Throughput analysis in transport layer over ATM networks: case of generally distributed packet length

Various types of ATM switching fabrics have been proposed and developed. Among them, the output buffered ATM switch like the Knockout switch has been extensively studied because of its high throughput performance. The throughput performance of ATM switches has been derived mainly at the cell level so far. Nevertheless, the protocol data unit (PDU) of the transport layer is a packet, which is divided into several cells for transmissions over ATM networks and the error recovery is performed at the packet level. We study the maximum throughput at the packet level, i.e., in the transport layer over ATM networks with selective repeat ARQ. In the analysis, we suppose that sources steadily generate cells due to packet retransmissions: the state is referred to as source saturation, which makes the analysis very tractable from a computational point of view and enables us to treat a general distribution for the packet length. Through the numerical results, we show the impacts of the distribution of the number of cells in a packet, the buffer size of ATM switches the peak rate and the number of sources on the throughput performance