What is OLT GPON ONU in Optical Fiber Network

Published: August 20, 2022

Last Modified: March 26, 2023

What is OLT GPON ONU in Optical Fiber Network

EPON OLT Fiber Network Configuration

OLT, GPON, EPON, ONU, and ONT are all equipment used in an optical fiber network to provide the maximum and highest data transmission speed while minimizing network costs. The OLT device is used at the start point of the centralizing office node and the ONU is used at the last endpoint to terminate the line. Between OLT and ONU fiber, splitters and other passive network devices are used to distribute fiber networks. The GEPON OLT Configuration for Fiber Networks is very easy to understand if you follow a proper network diagram. Also, know how to protect your network product from light.

OLT (Optical Line Termination )

The OLT is also called the Optical Line Terminal. An OLT is an endpoint of the passive optical network (PON).

The OLT is also called the Optical Line Terminal. An OLT is a passive optical network (PON) endpoint.

OLT’s main function is to convert electrical signals used by service provider equipment and fiber optical signals used by the passive optical network (PON), enabling its co-ordinate multiplexing between end-user devices ONU (Optical Network Units) or ONT (Optical Network Terminals ).

The OLT installed service provider and client equipment use ONU or ONT for endpoint service provision. In layman’s terms, it begins with OLT and ends with ONU or ONT at the customer’s end.


PON, full form, is Passive Optical Network. It’s used for point-to-multipoint networks with fiber optics to reduce the cost of the fiber network.

PON standard:



1. GPON (Gigabit Passive Optical Network)

GPON is a new generation of broadband (BPON)over passive network access. GPON provides a high bandwidth speed of up to 2.5Gbit/s. The protocols used by GPON are ATM, GEM, and Ethernet.

2. EPON (Ethernet Point-to-Point Network)

The full form of EPON is Ethernet Passive optical network. EPON is an IEEE standard that uses Ethernet to send the data packet. EPON and GEPON are fast Ethernet over fiber networks with up to 1.25 Gbit/s of download and upload data streams.


ONU’s full form is an optical network unit and ONT Full form is an optical network unit. The Passive Optical Network consists of a centralized office node called OLT (Optical Line Terminal) and endpoint customer site equipment called ONU and ONT. Fiber and a splitter are used to distribute the fiber network between the OLT and the ONU.

While internet plan speed increases, fiber takes over all the LAN and wireless networks. LAN and wireless networks have a limitation on delivering speed to long distances, where fiber can easily provide a high-speed internet plan up to 10 Gbps with the latest OLT technology.

The EPON OLT network was the first to be upgraded to GPON OLT network and Gigabit ONT device for last-mile connectivity fiber network can easily provide an internet connection up to 20 KM or more, depending on the fiber network and device supported capacity.

The connection method and configuration are based on Fiber technology, regardless of whether you are using DBC OLT, VSOL GPON Olt, Sysrotech OLT device, or Huawei OLT device. 

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