Optical line termination

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Optical line termination" – news · newspapers · books · scholar · JSTOR (March 2024) (Learn how and when to remove this message)

An optical line termination (OLT), also called an optical line terminal, is a device which serves as the service provider endpoint of a passive optical network. It provides two main functions:

1. to perform conversion between the electrical signals used by the service provider's equipment and the fiber optic signals used by the passive optical network.
2. to coordinate the multiplexing between the conversion devices on the other end of that network (called either optical network terminals or optical network units).

An OLT can have several ports, and each port can drive a single PON network with split ratios or splitting factors of around 1:32 or 1:64, meaning that for each port on the OLT, up to 32 or 64 ONUs at customer sites can be connected although this depends on the PON standard the OLT and the PON network supports.^[1] XGS-PON networks support split ratios of up to 1:128. An OLT with 272 ports can support up to 34,816 users assuming a split ratio of 1:128 for every port.^[2][3]

The diagram below depicts an OLT within a fiber-optic network.