Patent ID: 7136356

Claim:
A packet data transfer method for an IP (Internet Protocol) network or an MPLS (Multi-Protocol Label Switching) network, comprising the steps of: retaining flow identifier data for identifying data to be processed and control code identifier data for controlling the processing for each of a plurality sets of packet data, in a packet data transfer apparatus having a plurality of Input and Output ports; receiving the plurality of sets of packet data transmitted via respective data packets converted from a meaningful frame or slice of audiovisual data, said data packets provided with said flow identifier data and said control code identifier data; and in discarding packet data identified by the flow identifier data upon congestion in the packet data transfer apparatus, performing discard initiation or termination based on said control code identifier data, wherein the discard is initiated at an initial data packet of the meaningful frame or slice of audiovisual data rather than at a middle data packet of the meaningful frame or slice of audiovisual data.