Patent ID: 8289858

Claim:
A method of determining round-trip delay and jitter in an optical network, comprising the steps of: a) transmitting a test frame over the optical network from an Optical Line Termination unit in the optical network to a plurality of Optical Line Units, a plurality of Optical Network Units, or both, in the optical network, each test frame identified by a Gigabit Passive Optical Network (â€œGPONâ€) Encapsulation Method tag that is unique to each Optical Line Unit or Optical Network Unit and including a time stamp generated by the Optical Line Termination Unit using a time reference of the Optical Line Termination Unit; b) receiving, at the Optical Line Termination Unit, a looped-back test frame from each of the plurality of Optical Line Units, the plurality of Optical Network Units, or both, over the optical network, wherein the test frame has been looped-back in data link layer (Layer 2) hardware circuitry that is not a processor, the time references of the plurality of Optical Line Units and the plurality of Optical Network Units are not aligned to the time reference of the Optical Line Termination Unit, and the looped-back test frame was not time-stamped at the ONU; and c) determining a round-trip delay measurement based on a difference of the time stamp generated by the Optical Line Termination unit and included in the looped-back test frame and the time the Optical Line Termination unit received the looped-back using the time reference of the Optical Line Termination Unit used to generate the time stamp.