Optical Line Termination — OLT
Optical Network Terminatior — ONT
OLT and ONT? Lets start with OLT then. The main function of OLT is to control the information float across the ODN, going both directions, while being located in a central office. Maximum distance supported for transmitting across the ODN is 20 km. OLT has two float directions: upstream (getting an distributing different type of data and voice traffic from users) and downstream (getting data, voice and video traffic from metro network or from a long-haul network and send it to all ONT modules on the ODN.
Em uma conexão óptica de longa distância, baseada em tecnologia GPON, o equipamento de rede ONT fica na instalação de usuário e se comunica com o equipamento de terminação de linha óptica(OLT).
http://www.ad-net.com.tw/introduction-to-olt-optical-line-terminal-and-ont-optical-network-terminal-onu-optical-network-unit/