A two-level flow control scheme for ABR traffic in ATM networks

In this paper, a new two-level flow control scheme using VP credit-based control and stop-and-go rate control for Asynchronous Transfer Mode (ATM) networks is presented. Since the proposed scheme does not require any information on traffic characteristics, we propose to apply such a flow control scheme to the best effort traffic that requires no bandwidth guarantee From the network. The proposed flow control scheme can efficiently use the leftover bandwidth after the guaranteed traffic has been satisfied. Therefore, high bandwidth utilization can be achieved. Furthermore, cell loss can completely be avoided by the lower-level credit-flow control done on a per VP basis. On top of this, a higher-level Explicit Congestion Notification (ECN) rate control is employed to avoid any performance degradation. Simulations have been performed to verify the effectiveness of the proposed scheme. It is found that the average end-to-end delay of our proposed scheme is better than that of the original VCFC scheme [1]. In addition, there is also a tremendous saving in the memory required when compared with the VCFC scheme.