Patent ID: 7304959
Filing Date: 2007-12-04
Classification: H04L

Abstract:
1. A method for determining when to transmit a probe packet to detect increases in path maximum transmission unit (PMTU) in a network having a host system and a target system interconnected by the network, comprising: calculating a utility variable corresponding to a number of packets to be transmitted from the host system to the target system which are greater than a predetermined amount of a known PMTU for the target system, the calculating including retrieving from a destination cache, a learned path maximum transmission unit (LPMTU) and a previous path maximum transmission unit (PPMTU) corresponding to a route to the target system and comparing a size of each packet to be transmitted from the host system to the target system with the LPMTU for the target system, and for each packet exceeding a threshold packet size, incrementing the utility variable; and when the utility variable is greater than a predetermined utility threshold, sending instructions to the host system to send a probe packet to detect increases in PMTU for the target system.