Network Transceiver Module Mikrotik S-3553LC20D 1250 Mbit/s SFP

The S-35/53LC20D set includes two SFP optical transceivers for single-mode fiber links. The S-35LC20D operates at 1310 nm transmit / 1550 nm receive and the S-53LC20D operates at 1550 nm transmit / 1310 nm receive. Both modules support 1.25 Gbit/s data rate, use LC connectors, include DDM support for monitoring, and are specified for single-mode fiber reaches up to 20 km.

Advantages

These SFP transceivers provide bidirectional single-fiber operation using complementary wavelengths, offer digital diagnostics monitoring (DDM) for link status and diagnostics, and maintain compatibility with a wide range of devices that accept standard 1.25 G SFP modules. The LC connector and single-mode design allow long-reach connections up to 20 km while keeping a compact SFP form factor.

Suitable for

• Point-to-point fiber links between switches or routers
• Extending network segments over single-mode fiber up to 20 km
• Fiber uplinks in small and medium office networks

Key specifications

• Form factor: SFP (small form-factor pluggable)
• Data rate: 1.25 Gbit/s
• Fiber type: Single-mode
• Connector: LC
• Wavelengths: pair with 1310 nm Tx / 1550 nm Rx and 1550 nm Tx / 1310 nm Rx
• Maximum link distance: up to 20 km (single-mode)
• Monitoring: Digital Diagnostic Monitoring (DDM)

How to use

Insert each SFP module into the SFP slot of compatible network equipment until it seats firmly. Connect the single-mode LC fiber jumper between the two modules, ensuring correct mating of the LC connectors. The pair must be used in complementary orientation (one module with 1310 nm transmit paired to the module with 1310 nm receive) to establish a bidirectional link. Allow the devices to negotiate link parameters at 1.25 Gbit/s and verify link status via the host device or DDM readings.

Recommendations

Use high-quality single-mode LC fiber cabling and keep fiber connectors clean. Verify compatibility with the host device and confirm that the equipment supports 1.25 G SFP modules and DDM if monitoring is required. Avoid exceeding the specified 20 km distance to maintain reliable optical performance.