MikroTik S-31DLC20D 1.25G SFP Single Mode Transceiver for Enterprise Networks

S-31DLC20D is a 1.25G single-mode SFP transceiver for optical connections of up to 20 kilometers, designed for long-distance Gigabit links between geographically separated locations where single-mode fiber infrastructure is already in place. It is widely used in ISP networks, metropolitan infrastructures, and connections between distant buildings or network nodes where stable optical connectivity over long distances is an essential requirement.

The transceiver operates at 1310nm wavelength with a Dual LC UPC connector and supports 1.25G data rates, covering Gigabit connectivity needs over single-mode fiber up to 20 kilometers. DDM (Digital Diagnostic Monitoring) support enables real-time monitoring of transmit and receive optical power, temperature, and supply voltage directly from the management interface — critical for rapid diagnostics of long-distance links. The -40°C to +70°C operating range ensures reliability in both outdoor and indoor installations.

S-31DLC20D is tested and compatible with a wide range of MikroTik equipment featuring SFP 1G slots, including the RB260GS, RB2011 series, and CCR1036-12G-4S, as well as SFP devices from other manufacturers. An MTBF of 100,000 hours confirms reliability for permanent installations in production infrastructures. It installs directly into any standard SFP slot without additional configuration, using standard LC connectors on single-mode fiber.

Recommended for ISPs and integrators building or expanding metropolitan optical networks, for point-to-point connections between distant locations over existing single-mode fiber, and for any scenario where a single 1310nm single-mode SFP module covers the required operational distance. The right choice as an individual module for infrastructures where a complementary wavelength transceiver pair is already available or where dual-fiber connectivity is used.