Window-based ATM cell stream regulator

Claim 1

A window-based ATM cell stream regulator comprising: arrival time detecting means for detecting an arrival time of an arriving cell; arriving cell detecting means for detecting to which connection, among a plurality of connections, the arriving cell belongs; memory means for storing therein a predetermined allowable number, a predetermined upper limit number greater than the allowable number, a predetermined window section length indicating a predetermined single window length, a predetermined reset time, a counted number of arriving cells and a window start time that is an initial value and will be updated; window detecting means for detecting to which window of a connection the arriving cell belongs based on the arrival time, the window start time and the window section length; counting means for counting a number of cells which have arrived in each connectionu, and for counting a number of cells, that have arrived until a number of the counted cells in a single window exceeds the allowable number and reaches the upper limit number, and then designating the counted number of cells having reached the upper limit number as an allowable number of cells; allowable number updating means for updating the counted number stored in said memory means to the allowable number of cells, which have been counted by said counting means, as a counting number in a succeeding window on a time base; discarding means for discarding cells which arrive after the counted number of cells reaches the upper limit number; counted number updating means for updating the counted number if the arrival time is later than the window start time by an amount no less than the predetermined window section length, and less than the reset time; window updating means for updating the window start time if the arrival time is later than the window start time by an amount no less than the window section length and less than the reset time; resetting means for updating the counted number if the arrival time is later than the window start time by an amount no less than the reset time; and reset updating means for updating the window start time if the arrival time is later than the window start time by an amount no less than the reset time.