Metallic path facilities (MPF) consist of unshielded twisted pairs of copper wires that form the physical circuit connecting a customer's premises to the main distribution frame at a local telephone exchange. In this variant, both broadband and voice (baseband) services, together potentially with a video on demand service, are provided. Metallic Path Facility or 'MPF' means a circuit comprising a pair of twisted metal wires between a Customer's premises and a main distribution frame in a local access node that employs electric, magnetic, electro-magnetic, electro-chemical or electro-mechanical energy to convey Signals when. This specification defines the electrical parameters of the Metallic Path Facility (MPF) provided by BT. There are potentially 4 types of MPF: This specification defines the electrical parameters for all 4 types, excluding any aspects of splitter specification. The specification applies to the.