MikroTik S-31DLC20D SFP Transceiver

The MikroTik S-31DLC20D is a 1.25 Gbps SFP transceiver module designed for extended-reach fiber connections. This single-mode optical module delivers reliable data transmission up to 20 kilometers using 1310nm wavelength technology. It provides cost-effective long-distance connectivity for enterprise networks, ISP infrastructure, and campus backbone deployments.

Technical Specifications

Optical Characteristics

• Wavelength: 1310nm (Tx)
• Data Rate: 1.25 Gbps
• Maximum Distance: 20 kilometers over OS1/OS2 single-mode fiber
• Fiber Type: Single-mode (SMF) – 9/125μm
• Connector: Dual LC (duplex)
• Standard: 1000BASE-LX compatible

Electrical & Performance

• Interface: SFP (Small Form-factor Pluggable)
• Encoding: 8B/10B
• Digital Diagnostics: DDM/DDMI support (SFF-8472 compliant)
• Link Budget: Approximately 13 dB
• Transmit Power: Typical optical output specifications
• Receiver Sensitivity: Standards-compliant for 20km operation

Environmental & Physical

• Operating Temperature: -40°C to +70°C (extended range)
• Storage Temperature: -40°C to +85°C
• Power Consumption: Low power consumption typical for 1.25G SFPs
• Form Factor: Standard MSA-compliant SFP module
• Weight: Approximately 20-30 grams

Compatibility

• Tested MikroTik Models: RB260GS, RB2011LS, RB2011LS-IN, RB2011UAS-IN, RB2011UAS-RM, RB2011UAS-2HnD, RB2011UAS-2HnD-IN, CCR1036-12G-4S, CCR1016-12G
• Third-Party Compatibility: Works with standard SFP-compatible switches, routers, and media converters

Use Cases & Applications

Campus Network Connectivity

The S-31DLC20D enables fiber connections between buildings across university campuses or corporate parks. IT teams can link distant facilities up to 20km apart with reliable Gigabit speeds. Additionally, the extended temperature range supports outdoor fiber installations in climate-controlled enclosures.

ISP Infrastructure

Service providers use these modules for point-to-point links between distribution nodes and customer premises. The DDM functionality helps network operations centers monitor link health remotely. Furthermore, compatibility with non-MikroTik equipment protects existing infrastructure investments.

Enterprise WAN Extension

Organizations extend their networks between office locations without leasing expensive carrier circuits. The module connects remote sites directly through dedicated fiber runs. However, distances beyond 20km require alternative solutions like 1000BASE-EX modules rated for 40km.

Data Center Interconnects

Data centers leverage these transceivers for short-haul connections between facilities within metropolitan areas. The single-mode fiber provides future-proof infrastructure capable of upgrades to higher speeds. For instance, the same fiber plant can later support 10G transceivers.

Additional Resources: View the complete MikroTik SFP module lineup and fiber optic standards documentation for deployment planning assistance.

Compatibility Note: Always verify SFP compatibility with specific equipment models before deployment. While the S-31DLC20D follows MSA standards, some proprietary systems may require vendor-specific modules. The DDM feature requires host equipment with digital diagnostic monitoring support to display real-time optical metrics.