By contrast, PONs use one router/switch port and a single fiber between router/switch and the passive splitter to serve multiple subscribers, sharing the capacity of the wavelength. This network is suitable for building. A passive optical network (PON) uses fiber-optic technology to deliver data from a single source to multiple endpoints. In this use, a PON. The ONU, a key device in a PON (Passive Optical Network), converts optical signals into electrical ones for users. It comes with various ports to suit different needs. This article uses the FS ONU TA1910-4GVC-W as an example to explain these ports and their connections in detail. In this guide, we'll break down.