A simulation study of interoperative methods for congestion control over TCP/ATM

Abstract

ATM rate-based flow controls can effectively reduce cell losses and buffer requirement in ATM switches, and thus enhance overall performance in ATM networks. However, many simulation studies show that the performance of TCP can be reduced over ATM networks in some situation like network congestion. This comes from the absence of direct channel between TCP and ATM protocol stack. That is, the ATM layer in a host does not notify TCP of the congestion information from ATM networks through resource management (RM) cells. So, TCP may generate vast packets regardless of present network status. In this paper, we introduce the direct mechanism, interoperative method between TCP and ATM protocol stack and perform a simulation in order to justify our mechanism. The simulation results, by SIMNET from NIST, show that the TCP adopting mechanism has better performance over that only with ATM congestion control mechanism.