Abstract: The implementation of BRI/ISDN services is changing the way services can be maintained with existing operations support systems. For example, with ISDN a subscriber to the service can initiate and effect a move of his director or telephone number from one location to another without directly involving the operating company. The subscriber, by moving his directory number to a new location, now receives his service over a new transport facility. As a result, the records of the operating company which identify a specific transport facility to a specific telephone number cannot be readily updated to reflect subscriber moves. Thus, if the records of the operating company do not identify the transport facility which is associated with the directory number at the new location the operating company cannot readily process trouble reports against the service.