Apparatus and method for determining operational mode for a station entering a network

A station in a communications network determines the mode (full-duplex or half-duplex) in which it communicates with a concentrator port by establishing a Registration routine between the station and the concentrator port. The station and concentrator port exchange frames which disclose the capabilities of the concentrator port. If the concentrator port has duplex capabilities, the station enters as a duplex station. Otherwise, the station enters in a half-duplex (token ring) mode.