NODE DEVICE AND LOOP DETECTION METHOD FOR LABEL SWITCHING PATH

摘要

PROBLEM TO BE SOLVED: To detect a loop efficiently and also in early stages by storing a flow identifier and first stage node information based on a label allocation message and deciding, whether or not the loop of a label switching path is formed in the case of receiving an allocation message including the same flow identifier and first stage node information from other node devices. SOLUTION: When a node device R1 produces a routing table to a destination address dest, a new label (a) is allocated and a label allocation message m1 is sent to a node device R2 that is the next hop node to the destination dest in an output interface to the device R2. When the device R2 receives the message m1 from the device R1, it allocates a new label in an output interface to the next hop node device R3 of a self-node and sends a label allocation message m2 to the device R3.