Abstract: Fairness is provided among network sessions contending for available bit rate (ABR) service in an asynchronous transfer mode network by determining congestion information on a per port basis. ABR cells are monitored to determine which rate information per outgoing port based on ABR cells leaving a switch. Using the ABR per port rate, the available capacity, and the input rate to output queues, a link congestion parameter (LCP) is determined. Resource Management (RM) cells traveling through the switch are monitored to determine whether the new LCP is lower than the explicit rate (ER) field in RM cell. If the new LCP is lower, the new LCP is stuffed into the RM cell. When the sender receives the LCP value, the sender output rate is adjusted based on the LCP. Because LCP is determined based on per port traffic flow, fairness is provided among session competing for available ABR capacity.

Abstract: The benefits of Transport Control Protocol (TCP) over Available Bit Rate (ABR) Service of an Asynchronous Transfer Mode (ATM) network is extended to the entire TCP connection by intercepting and modifying TCP congestion control information in accordance with resource information associated with the TCP connection. An algorithm calculates a new advertised window size based on various network resource parameters, such as ABR. The advertised window is adjusted if the newly calculated window size is smaller than the advertised window size. By adjusting the TCP window, the normal extreme fluctuations of the TCP window are avoided.