Performance analysis of feedback controlled data packet transmission over high-speed networks

The research on guaranteeing quality of services has been to a large extent focusing on satisfying cell-level performance such as cell loss rate, cell delay variation, etc. In the authors' previous work, they have used stochastic modeling techniques to evaluate the packet-level performance of two existing packet discarding schemes, packet tail discarding and early packet discarding, based on three packet-level performance measures: packet success probability, goodput, and badput. The work focused on the performance evaluation of data packet transmission over ATM unspecified bit rate (UBR) service. With the introduction of available bit rate (ABR) service, source regulation based on closed-loop control becomes increasingly important. In this work we analyze the performance of early packet discarding when the source transmission rates are governed by the feedback information from a congested ATM bottleneck node. Numerical study shows that the steady-state performance are largely affected by slow time scales of the feedback system. Nonetheless, the design of control threshold in early packet discarding is not significantly sensitive to the system time scales.