Fiber optic cables usually connect to an ONT first, and the router should use its WAN port or an SFP port if it supports direct fiber input.

Using an ONT

Most residential fiber setups require an Optical Network Terminal (ONT) provided by your ISP. The fiber optic cable from the wall outlet plugs into the ONT's fiber input port, which converts the optical signal into an electrical signal compatible with standard networking equipment . From the ONT, you then use a high-quality Ethernet cable (Cat6 or higher) to connect to your router's WAN port, which is typically labeled and often colored differently from LAN ports . This setup ensures reliable high-speed performance and protects the fiber connection from damage.

Direct Fiber Connection

Some modern routers are fiber-ready and include an SFP (Small Form-factor Pluggable) port. If your router has an SFP port, you can connect the fiber optic cable directly using a compatible SFP module . This bypasses the ONT, but only routers specifically designed for fiber input support this method. Check your router's specifications for terms like “fiber-ready”, “GPON”, or SFP compatibility.

Key Considerations

• Port Type: Use the WAN port for Ethernet from an ONT, or an SFP port for direct fiber.
• Cable Quality: Use Cat6a or higher for Ethernet connections to maintain multi-gigabit speeds .
• Router Placement: Keep the router near the ONT to minimize cable length and potential signal loss .
• Configuration: After connecting, power on the ONT first, then the router, and configure the router with ISP credentials if required . In summary, for most home fiber installations, the WAN port on your router is the best choice when connecting via an ONT. If your router supports an SFP port, you can connect the fiber directly, but this is less common in standard residential setups.