PERFORMANCE ANALYSIS OF THE UPC NPC ALGORITHM FOR GUARANTEED QOS IN ATM NETWORKS/

It is well known that if usage parameter control/network parameter con trol (UPC/NPC) functions are used together with a cell loss priority c ontrol scheme in ATM networks, the measurement phasing problem can occ ur. This makes it difficult for a network provider to define and commi t the cell loss ratio as a QoS parameter. To solve the problem, we pro pose a new UPC/NPC algorithm. By using the proposed UPC/NPC algorithm, we can define the cell loss ratios for CLP = 0 and CLP = 0+1 cell str eams without the measurement phasing problem under any conditions. We analyzed the performance of the proposed UPC/NPC algorithm. Using a di screte time model for the UPC/NPC architecture with a discrete-time se mi-Markov process (DSMP) input model, we obtained the cell discarding probabilities of CLP = 0 and CLP = 0+1 cell streams and showed that mo re CLP = 0 cells are accepted compared to what was proposed in ITU-T.