This Recommendation provides the management information model of the Q3-interface in a TMN [8] for the management of the D-channels in an ISDN switch. In particular, it focuses on the fault and performance management of the data link and network layer of ISDN D-channels. Managed objects are specified by using the OSI-management templates of Recommendation X.722 [5]. These specifications are based on the prosaic description of the D-channel management aspects as provided by Recommendation M.3640.