Shorter run, same single-fibre trick. If your two sites are closer — say a campus hop or a neighbouring office — you don't need the 20 km module. You need this one.
The TL-SM321A-2 is a 1000Base-BX WDM bi-directional SFP rated to 2 km on 9/125 μm SMF. It transmits at 1550 nm and receives at 1310 nm, so it pairs with the matching wavelength module at the other end. LC Simplex port, 1.25 Gbps data rate, DDM built in for real-time power monitoring.
Hot-swappable, FCC and CE certified, runs from 0 to 70 °C. Drop it in, verify the link light, close the lid. Twenty are sitting on the shelf. Add to cart and it's moving
| brand | TP-LINK |
| model | TL-SM321A-2 |
| type | 1000Base-BX WDM Bi-Directional SFP Module |
| max_transmission_distance | 2 km |
| fibre_type | 9/125 μm Single-Mode Fiber |
| wavelength_tx | 1550 nm |
| wavelength_rx | 1310 nm |
| data_rate | 1.25 Gbps |
| port_type | LC Simplex |
| power_supply | 3.3 V |
| standards | IEEE 802.3z, TCP/IP, SFP-MSA |
| ddm_support | 1 |
| hot_swappable | 1 |
| certifications | FCC, CE |
| operating_temperature | 0–70 °C |
| storage_temperature | -40 to 85 °C |
| operating_humidity | 10–90% RH, non-condensing |
| storage_humidity | 5–90% RH, non-condensing |
| category | TECHNOLOGY > NETWORKING |
