Patent ID: 7281052

Claim:
A method of sending data from a first computer to a second computer connected within a network, the first and second computers configured to send the data using a layered sequence of data communication protocols, the layered sequence of data communication protocols comprising at least a first protocol layer and a second protocol layer, the method comprising: generating a first layer protocol data unit (PDU) by: (a) attaching a first header to the data at the first protocol layer of the first computer; and (b) reserving a space in the first header for an identifier; sending the first layer PDU from the first protocol layer to the second protocol layer of the first computer; generating a second layer PDU by: (a) attaching a second header to the first layer PDU at the second protocol layer of the first computer; (b) reserving a space in the second header for the identifier; (c) generating the identifier at the second protocol layer; and (d) storing the identifier in the reserved space of the second header and sending a copy of the identifier to the first protocol layer; sending the second layer PDU from the second protocol layer of the first computer to its corresponding second protocol layer of the second computer over the network; removing the second header from the second layer PDU at the second protocol layer of the second computer; copying the identifier from the reserved space in the second header to the reserved space in the first header; sending the first layer PDU from the second protocol layer of the second computer to the first protocol layer of the second computer; and removing the first header from the first layer PDU at the first protocol layer of the second computer.