Fgtech Store on Instagram: "ONU vs ONT - What Your ISP Never Explains ONU and ONT are often used as the same thing, but they are slightly different. ONU means Optical Network Unit. It is a general term used in fiber networks. ONT means Optical Network Terminal. It is the customer side version of an ONU, usually installed in homes or offices. Function wise, both ONU and ONT do the same job. They receive fiber signals from your ISP and convert them into usable internet. Simple way to remember: ONU