The device that serves as your ISPs endpoint of the passive optical network (PON). The OLT also provides the interface between a PON and your ISP’s core network. Simply put, an OLT is ISP equipment.
The OLT is the device that exists at your ISPs central hub.
An OLT has a few purposes:
The upstream channel transmits different types of data and voice traffic from users to the ISP. The downstream channel is what receives data, voice and video traffic and sends it to all ONT devices on your network.