The WAN port links your router to the internet or another wide area network. It keeps local traffic inside your network and sends outbound traffic to the WAN only when needed. To connect your fiber optic cable to a router, ensure you have the following: Fiber optic modem (ONT): Most fiber connections require an Optical Network Terminal (ONT), provided by your ISP. These can behave like a typical Ethernet switch. This. The Ethernet port is relative to the optical port, which refers to the physical characteristics of the fire extinguisher, mainly refers to the copper cable, and is the processed electrical signal. At present, the commonly used network interfaces include 100-megabit port and gigabit port.