Reverse traffic reduction in the Fuzzy Logic based dual explicit congestion notification mechanism in satellite TCP/IP networks

A mechanism for reducing reverse traffic in the Fuzzy Logic based dual explicit congestion notification mechanism is proposed for satellite TCP/IP networks. A linguistic hedge based Backward Explicit Congestion Notification (BECN) activation function is employed in order to ensure that reverse traffic is generated only when congestion is extremely high. A source initiated RTT reverse traffic reduction routine that resets the BECN Capable Transport (BECT) bit in the IP header is also employed in order to stop the router from generating more reverse traffic within a roundtrip time (RTT) after the sender has already responded to the congestion signal. This algorithm is compared with the basic fuzzy logic based dual explicit congestion notification mechanism and the fuzzy logic based dual explicit congestion notification mechanism, which uses a router computed RTT based decay function for reverse traffic minimization. Performance evaluation is carried out by using both web-traffic loads, a varying number of FTP flows and a varying number of router buffer sizes. Simulation results show that the proposed approach reduces BECN Internet Control Message Protocol (ICMP) Source Quenches significantly by more than 75% while the RTT based decay function approach achieves a 40% reduction; both approaches do not degrade the packet loss rate and the link utilization.