Method for determining the electrical cable length of an active ring of a token ring local area network

A method and apparatus which measures the electrical cable length of a ring in an active Token-Ring local area network. The system determines the data transmission speed of the ring, the type of cable being used to connect the stations of the ring, the manufacturer of the circuitry used in the active monitor station, and the number of standby monitors actively connected to the ring. The system determines the time between two successive tokens having no intervening non-token frames, and then subtracts the amount of delay through the active monitor station and the amount of delay through each of the standby monitor stations. It then multiplies this result by the speed of light and by a velocity constant determined by the type of cable being used, to produce the total cable length between all active stations on the ring.