Patent ID: 7113486

Claim:
A method of measuring variation in propagation delay for network packets transmitted from a transmitting station to a receiving station, wherein a first periodic process at the transmitting station progresses at substantially the same frequency as a second periodic process at the receiving station, said method comprising the steps: a) generating a network packet, b) encapsulating a plurality of data packets in the network packet, c) generating an outgoing time stamp and inserting the outgoing time stamp into the network packet, said outgoing time stamp substantially representing a degree of progression of the first periodic process at the time of including the outgoing time stamp in the network packet, d) transmitting the network packet from the transmitting station to the receiving station, e) receiving said network packet at the receiving station, f) generating an incoming time stamp and adding said incoming time stamp to the network packet, said incoming time stamp substantially representing a degree of progression of the second periodic process at the time of receiving said network packet, g) comparing the incoming time stamp to the outgoing time stamp to obtain a first delay measurement for the network packet, h) repeating steps a–g at least twice to obtain at least second and third delay measurements, and i) comparing the first, second and third delay measurements to obtain maximum and minimum delay measurements and comparing the maximum and minimum delay measurements.