Fibre Distribution Terminal (FDT)
A fibre distribution terminal, also called a fibre distribution hub, is the cabinet or enclosure where large feeder cables from the exchange are broken out into smaller distribution cables, usually through first-level optical splitters.
What is Fibre Distribution Terminal (FDT)?
The FDT is the first point of flexibility in an FTTH network. It sits between the feeder network, which comes from the central office, and the distribution network, which runs towards customers. It provides termination points, splitter trays and cross-connect patching so that fibres can be rearranged as customers join. Each FDT serves a defined area, its "FDT boundary". Ideally it sits near the middle of that area, although the location of existing ducts and the need for permits often decide where it actually goes.
How it works
Feeder fibres enter the FDT and are either connected to the inputs of level-1 splitters or passed straight through to distribution fibres. Splitter outputs are patched or spliced to distribution cables that lead to FATs. Outdoor FDTs are street cabinets and are the most common type. Indoor FDTs are used in large buildings (for example, those with more than about 128 homes) and sit in a telecoms room.