Effect of timeout retransmissions on end-to-end delay in packet switching networks

Abstract

An end-to-end error recovery scheme is a promising way to obtain low end-to-end delays in packet switching networks. However, a too-short timeout interval may cause unnecessary packet retransmissions even when a packet is transmitted successfully to the receiver. On the other hand, a longer timeout interval may introduce large end-to-end delay when a packet is actually lost. Thus, it becomes important to determine an appropriate timeout period in the scheme. This paper analyzes a tandem queueing network system with blocking due to finite capacity in intermediate nodes and investigates the effect of the timeout period on the end-to-end delay performance. It is found that there exists the timeout period minimizing the mean packet transmission delay in the end-to-end error recovery scheme. The delay performance between end-to-end and link-by-link error recovery schemes also is compared and it is found that the delay performances of these schemes are influenced significantly by the node-to-node delay.