The composition of PON network: the three main parts of PON (passive optical network) include OLT (Optical Line Terminal), terminal ONU (Optical Network Unit), and ODN (Optical Distribution Network).

Introduce the main parts of these three PON. 
01. 
Optical Line Terminal (OLT). 
OLT equipment is a kind of important office-end equipment, which can be connected with the front-end (convergence layer) switch with a network cable, converted into optical signals, and interconnected with the splitter of the user side with a single optical fiber; realize the control, management and distance measurement of the user end equipment ONU; and like the ONU equipment, it is an integrated optoelectronic equipment. 

02. 
Optical network unit (ONU). 
ONU equipment, generally equipped with optical receiver, uplink optical transmitter, multiple bridge amplifier network monitoring equipment is called ONU. 
At ordinary times, the ONU in the optical fiber communication industry refers to the optical cat, which is located at the user end. 

03. 
Optical distribution network (ODN). 
ODN is a FTTH optical cable network based on PON equipment. 
Its function is to provide an optical transmission channel between OLT and ONU. 
ODN includes the equipment needed for transmission, such as splitter, optical cross box, distribution frame and so on. In PON network, the construction cost of PON is mostly used on ODN, long distance and large number of optical fibers, a large number of optical boxes, splitters and labor costs, each of which is expensive.