (SM321A)
Absolutely, the SM321A is SFP-MSA compliant and works with all compatible TP-Link Omada switches and many third-party vendors.