Commercial and multiple dwelling unit (MDU) projects often feature a main distribution frame (MDF) that interconnects and manages the telecommunications wiring between itself and remotely located intermediate distribution frames (IDFs). The MDF typically connects external public lines coming into the building with the internal private lines that feed back from the IDFs.
In practice, the MDF is typically centrally located near the demarcation point, whereas the IDFs are located on each floor, wing or unit within the building.
Fiber optic cabling and fiber-ready enclosures, including rack trays and wall-boxes, are often used for MDF and IDF wiring because they support long cable distances and very fast network speeds. Fiber-based systems easily exceed the distance limitation of twisted pair-based systems (100m / 330ft.), and they easily support network speeds exceeding 10Gbps. It’s also common to see multi-strand fiber optic cabling, such as 6 strand and 12 strand, connecting the MDF to the IDFs to accommodate signal distribution to individual rooms and/or devices.