End-to-End Adaptive Congestion Control in TCP/IP Networks

4

Measuring Network Congestion

CONTENTS

4.1 Overview

4.2 Drop Tail

4.3 Congestion Early Warning

4.3.1 Packet Drop Schemes

4.3.2 Packet Marking Schemes

4.4 Concluding Comments

4.1 Overview

End-to-end congestion control in computer networks, including the current Internet, requires some form of feedback information from the congested links to the sources of data traffic, so that they can adjust their rates of sending data according to the bandwidth available. Such feedback information can be transmitted either explicitly or implicitly.

In the case of implicit feedback, the network transport layer protocol tries to maintain high throughput and low delay of data packets by estimating the congestion level of the network, based on changes in ...