Port selected packet discarding scheme in ATM networks

Early Packet Discard (EPD), one of the congestion control schemes at ATM switch in IP over ATM networks, enables us to use efficiently the link bandwidth and buffer space. However there is a problem that buffer overflow occurs, when many links are connected to the ATM switch and packets arrive at the ATM switch from most of them. In this paper, we propose a new packet discarding scheme in which the number of ports accepted at the same time is taken into account. In the proposed scheme, by using two thresholds, packets are discarded according to the number of ports accepted at the same time. By computer simulations, we evaluate a badput and a throughput of the proposed scheme and compare them with those of the conventional scheme. As a result, we show our proposed scheme can improve badput performance without causing the degradation of the throughput.