The internal centralized Attendant servcices group (CASINT) is assigned in the home node. This function enables the entire range of attendant functions of an ATNDGR to be transferred to another ATNDGR. If an attendant group takes on the attendant terminal traffic of another ATNDGR in addition to its own, it functions as a central attendant group. Thus, an ATNDGR which takes over the functions of another ATNDGR within the same node is known as an internal Centralized Attendant Services group (CASINT). The assignment of an ATNDGR is entered as a night option with the AMO NAVAR, which is in turn assigned to another ATNDGR (CASINT). Only one CASINT may be assigned to a night option. Please note that an ATNDGR must be allocated at least one normal night option. A CASINT may also switch over to an internal night option. The CASINT can only be operated as a night variant, even if no ATND is assigned.