Patent ID: 6970481

Claim:
In a variable delay network that includes a transmitter and a receiver, a transmitter application associated with the transmitter configured to transmit a stream of multimedia packets through a transmitter link layer controller, over the variable delay network, through a receiver link layer controller to a receiver application associated with the receiver, the transmitter link layer controller having an undedicated variable delay interface with the transmitter application, the transmitter link layer controller and the receiver link layer controller being substantially synchronized in accordance with a common network time base, a method of the transmitter link layer controller emulating a constant delay network over the variable delay network despite the undedicated variable delay interface, the method comprising the following: receiving a first multimedia packet from the transmitter application, the first multimedia packet including a first transmitter application time stamp, which represents the relative time that the information in the first multimedia packet should be rendered by the receiver application in accordance with a transmitter application time base; including in the first multimedia packet a first network time stamp, which represents the relative time that the information in the first multimedia packet should be rendered by the receiver application in accordance with the common network time base; receiving data representing a frequency of the transmitter application time base; receiving a second multimedia packet from the transmitter application, the second multimedia packet including a second transmitter application time stamp, which represents the relative time that the information in the second multimedia packet should be rendered by the receiver application in accordance with the transmitter application time base; calculating a second network time stamp representing the relative time that the information in the second multimedia packet should be rendered by the receiver application in accordance with the common network time base, wherein the calculation includes adding to the first network time stamp, a difference between the second transmitter application time stamp and the first transmitter application time stamp to create a sum that is multiplied by the received frequency of the transmitter application time base; including the second network time stamp in the second multimedia packet; and dispatching the second multimedia packet to the receiver application.