CELL EXCHANGE WITH ABORT PRIORITY CONTROL FUNCTION

摘要

PROBLEM TO BE SOLVED: To attain proper abort priority control while keeping a feature of excellent utility efficiency of a buffer memory by using the buffer memory in common for a plurality of incoming and outgoing lines of a common buffer ATM switch. SOLUTION: An SBM threshold setting section 8 calculates a threshold level by the following algorithm based on a specific table in response to a state of channels contained by a cell exchange. (1) A channel having the highest rate of high priority cells is selected among contained channels and the number of buffers required when only one channel having a load equal to the rate is in existence is obtained. (2) The number of buffers to be added when one channel with a load factor equal to the rate of the remaining channels with respect to the high priority cells regarded to be equal to that of the channel selected in the items (1) above is added to the number of buffers obtained by (1). (3) A threshold is set by subtracting number of buffers obtained by (2) above from the total buffer number.