A network communication controller that provides for rapid detection of available buffer capacity and transmission of pause frames as needed to provide flow control is described. The transmission of a pause frame is requested when a reception buffer capacity achieves an almost full condition. Additionally, an almost empty condition can be used to trigger the transmission of another pause frame. In either case, the pause frames are automatically generated and transmitted ahead of other frames that may also be waiting for transmission. Preferably, the network communication controller is an integrated circuit including circuitry for a MAC layer and a MAC control layer. The flow control provided by the invention is particularly suitable for high speed networks, e.g., 1 Gbps Ethernet networks.