Abstract: To enhance the performance and buffer usage of ATM switch, we compares the performance of buffer allocation strategies in shared buffer ATM switches under VBR load by computer simulation. We compare the four strategies from two aspects: cell loss ratio (R), mean delay(D). By the comparison,we find that the performances of buffer allocation strategies in shared buffer ATM switches are relate to traffic measure of the ATM switches. In general, the strategies that have buffer sharing are better than that have no buffer sharing.The strategy that has some measures used to prevent some output ports from occupying almost all buffer are better.

Key words: ATM, buffer allocation strategy, VBR, uniform, non-uniform