The Role of Information Update in Flow Control

A common feature of congestion control protocols is the presence of information packets used to signal congestion. We address here the question of how frequently such protocols need to generate information packets in order to optimize their performance. Through a number of congestion control models, we identify and quantify different types of effects of the frequency of generating information packets. We consider both TCP-type protocols, in which controlling the frequency of information packets is done through static or dynamic delayed ACK options, as well as ATM type flow control, where the optimal time spacing between the generation of network management packets is computed. We show how the spacing between information packets influences the throughput and the stability of the system.