Translator for IP networks, network system using the translator, and IP network coupling method therefor

A translator for coupling a first IP network in which a plurality of devices of interest are assigned first IP addresses such that the same first IP address is not assigned to two or more devices of interest, and a second IP network in which a plurality of devices of interest are assigned second IP addresses such that the same second IP address is not assigned to two or more devices of interest, said translator comprising:

• a header translator which translates a header between a first IP packet used in said first IP network and a second IP packet used in said second IP network in order to exchange information between said first IP network and said second IP network;
• and
• a storage which stores a plurality of IP addresses of a first class and a second class which are different from each other;
• wherein, for a header translation performed to send information from said second IP network to said first IP network, any of the plurality of IP addresses of the first class stored in said storage is assigned to an address of the second class stored in a source storing field included in an IP header of said second IP packet, and the assigned IP address of the first class is stored in a source storing field included in an IP header of said first IP packet;
• and
• for a header translation performed to send information from said first IP network to said second IP network, said second IP address stored in the source storing field included in the IP header of said second IP packet is assigned to an IP address of the first class stored in a destination storing field included in the IP header of said first IP packet, and the assigned IP address of the second class is stored in a destination storing field included in the IP header of said second IP packet.

A network system, comprising:

• a translator which includes:
• receiving means for receiving each of a first IP packet used in accordance with a first internet protocol and a second IP packet used in accordance with a second internet protocol from a network,
• packet translating means responsive to receiving of the second IP packet by said receiving means, for generating a first IP packet containing data included in said second IP packet, and responsive to receiving of the first IP packet by said receiving means, for generating a second IP packet containing data included in said first IP packet, and
• transmitting means for transmitting each of the first IP packet and the second IP packet generated by said IP packet translating means to said networks;
• and
• a host using said first packet passing through said network, wherein said host includes:
• host storage means for storing a plurality of first IP addresses assigned to respective devices of interest using the first IP packet,
• host address translating means operative when the first packet including data to be transmitted to a destination host using the second IP packet is sent to said network for assigning any of the plurality of first IP addresses stored in said storage means to a second address assigned to said destination host within second IP addresses assigned to respective devices of interest using the second IP packet and for storing the assigned first address in a destination storing field of the first IP packet, and
• means for sending address translation information including at least said second IP address assigned to said destination host and said first IP address assigned to said second IP address;
• and
• said translator further comprises:
• storage means for storing the address translation information sent from said host, and
• address translating means for extracting the second IP address from said address translation information stored in said storage means and for putting said second IP address into a destination storing field of said second IP packet.

A network systems comprising:

• a translator for mutually coupling a first IP network in which a plurality of devices in said first network are assigned respective first IP addresses, and a second IP network in which a plurality of devices in said second network are assigned respective second IP addresses
• wherein each of said first devices include:
• device storage means for storing a plurality of first IP addresses which are different from each other,
• device address translating means, operative when a first IP packet including data is to be transmitted to one of said second in said second IP network, for assigning any of the plurality of first IP addresses stored in said storage means to a second IP address assigned to said second device, and for storing the assigned first IP address to a destination storing field included in an IP header of said first IP packet, and
• means for sending address translation information including at least said second IP address assigned to said second device and said first IP address assigned to said second IP address;
• and
• wherein said translator includes:
• storage means for storing the address translation information sent from said first device, and
• packet translating means for translating a packet between said first IP network and said second IP network using said address translation information.

A method of coupling IP networks for mutually coupling through a translator a first IP network wherein a plurality of devices of interest are assigned first IP addresses of a first class such that the same first IP address is not assigned to two or more devices of interest, and a second IP network wherein a plurality of devices of interest are assigned second IP addresses of a second class such that the same second IP address is not assigned to two or more devices of interest, said method comprising the steps of:

• when initiating a communication between a first device of interest which is one of a plurality of devices of interest existing in said first IP network and a second device of interest which is one of a plurality of devices of interest existing in said second IP network, assigning any of a plurality of said first IP addresses of the first class to a second IP address of the second class assigned to said second device of interest;
• communicating between said second device of interest and said translator using said second IP address assigned to said second device of interest, and communicating between said translator and said first device of interest using said assigned first IP address of the first class;
• and
• releasing said assigned first IP address of the first class after termination of the communication.

A computer-readable recording medium storing a program for performing an internet protocol (IP) networking translation, said program for translation comprising:

• program code means for receiving a first internet protocol (IP) packet sent from a host which is identified by an IP address of a first class and a second IP packet sent from a host which is identified by an IP address of a second class;
• program code means for, in response to reception of the second IP packet by execution of said receiving code means, generating a first IP packet containing data included in the second IP packet, and in response to reception of the first IP packet by execution of said receiving code means, generating a second IP packet containing data included in the first IP packet;
• program code means for transmitting each of the first IP packet and the second IP packet generated to said network;
• program code means for storing a plurality of addresses assigned to respective devices of interest using the first internet protocol;
• and
• program code means for setting any of a plurality of first IP addresses stored by executing of storing program code in a source storing field of said first IP packet when generating said first IP packet from the received second IP packet.

A translator which is connected to a network, said translator comprising:

• a receiver;
• an internet protocol (IP) packet translator which, upon receiving a first IP packet from a host, generates a second IP packet having data included in the received first IP packet, p1 wherein said first IP packet is identified by an IP address corresponding to a first IP, and said second IP packet is identified by an address corresponding to a second IP;
• a storage which stores a plurality of IP addresses assigned to a plurality of destinations on said network according to said second IP;
• an address translator which sets any of said plurality of second IP addresses stored in said storage in a source storing field of said generated second IP packet;
• and
• a transmitter which transmits IP packets generated by said IP translator to said network.