The Allied Telesis AT-MC101XL-20 is a Fast Ethernet media converter that bridges 100Base-TX copper networks with 100Base-FX multimode fiber infrastructures. It extends network reach beyond standard copper limitations, enabling data transmission over distances up to 2 km on fiber while maintaining full IEEE 802.3u compliance. The converter operates in both half- and full-duplex modes and passes IEEE 802.1Q VLAN packets without modification.
Technical Specifications
Ports & Connectivity
• 1 × 100Base-TX (RJ-45) UTP, Category 5 — copper side, 100 m maximum
• 1 × 100Base-FX (ST Duplex) multimode fiber — 2 km maximum distance
Optical Parameters
• Wavelength: 1310 nm
• Multimode fiber (MMF) over ST duplex connectors
Power Requirements
• External 12V DC, 500 mA power supply unit
• Compatible with AT-MCR12 chassis for centralized power distribution
Environmental
• Operating temperature: 0 to 40 °C
• Storage temperature: −20 to 80 °C
Physical
• Dimensions: 10.5 × 9.5 × 2.5 cm
• Weight: 294 g
– Key Features
• Auto MDI/MDI-X eliminates crossover cable requirements
• MissingLink™ detection identifies fiber breaks and connectivity faults
• Link Test diagnostic function for continuous network verification
• Transparent to IEEE 802.1Q packets — VLAN-aware operation
• RoHS compliant manufacturing
• Comprehensive status indicators: Power, dual Link, dual Activity, Full-Duplex, and MissingLink™ LEDs
– Typical Applications
Network extension across campus or building backbones. Long-distance Ethernet connectivity where fiber infrastructure exists. Equipment isolation in electromagnetically noisy industrial environments. Backwards compatibility with legacy Fast Ethernet copper segments requiring fiber extension.
– Compatibility & Integration
Deploys as a standalone unit with external power adapter or mounts within AT-MCR12, AT-TRAY4, or AT-TRAY1 chassis for rack environments. Wall-mounting available with AT-WLMT bracket. IEEE 802.3u and 802.1Q certified.

















