Controllability and impact of the cell loss process in ATM networks

Cell loss measurements have been carried out for a conceivable ATM network scenario employing three types of ATM cross connects. By measurement, and compared to theory, adequate performance levels were readily obtained in terms of e.g. long-term CLR (cell loss ratio). The long-term CLR does not however provide enough information about the temporal distribution of the cell loss process. In view of this fact we conclude that short-term CLR for a cell loss burst better signifies the deterioration of a service. In these measurements the short-term CLR was high, 4 to 10%, and with a constant average level regardless of network load level. The acceptable cell loss level is determined only by how users perceive the quality of service. By both objective analysis and subjective assessment the relationship between network performance and quality of service is investigated for a high quality video/audio codec implementation.