TP-Link SM321B Bi-Directional WDM SFP is a module 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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SM321B | 1000BASE-BX10-D LC Bidirectional Mini-GBIC SFP Module

The TP-Link SM321B Bi-Directional WDM SFP Module is designed for 1000BASE-BX Gigabit Ethernet 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 1550 nm / Rx 1310 nm wavelength. It integrates the DDM (Digital Diagnostic Monitoring) function for real-time monitoring of operating parameters and offers a hot-pluggable design, which allows for 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
- Hot-Pluggable design for maximum flexibility
Further details
Technical data sheet
| Model | SM321B |
| MEDIA CONVERTER & MODULE | |
| Standards & Protocols | IEEE 802.3z, TCP/IP |
| Wavelength | TX: 1310 nm RX: 1550 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 | SM321B 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 |


