1.25 Gb/s BiDi SFP Transceiver 20 km for ISP / Enterprise Networks

The Teltonika PR4LC21K is a BiDi SFP transceiver pair designed for single-fiber point-to-point optical links spanning up to 20 km over G.652 single-mode fiber. The solution is deployed in enterprise and ISP networks where inter-node connectivity is established over a single optical strand, eliminating the need for duplex fiber runs between sites. BiDi SFP modules are a standard choice for inter-building links, traffic aggregation, and backhaul segments in distributed network architectures.

Each adapter delivers 1.25 Gb/s over single-mode fiber with a maximum power draw below 0.8 W. The BiDi design uses wavelength-division multiplexing on a single fiber strand: adapter 1 transmits at 1310 nm and receives at 1550 nm, while adapter 2 operates in reverse. The fully metallic enclosure provides low EMI emissions and robust ESD protection. An operating temperature range of -40°C to +85°C supports deployment in uncontrolled technical environments, outdoor enclosures, and industrial facilities.

PR4LC21K is supplied as a matched functional pair with Simplex LC connectors, compatible with SFP slots on Teltonika routers and switches as well as third-party equipment supporting the SFP standard. Both adapters must be used together on the same optical link, ensuring full interoperability in point-to-point topologies. RoHS and REACH compliance qualifies the pair for projects subject to environmental regulatory requirements.

The solution targets network integrators, ISP operators, and enterprise IT teams deploying or extending fiber optic infrastructure over medium distances. Typical use cases include campus inter-building links, metropolitan backhaul segments, and uplinks between distribution and core switching layers where single-fiber connectivity reduces both installation costs and ongoing infrastructure overhead.