Fixing timeout intervals for lost packet detection in computer communication networks

In a packet-switched data communication network which provides internal packet accountability via an end-to-end positive acknowledgment protocol, it is necessary to include a mechanism for detection and retransmission of missing packets. In particular, a decision must be made as to how long a sending element should reasonably wait before declaring an unacknowledged packet lost and initiating a recovery action. This waiting time is one of a class of system parameters which have come to be known as timeout intervals. The choice of a timeout interval is a delicate problem. 1 , 2 If it is too short, network capacity is wasted by frequent unnecessary actions for packets which are not lost but merely delayed. If the timeout interval is too long, lost packets cause needlessly prolonged delays before recovery is initiated.