Structure of FTTX

And then there's the article, Leitone Technologies, about the architecture of FTTX today.
As can be seen from the figure in the previous article, FTTH is all connected to the terminal by an optical fiber network, and the terminal connected to this is called an optical network terminal(ONT). FTTB or FTTC is connected to a building or a roadside through a fiber optic network, and then through a copper twisted pair network or wireless connection to the terminal. The terminal device of the fiber optic network is called a optical network unit(ONU). From the ONU through the copper twisted pair network or wireless connection to the network terminal(NT). FTTCab is similar to FTTC, except that its ONU is located in the telecommunications transfer box(Cabinet). The FTTB, FTTC, and FTTCab in the figure all belong to the "partial" fiber to the home, which means that instead of the fiber directly connecting to the end user, it reaches the end user and then connects to the end user through the twisted pair network. In FTTCab, the ONU in the telecommunications transfer box is usually 1000 to 2000 m from the end user, in which case an ONU unit can support about 500 end users. In FTTC, ONU is closer to the end user, 200-1000m, and can support 8 to 32 end users. The network between OLT and ONT/ONU is called the optical distribution network ODN and its distance can reach 20km, as shown in the figure