Patent ID: 7835290

Claim:
A method for measuring an end-to-end delay in an asynchronous packet transfer network that supports class-based traffic, the method comprising the steps of: a) transmitting, by a packet transmitter, a higher priority packet and a lower priority packet at an ingress node; b) measuring, by a packet receiver, a time when the higher priority packet arrives at an egress node; c) measuring, by a packet receiver, a time when the lower priority packet arrives at the egress node; and d) calculating, based on the measurements in b and c, a delay time for measuring the end-to-end delay, the delay time being a time difference between the time when the higher priority packet arrives at the egress node and the time when the lower priority packet arrives at the egress node, wherein: the higher and lower priority packets each include a Coupled Label field, and a Sequence Number field for discriminating one of the packets that are repeatedly transmitted; the Coupled Label field of the higher priority packet is recorded with a label value of the lower priority packet; and the Coupled Label field of the lower priority packet is recorded with a label value of the higher priority packet.