The TP-Link SM321A Bi-Directional SFP module is designed for 1000BASE-BX Gigabit connections over single-mode fiber, ensuring reliable transmissions up to 20 km at speeds of 1.25 Gbps. Equipped with a simplex LC interface, it uses a Tx 1310 nm / Rx 1550 nm wavelength, ensuring compatibility with the SFP-MSA standard and IEEE 802.3z protocols. It integrates the DDM (Digital Diagnostic Monitoring) function for real-time monitoring of optical power, temperature and current, improving network management. The hot-pluggable design allows installation and replacement without service interruption, making it ideal for switches, routers and corporate servers. FCC and CE certified, it represents a safe and professional solution for modern LAN and WAN networks. Omada
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SM321A | 1000BASE-BX10-D LC BIDIRECTIONAL MINI-GBIC SFP MODULE

The TP-Link SM321A Bi-Directional SFP Module is designed for 1000BASE-BX Gigabit connections over single-mode fiber, ensuring stable transmissions up to 20 km at speeds of 1.25 Gbps. Compatible with the SFP-MSA standard and IEEE 802.3z protocols, it uses a simplex LC interface with a Tx 1310 nm / Rx 1550 nm wavelength. It integrates the DDM (Digital Diagnostic Monitoring) function for real-time monitoring of optical power, current, and temperature, improving network management. The hot-pluggable design allows for quick installation and replacement without service interruption, making it ideal for professional switches, routers, and servers.
Main specifications:
- Transmission up to 20 km on 9/125 µm single-mode fiber
- Data rates up to 1.25 Gbps
- Digital Diagnostic Monitoring (DDM) support
- Compatibility with SFP-MSA and IEEE 802.3z standards
- Hot-Pluggable design for operational flexibility
Further details
Technical data sheet
Model | SM321A |
MEDIA CONVERTER & MODULE | |
Standards & Protocols | IEEE 802.3z, TCP/IP |
Wavelength | TX: 1550 nm RX: 1310 nm |
Dimensions (L x W x H) | 2.2*0.6*0.5 in (55.4*14.6*12.9 mm) |
Diet | 3.3V |
Safety & Emissions | FCC, CE |
Cable | Single-Mode Fiber |
Fiber type | 9/125 μm Single-Mode |
Max. cable length | 20 KM |
Data transmission speed | 1.25 Gbps |
Door type | LC Duplex |
Hardware Features | DDM SFP-MSA Hot Swappable |
Package Content | SM321A Installation Guide |
Environment | Operating Temperature: 0°C to 70°C (32°F to 158°F) Storage Temperature: -40°C to 85°C (-40°F to 185°F) Operating Humidity: 10–90% RH, Non-Condensing Storage Humidity: 5–90% RH, Non-Condensing |