A comparative performance study of various congestion controls for ISDN frame-relay networks

Abstract

Detailed simulation results are presented to illustrate the throughput performance of various congestion control schemes that have been considered when using link access protocol D as the level-2 protocol. Three classes of adaptive window schemes, all of which use implicit detection, are examined. In all of them, receiving a REJECT frame (which is sent by the far end when it receives an out-of-sequence frame) is interpreted as a sign of congestion, and the control action taken by the end-systems is in the form of reducing their layer-2 window. It is shown that these schemes perform fairly well over a wide range of network parameters and traffic patterns, with one in particular providing a very robust performance over the range. It involves reducing the window size to 1/2 upon receiving a REJECT frame.<>