Patent ID: 7788408

Claim:
A message processing method for a first server which transfers, between a first network according to a first addressing system and a second network according to a second addressing system, a message which includes a first region and a second region, and a second server coupled to the first server, the method comprising the steps of: translating, in the first server, a Layer 3 address of the first addressing system into a Layer 3 address of the second addressing system in the first region corresponding to a Layer 3 region of the message when the message is received from the first network; detecting, in the first server, on the basis of a port number in a header of the message, whether the message is a predetermined protocol which describes a Layer 3 address in the second region corresponding to a Layer higher than Layer 3; creating, in the first server, translation information including a correspondence relationship between the Layer 3 address of the first addressing system and the Layer 3 address of the second addressing system for translating a Layer 3 address contained in the second region corresponding to a Layer higher than Layer 3, if the message is the predetermined protocol; sending from the first server to the second server, the translation information and the second region; translating, in the second server, on the basis of the translation information, a Layer 3 address between the first addressing system and the second addressing system in the second region if a Layer 3 address is extracted from the second region; sending from the second server to the first server, the second region including the Layer 3 address which has been translated by the second server; receiving, at the first server, from the second server, the second region including the Layer 3 address which has been translated; and transferring the first region in which the Layer 3 address translated by the first server and the second region including the Layer 3 address which has been translated by the second server, to the second network according to the Layer 3 address in the first region corresponding to Layer 3.