| An ATM switch consisting of multiple ATOM switch elements operating in parallel may lead to some switch elements idle in the period of one slot time. This thesis proposes a new operating scheme called cyclic shifting scheme (CSS) for the switch with a number of output-buffered switch elements. The computer simulation result shows that the new scheme can improve the performance of the switch. The new design can be efficient for both uniform and non-uniform traffic.; In order to study the performance of the switch, four dropping policies for TCP over ATM, which are tail dropping (TD), drop from front (DFF), partial package discard (PPD) and early package discard (EPD) are adopted in the study. The thesis also introduces a new dropping scheme called early packet discard from front (EPDFF). The computer simulation result shows that the EPD outperforms other schemes in terms of throughput and delay. The EPDFF is better than EPD for small buffer sizes but EPD becomes better than EPDFF for the larger buffer sizes. |
