Effectively Controlling Datagram Congestion on the DoD Internet System Gateways

摘要

Nagle proposes to replace the single queue per outgoing channel with multiple queues, one for each source with datagrams passing through the gateway. Datagrams are removed from these queues one at a time in a round robin fashion. This procedure ensures each source is allotted a fair share of the channel bandwidth. The study found, through simulation, that this method insulated well behaved host from the presence of a badly behaved host. Badly behaved host are in effect punished through increased delay while well behaved host receive their fair share of the network resources. This researcher recommends Nagle's method be implemented for testing on the Internet. Zhang proposal is basically a feedback method of congestion control. This method allows a gateway to control the rate at which host send datagrams through the gateway. This requires modification to the IP modules in the hosts and gateways and modification to the Source quench message. These modifications will allow the gateways to sense traffic levels and to tell the host what rate to transmit at and for how long. However, Zhang did not define two parameters which are critical to the performance of her method. Both of these parameters depend on the Internet traffic profile which is not known at the present. Because these parameters are not defined, this study could not simulate the performance of Zhang's method. However, this researcher does recommend Zhang's method for future study.