Packet transmission method and packet transmission device

摘要

A packet transfer method performed by packet transfer apparatuses provided in a packet sending side and a receiving side in a communication network for transferring a packet by determining a transfer destination by referring to destination information of the packet, wherein: two or more independent routes are set between the sending side packet transfer apparatus and the receiving side packet transfer apparatus; the sending side packet transfer apparatus inserts a sequence identifier for identifying sequence of packets into a send packet and copies the packet so as to send copied packets to all of the independent routes; the receiving side packet transfer apparatus compares (326) values of sequence identifiers of plural packets received from the independent routes with a value, CF, of a sequence identifier of an already sent packet so as to send a packet downstream in at least one packet having a value as the sequence identifier that is greater than the value, CF, of the sequence identifier of the already transferred packet and that is the least value among the values of the sequence identifiers of the plural packets received from the independent routes.