Patent ID: 6973270

Claim:
A routing control method in an optical packet switching network including a plurality of optical packet switches, each optical packet switch having a plurality of output ports used for sending packets to other optical packet switches, respectively, said method comprising the steps of: in a one optical packet switch, monitoring congestion conditions at its output ports; in said one optical packet switch, transferring packets to be stored in a one output port that is judged in said monitoring step as in congestion, to other output port that is judged in said monitoring step as not in congestion; from said one optical packet switch, sending the packets as reflection packets via said other output port to an other optical packet switch corresponding to said other output port; and from said other optical packet switch, returning said reflection packets to said one optical packet switch, wherein said transferring step comprises selecting said other output port in random from output ports judged in said monitoring step as not in congestion so as to provide reflection routes with transmission delay times within a predetermined range.