ABR FLOW CONTROL USING SINGLE BIT CONGESTION INDICATION AND WAVELET TRANSFORM FILTERING

摘要

A flow control system and methodology controls and avoids congestion in an Asynchronous Transfer Mode (ATM) network. The congestion state of a network switch is determined based on incoming Available Bit Rate (ABR) traffic, Constant Bit Rate (CBR) traffic, and Variable Bit Rate (VBR) traffic. High-frequency fluctuations due to VBR traffic are filtered out of the CBR/VBR traffic to determine the underlying trend of network traffic. A filtering mechanism is based on wavelet transforms. The switch congestion state is determined based on the current ABR traffic, the filtered CBR/VBR traffic, and the current status of buffers in the switch. The congestion state can then be used to adjust the ABR rate according to a feedback scheme such as Explicit Forward Congestion Indication (EFCI).