Mathematical modelling of the Internet
Frank P. Kelly · 2000
Abstract In the current Internet, the rate at which a source sends packets is controlled by TCP, the transmission control protocol of the Internet [8], implemented as software on the computers that arc the source and destination of the data. The general approach is as follows. When a resource within the network becomes overloaded, one or more packets are lost; loss of a packet is taken as an indication of congestion, the destination informs the source, and the source slows down. The TCP then gradually increases its sending rate until it again receives an indication of congestion. This cycle of increase and decrease serves to discover and utilize whatever bandwidth is available, and to share it between flows. In the future, resources may also have the ability to indicate congestion by marking packets, using an Explicit Congestion Notification mechanism [4], and current questions concern how packets might be marked and how TCP might be adapted to react to marked packets.