Inspect the gateway (router/modem) itself to find these features or plug in the model number online and dig up the original specs. The ONT is linked to your router or gateway using an Ethernet cable. The technician powers, tests, and activates the connection to confirm full speed and signal quality. Compatible router: Verify that your router supports fiber optic input (look for an SFP or WAN port labeled. Connect the fiber optic cable from your ISP to the ONT (Optical Network Terminal) provided. Before diving into the connection process, gather these critical components: Optical Network Terminal (ONT): The cornerstone of most fiber setups, typically provided by your ISP. This. I know that "show cable-diag tdr int [slot/port]" command can check 10/100/1000 etherent link.