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Abstract : |
of a delay-bandwidth product) that were full much of the time; this would significantly increase the average delay in the network. Therefore, with increasingly high-speed ways for congestion avoidance in packet-switched net- networks, it is increasingly important to have mechanisms works. The gateway detects incipient congestion by com- that keep throughput high but average queue sizes low. puting the average queue size. The gateway could notify In the absence of explicit feedback from the gateway, connections of congestion either by dropping packets ar- there are a number of mechanisms that have been proriving at the gateway or by setting a bit in packet headers. posed for transport-layer protocols to maintain high through-When the average queue size exceeds a preset threshold, put and low delay in the network. Some of these proposed the gateway drops or marks each arriving packet with a mechanisms are designed to work with current gateways certain probability, where the exact probability is a func- [15, 23, 31, 33, 34], while other mechanisms are coution of the average queue size. pled with gateway scheduling algorithms that require per-RED gateways keep the average queue size low while connection state in the gateway [20, 22]. In the absence of allowing occasional bursts of packets in the queue. During explicit feedback from the gateway, transport-layer proto-, |
