TP-Link TL-FC111B-20 10/100 Mbps Fiber Media Converter

The TP-Link TL-FC111B-20 performs 100BASE-FX to 100BASE-TX media conversion using WDM (Wavelength Division Multiplexing) over single-mode fiber, with a working range of up to 20 km. The critical distinction between this and a standard media converter is the single-fiber architecture: by transmitting at 1310 nm and receiving at 1550 nm simultaneously on one strand, it eliminates the second fiber entirely. In a dual-fiber deployment, every run requires two physical fiber cores — the TL-FC111B-20 halves that requirement, which translates directly to lower cable and conduit costs on any run longer than a few hundred meters. The RJ45 port handles 10/100 Mbps with auto-negotiation and auto MDI/MDIX, making the copper-side installation straightforward regardless of cable type or switch port configuration.

This converter is built for network engineers extending connectivity between buildings, across campuses, or into industrial facilities where pulling new copper is impractical and running two fiber strands is unnecessarily expensive. It is an unmanaged, fixed-configuration device — there is no web interface, no SNMP agent, and no link fault pass-through control, which keeps deployment simple but limits visibility in monitored networks. The companion unit (TL-FC111A-20) is mandatory at the far end; the asymmetric wavelength design means it cannot interoperate with non-paired WDM converters. For any organization that needs to push Fast Ethernet beyond copper's 100-meter limit on a constrained budget and with minimal configuration overhead, this converter delivers precisely what it promises.