Active Queue Management

Active Queue Management

Michele Mara de Araújo Espíndula Lima (Federal University of Pernambuco, Brazil) and Nelson Luís Saldanha da Fonseca (State University of Campinas, Brazil)
Copyright: © 2008 |Pages: 6
DOI: 10.4018/978-1-59140-993-9.ch001
OnDemand PDF Download:
No Current Special Offers


Although powerful and necessary to prevent network collapse, the congestion control mechanism of the TCP is not sufficient to avoid congestion. Since TCP sources exert a limited control of the network, and unresponsive flows, which do not slow down their sending rates when congestion occurs, may be present, the efficacy of end-to-end congestion control also relies on queue mechanisms at the routers.

Key Terms in this Chapter

Global Synchronization Problem: A phenomenon that happens when most of active TCP flows lose packets, reducing their sending rates, which can lead to network underutilization.

Round Trip Time: Time elapsed between the transmission of a packet and the reception of the corresponding acknowledgement.

Congestion Window: Range of packets that can be transmitted by a sender without leading to network congestion.

Congestion: State of the network characterized by the demand of traffic transmission exceeding its transport capacity.

Congestion Control: Traffic control mechanisms that remedy the consequences of congestion problems that have already occurred.

Congestion Avoidance: Traffic control mechanisms that attempt to avert the occurrence of network congestion.

Tail Drop: A policy, which admits packet into the router buffer whenever there is available space.

Active Queue Management (AQM): Congestion control mechanism for the early notification of incipient congestion pursued by dropping/marking packets.

Random Early Detection Policy (RED): An AQM policy recommended by the Internet task engineering force for deployment on the Internet.

Transmission Window: Range of packets that can be transmitted by a sender.

Complete Chapter List

Search this Book: