Patent ID: 7106742

Claim:
A digital data system comprising a link that carries message packets, a first node sending a plurality of message packets to a second node on the link as a sequence of message packets, with each message packet being sent from the first node with a sequence identifier, and each message packet comprising an initial portion comprising an error code, the second node (i) inspecting the error code for each packet received on the link to detect an error condition, and (ii) returning a control symbol along with the sequence identifier of the received packet to the first node based on the result of that inspection, the second node returning the control symbol to the first node before the entire message packet has arrived at the second node, and the first node responding to the control symbol to control the further transmission of message packets to the second node over the link wherein the second node returns a packet-not-accepted control symbol to the first node indicating receipt on the link of a message packet that is out of sequence and wherein the first node responds to the packet-not-accepted control symbol by re-sending a portion of the sequence of message packets.