A Fair and Efficient SOM-based Feedback Congestion Control in ATM Networks

Abstract

The ATM Forum has chosen the rate-based congestion control for Available Bit Rate (ABR) services. Many rate-based schemes, such as the Forward Explicit Congestion Notification (FECN), the Backward Explicit Congestion Notification (BECN), the Proportional Rate Control Algorithm (PRCA) and the Self-Detective Congestion Control (SDCC), have been proposed. The FECN and BECN schemes use negative feedback rate control. Overall network collapse may occur, if all notification cells of these two schemes in the backward direction experience severe congestion. The PRCA scheme uses positive feedbacks to solve drawbacks of the FECN and BECN schemes, but unfair distributions of the available network bandwidth among ABR VCs may occur. The SDCC scheme use intelligent holding to solve this problem, but it needs to know the bottleneck switch in advance. To resolve problems of the existing rate-based schemes, a new adaptive congestion control scheme, i.e., the SOM-based Feedback Congestion Control (SFCC) scheme, is proposed to achieve high utilization, low cell loss rate and fair bandwidth allocation among ATM ABR VCs in this paper.