HG-RCP: A rate-based flow control mechanism for intranets interconnected by ATM networks

A number of distributed corporate intranets can be connected together using the ABR service of an ATM network to form a virtual private network. However, because the available bandwidth of the ABR connection may be occasionally reduced by the ATM network, severe congestion may occur at the gateway connecting an intranet to the ATM network. Such congestion is likely to cause packet loss at the gateway which in turn may significantly reduce the throughput of intranet applications. In order to address the above problem, we propose a novel rate-based flow control mechanism, called Ž . Host Gateway Rate Control Protocol HG-RCP , between the gateway and the intranet hosts. The control mechanism of HG-RCP is modeled as a classical feedback control system and the control parameters are selected to guarantee the stability of the system. The performance of HG-RCP is evaluated using simulation for both limited and unlimited buffers at the gateway. Simulation results confirm that HG-RCP is very stable and fair in allocating the ABR bandwidth among the competing sources in the intranet. It is also demonstrated via simulation that HG-RCP can significantly reduce the amount of buffers required at the gateway and improve the performance of TCPrIP applications in the intranets. q 1999 Elsevier Science B.V. All rights reserved.