Q. Explain the Importance of distributing frames?

Basically four levels of cabling are used as displayed in Figure. At the subscriber end, drop wires are taken to a distribution point. Drop wires are the individual pairs which run into the subscriber premises. At distribution point, drop wires are connected to wire pairs in distribution cables. A number of distribution cables from nearby geographical locations are terminated on a feeder point where they are linked to branch feeder cables which, in turn, are connected to main feeder cable. The major feeder cables carry a larger number of wire pairs, specifically 100-2000,than distribution cables which carry approximately 10-500 pairs. Feeder cables are terminated on a main distribution frame (MDF) at the exchange. Subscriber cable pairs emanating from the exchange are also terminated on MDF.