How to distinguish between optical access network OLT, industrial ONU, ODN and ONT?

Optical access network is an access network that uses light as the transmission medium, instead of copper wire, used to access every family. Optical access network. Optical access network generally consists of three parts: optical line terminal OLT, optical network unit industrial-grade ONU, optical distribution network ODN, among which OLT and ONU are the core components of optical access network.

What is OLT?

The full name of OLT is Optical Line Terminal, optical line terminal. The OLT is an optical line terminal and a central office equipment of telecommunications. It is used to connect optical fiber trunk lines. It functions as a switch or router in a traditional communication network. It is a device at the entrance and exit of the external network and the internal network. Placed at the central office, the most important executive functions are traffic scheduling, buffer control, and provision of user-oriented passive optical network interfaces and bandwidth allocation. To put it simply, it is to achieve two functions. For the upstream, it completes the upstream access of the PON network; for the downstream, the acquired data is sent and distributed to all ONU user terminal devices through the ODN network.

What is an industrial ONU?

The industrial-grade ONU is the Optical Network Unit. The industrial-grade ONU has two functions: it selectively receives the broadcast sent by the OLT, and responds to the OLT if the data needs to be received; collects and buffers the Ethernet data that the user needs to send, and sends it to the network according to the assigned sending window. The OLT sends the buffered data.

Different deployment of ONU access methods in FTTx networks are different, such as FTTC (Fiber To The Curb): industrial-grade ONU is placed in the central computer room of the community; FTTB (Fiber To The Building): industrial-grade ONU is placed in the junction box of the corridor ; FTTH (Fiber To The Home): ONU is placed in home users.

What is ONT?

ONT is the Optical Network Terminal, the most terminal unit of FTTH, commonly known as "optical modem", similar to the xDSL electric modem. ONT is an optical network terminal and is applied to end users, while ONU refers to an optical network unit, and there may be other networks between it and the end user. ONT is an integral part of ONU.

What is the relationship between industrial ONU and OLT?

The OLT is the management terminal, and the ONU is the terminal; the service activation of the industrial-grade ONU is issued through the OLT, and the two are in a master-slave relationship. Multiple ONUs can be connected to one OLT through the splitter.

What is ODN?

ODN is the Optical Distribution Network, optical distribution network, is the optical transmission physical channel between OLT and ONU, the main function is to complete the two-way transmission of optical signals, usually by optical fiber cables, optical connectors, optical splitters and installation to connect these The components of the supporting equipment of the device, the most important component is the optical splitter.