Mikrotik S-3553LC20D network transceiver module 1250 Mbit/s SFP

The Mikrotik S-3553LC20D network transceiver module is a pair of compatible 1.25 Gbps SFP optical modules designed for single-mode fiber links up to 20 km. It comprises two complementary transceivers: S-35LC20D operating at T1310nm/R1550nm and S-53LC20D operating at T1550nm/R1310nm, both using LC connectors and supporting Digital Diagnostic Monitoring (DDM). The module family uses a standard SFP interface and provides a straightforward way to extend fiber connections while maintaining compatibility with many MikroTik devices and other vendors' SFP ports.

Advantages

The S-3553LC20D offers reliable 1.25 Gbit/s optical transmission over single-mode fiber with support for links up to 20 km and integrated DDM for real-time monitoring of optical parameters. Its LC connector and standard SFP form factor ensure wide compatibility with MikroTik switches and routers as well as third-party SFP-capable equipment. Units are tested for interoperability with a range of MikroTik models, simplifying deployment in mixed-vendor environments.

Suitable for

• Extending Ethernet networks over single-mode fiber up to 20 km
• Interconnecting switches and routers with SFP slots
• Replacing or adding SFP optical ports in MikroTik rack and desktop devices
• Use in mixed-vendor infrastructures requiring standard SFP optical transceivers

Key specifications

• Interface type: SFP (Small Form-factor Pluggable)
• Data rate: 1.25 Gbit/s (1250 Mbit/s)
• Fiber type: Single-mode fiber (SMF)
• Maximum link distance: up to 20 km (depending on fiber and link budget)
• Optical wavelengths: S-35LC20D T1310nm / R1550nm; S-53LC20D T1550nm / R1310nm
• Connector type: LC duplex
• Monitoring: Digital Diagnostic Monitoring (DDM) supported

How to use

Insert each SFP transceiver firmly into the SFP slot of the compatible network device while the device is powered down or following the manufacturer's hot-swap guidance. Connect LC-terminated single-mode fiber patch cords to the corresponding transmit and receive ports according to the wavelength pairing. Verify link status on the host device and enable or configure optical port settings if required by the router or switch management interface. Monitor DDM parameters via the device interface where supported to check optical power, temperature, and other diagnostics.

Usage recommendations

For reliable operation, use quality single-mode fiber with appropriate attenuation characteristics and ensure connectors are clean before mating. Confirm compatibility and firmware behavior on the target MikroTik model or third-party equipment, and test link performance over the intended distance. Avoid bending fiber beyond recommended radii and protect transceivers from electrostatic discharge during handling.