1. Power on the ONT and Modem/Router




2. Connect LAN1 port of ONT to WAN port (red port) of D-Link DSL-3890 Modem


(Usually, it's LAN1 but you could try other ports if the light is always off)





3. Connect Router to your computer




4. Open the browser and go to and login


(The credential is on the back of the router)





5. After login, go to Settings --> Internet





6. Follow the screenshot to change the settings 





7. The Internet should be on now.