Which port should I connect my fiber optic router to

Fiber optic cables from your ISP should connect to an Optical Network Terminal (ONT), which then links to your router's WAN port or SFP/SFP+ port if supported.

In most residential fiber installations, the fiber optic cable does not connect directly to the router. Instead, it terminates at an Optical Network Terminal (ONT) provided by your ISP. The ONT converts the optical signal into an electrical Ethernet signal that your router can use . After this conversion, you connect the ONT to your router using a standard Ethernet cable, plugging it into the router's WAN port, which is often labeled “Internet” or colored differently from LAN ports .

Some advanced routers have SFP or SFP+ ports that allow direct fiber connections. In this case:

• Insert the appropriate SFP/SFP+ module into the router's SFP port.
• Connect the fiber cable to the module.
• Configure the SFP interface as the WAN port in the router's settings to ensure proper internet access .

This setup is common in high-speed or enterprise-grade networks where the ONT may be replaced by a compatible SFP module provided or verified by the ISP .

• Port labeling: Look for ports labeled WAN, Internet, Fiber, FTTH, or PON.
• Cable type: Ensure the fiber cable matches the router or SFP module type (single-mode or multi-mode, SC/APC, LC, etc.), .
• Power sequence: Power on the ONT first, then the router, to allow proper signal initialization .
• Environmental factors: Place both ONT and router in a dry, ventilated area near power outlets .

By following this approach, your fiber connection will be properly converted and routed, ensuring optimal internet performance.