Patent ID: 7876778
Filing Date: 2011-01-25
Classification: H04L

Abstract:
1. A method for packet transfer between a first communication network over which data communication is performed with a first communication protocol, and a second communication network over which data communication is performed with a second communication protocol, the method comprising: storing a first destination correspondence information containing correspondences between destination information of packets under the first communication protocol and destination information of packets under the second communication protocol for transferring packets under the first communication protocol to the second communication network, the first destination correspondence information further including correspondences between the destination information of packets under the first communication protocol and protocol types for the packets under the first communication protocol prior to the packets having been converted into the packets under the first communication protocol, receiving a first packet under the first communication protocol generated by conversion of a first packet under a third communication protocol from the first communication network, based on the first destination correspondence information, determining destination information of a first packet under the second communication protocol corresponding to destination information of the first packet under the first communication protocol received from the first communication network, generating a header of the first packet under the second communication protocol, based on the determined destination information of the first packet under the second communication protocol, converting the first packet under the first communication protocol received from the first communication network into a first packet under the third communication protocol, converting the first packet under the third communication protocol generated by the conversion into the first packet under the second communication protocol by adding the header of the first packet under the second communication protocol generated based on the determined destination information of the first packet under the second communication protocol to the first packet under the third communication protocol generated by the conversion, transmitting the packet under the second communication protocol generated by the conversion to the second communication network, receiving at least one of a second packet under the first communication protocol generated by conversion of a second packet under the third communication protocol, and a third packet under the first communication protocol generated by conversion of a first packet under a fourth communication protocol from the first communication network; based on the first destination correspondence information, determining a respective protocol type for each of the at least one of the second and third packets under the first communication protocol corresponding to destination information included within respective header information of the packet; for each of the at least one of the second and third packets under the first communication protocol, upon determining the respective protocol type for the packet to be the third communication protocol, converting the packet from the first communication protocol into a corresponding packet under the third communication protocol; converting each corresponding packet under the third communication protocol converted from the at least one of the second and third packets under the first communication protocol into a corresponding packet under the second communication protocol; for each of the at least one of the second and third packets under the first communication protocol, upon determining the respective protocol type for the packet to be the fourth communication protocol, converting the packet from the first communication protocol into a corresponding packet under the fourth communication protocol; and converting each corresponding packet under the fourth communication protocol converted from the at least one of the second and third packets under the first communication protocol into a corresponding packet under the second communication protocol.