Network transceiver module MikroTik S-31DLC20D SFP 1250 Mbit/s 1310 nm LC

MikroTik S-31DLC20D SFP 1250 Mbit/s 1310 nm LC is a compact fiber optic transceiver module designed for single-mode links. The module supports 1.25 Gbit/s (1250 Mbit/s) data rate over single-mode fiber at a 1310 nm wavelength and uses LC connectors. It is intended to extend fiber connectivity in compatible MikroTik switches and routers and is suitable for long-distance links when installed in devices that accept SFP form-factor transceivers.

Advantages

The S-31DLC20D combines a standard SFP interface with 1310 nm single-mode optics to provide reliable gigabit-class fiber connectivity. It supports diagnostic monitoring (DDM) for real-time status of optical parameters and is tested for compatibility with a range of MikroTik devices. Its LC connector and single-mode optics enable longer reach compared with multimode modules, making it appropriate for backbone links or point-to-point connections up to 20 km over single-mode fiber.

Suitable for

• Point-to-point single-mode fiber links up to 20 km
• Upgrading or extending fiber ports on compatible MikroTik switches and routers
• Replacing or adding SFP transceivers in networking equipment that accepts standard SFP modules
• Backbone or aggregation links within campus or ISP networks

Key specifications

• Form factor: SFP (small form-factor pluggable)
• Data rate: 1250 Mbit/s (1.25 Gbit/s)
• Wavelength: 1310 nm
• Fiber type: single-mode fiber (SMF)
• Connector type: LC duplex
• Maximum link distance: up to 20 km (single-mode, typical conditions)
• Diagnostics: Digital Diagnostic Monitoring (DDM) supported

How to use

Insert the SFP module into an empty SFP slot on a compatible switch or router while the host device is powered on or according to the device manufacturer’s hot-plug guidance. Connect a duplex LC single-mode fiber patch cable to the module’s LC connector, ensuring correct transmit/receive orientation. Verify link status and speed in the host device’s interface or management software. Use diagnostic monitoring to check optical power, temperature, and other parameters if supported by the host.

Usage recommendations

Use clean LC connectors and follow standard fiber handling procedures to avoid contamination and signal loss. Confirm device compatibility and firmware support for SFP modules in the host equipment. For reliable long-distance links, use single-mode fiber rated for the desired distance and test the link after installation. Store unused modules in protective packaging to prevent dust ingress.