Specifies the physical medium characteristics for twisted pair multipoint interconnections in either 2-wire or 4-wire network topology, a binary and bi-directional signal transfer, the electrical and mechanical design of the endpoint system branch cables and the common trunk cable which may be up to 1200 m in length, the component measurements of the integrated type generators and receivers within the endpoint system, the applicable data signalling rate up to 12,5 Mbit/s.