DESIGN AND ANALYSIS OF THE GCRA TRAFFIC SHAPER FOR VBR SERVICES IN ATM NETWORKS

The proposed GCRA (Generic Cell Rare Algorithm) traffic shaper consist s of a regulator and a scheduler. It can shape multiple incoming VER ( Variable Bit Rate) cell streams simultaneously to be strictly conformi ng according to the GCRA algorithm when the cells depart for the ATM o utput link. The impact of cell emission conflicts is considered and re solved by using an EDD (Earliest-Due-Date) scheduler and a feedback si gnal from the scheduler to the regulator. The call admission control c ondition and the cell delay bound are derived. Simulation re suits dem onstrate that the output cell streams of the proposed GCRA traffic sha per do not contain any non-conforming cells and the scheduler queue si ze is significantly reduced. Mean while, the delay performance is almo st not affected by the use of the feedback mechanism.