Mobile IP communication scheme for supporting mobile computer move over different address spaces

• US 20050281285A1
• Filed: 08/02/2005
• Published: 12/22/2005
• Est. Priority Date: 09/05/1997
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ishiyama, Masahiro, Inoue, Atsushi, Fukumoto, Atsushi, Tsuda, Yoshiyuki
• Granted Patent: US 7,586,939 B2
• Time in Patent Office: Days
• US Class Current: 370/465
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• CPC Class Codes: H04L 61/2585 through application level gateway [ALG]
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 61/5084 Providing for device mobility network addressing or numbering for mobility support in wireless networks H04W8/26; mobile IP H04W80/04
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/0464 using hop-by-hop encryption, i.e. wherein an intermediate entity decrypts the information and re-encrypts it before forwarding it
• CPC Class Codes: H04W 12/02 Protecting privacy or anonymity, e.g. protecting personally identifiable information [PII]
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A mobile IP communication scheme for supporting a mobile computer moving over different address spaces is disclosed. A packet relay device for relaying packets having an address of the mobile computer device as a destination or source is provided at a border between a private address space and a global address space, where the packet relay device has a packet receiving unit for receiving a packet in a first format using a global address which is transmitted by the mobile computer for a location registration from a visited site managed by a global address system, and checking a content of the packet, and a packet transfer unit for transferring the packet in a second format using a private address, to a correspondent computer in a home network of the mobile computer managed by a private address system, according to the content of the packet.

Claims

1. A packet relay device in a network system supporting a mobile computer that is capable of carrying out communications while moving over a plurality of interconnected networks, for relaying packets having an address of the mobile computer as a destination or source, the packet relay device comprising:

a packet receiving unit configured to receive a packet in a first format using a global address which is transmitted by the mobile computer for a location registration at a home network from a visited site managed by a global address system which is valid throughout the inter-connected networks, the packet being transmitted by using a global address of the packet relay device, and to check a content of the packet; and

a packet transfer unit configured to transfer the packet in a second format using a private address, to a correspondent computer in the home network of the mobile computer managed by a private address system which is valid only within the home network, according to the content of the packet, the packet being transferred by using a private address of the correspondent computer which is different from the packet relay device identified by the global address of the packet received by the packet receiving unit.

2. The packet relay device of claim 1, wherein:

the packet receiving unit decrypts the packet received from the mobile computer at the visited site using a key corresponding to the mobile computer, and

the packet transfer unit re-encrypts a decrypted packet using a key corresponding to the correspondent computer, encapsulates an encrypted packet by attaching a header having a private address of the packet relay device as a source and a private address of the correspondent computer as a destination, and transfers an encapsulated packet to the correspondent computer.

3. The packet relay device of claim 2, further comprising:

a first memory unit configured to store the private address of the packet relay device and the global address of the packet relay device, which are used by the packet receiving unit and/or the packet transfer unit; and

a second memory unit configured to store a current location address of the mobile computer at the visited site, a home address of the mobile computer in the home network, and a key information indicating the key corresponding to the mobile computer, which are used by the packet receiving unit and/or the packet transfer unit.

4. The packet relay device of claim 3, further comprising:

a registration unit configured to register the current location address of the mobile computer into the second memory unit when the packet received from the mobile computer located at the visited site is a registration request packet containing the current location address of the mobile computer which is a packet destined to a mobile computer management device in the home network of the mobile computer.

5. The packet relay device of claim 1, wherein the packet receiving unit also receives another packet in the second format using the private address which is transmitted by the correspondent computer in the home network of the mobile computer, said another packet being transmitted by using a private address of the packet relay device and checks a content of said another packet;

and

the packet transfer unit also transfers said another packet in the first format using the global address, to the mobile computer at the visited site, according to the content of said another packet, said another packet being transferred by using a global address of the mobile computer.

6. he packet relay device of claim 5, wherein:

the packet receiving unit decrypts said another packet received from the correspondent computer using a key corresponding to the correspondent computer, and

the packet transfer unit re-encrypts a decrypted packet using a key corresponding to the mobile computer, encapsulates an encrypted packet by attaching a header having a global address of the packet relay device as a source and a global address of the mobile computer as a destination, and transfers an encapsulated packet to the mobile computer.

7. A mobile computer device capable of carrying out communications while moving over a plurality of inter-connected networks, comprising:

a current location setting unit configured to store an information indicating whether or not the mobile computer device is currently connected to a private address space identical to that of a home network in which a mobile computer management device for managing a current location address of the mobile computer device and transferring a packet destined to the mobile computer device to the current location address is provided;

a relay device information unit configured to set a global address in a global address space of a packet relay device which is provided at a border between the private address space and the global address space and relaying a packet to be exchanged between one computer connected to the private address space and another computer connected to the global address space; and

a transmission unit configured to transmit to the packet relay device at least a registration request packet for a location registration at the home network that is containing the current location address of the mobile computer and destined to the mobile computer management device, by using the global address of the packet relay device stored by the relay device information unit, when the current location setting unit stores the information indicating that the mobile computer device is currently not connected to the private address space.

8. The mobile computer device of claim 7, wherein the transmission unit transmits to the packet relay device every packet that is destined to a correspondent computer in the home network, by encrypying each packet and using the global address stored by the relay device information unit, when the current location setting unit stores the information indicating that the mobile computer device is currently not connected to the private address space.

9. The mobile computer device of claim 7, further comprising:

an automatic acquisition setting unit for setting whether or not an address at a visited site is to be automatically acquired; and

a current location address unit for setting an address acquired by executing a prescribed protocol for having an address allocation as the current location address when the current location setting unit stores the information indicating that the mobile computer device is currently not connected to the private address space and the automatic acquisition setting unit indicates that the address at the visited site is to be automatically acquired.

10. A mobile computer management device provided at a home network of a mobile computer that is capable of carrying out communications while moving over a plurality of inter-connected networks, the mobile computer management device comprising:

a memory unit configured to store in correspondence at least a home address of the mobile computer and a current location address of the mobile computer when the mobile computer is moving outside the home network;

a registration unit configured to decrypt an encrypted packet received from a packet relay device by using a private address of the mobile computer management device and registering the current location address of the mobile computer into the memory unit when a decrypted packet is a registration request packet for a location registration at the home network that is containing the current location address of the mobile computer and transmitted from the mobile computer to the mobile computer management device via the packet relay device, the packet relay device being provided at a border between a private address space by which the home network is managed and a global address space and relaying a packet to be exchanged between one computer connected to the private address space and another computer connected to the global address space; and

a transfer unit configured to transfer a packet destined to the home address of the mobile computer in the home network to the current location address of the mobile computer according to the memory unit.

11. The mobile computer management device of claim 10, further comprising:

a transmission unit for transmitting to the packet relay device a registration reply packet which is corresponding to the registration request packet and destined to the mobile computer, by encrypting the registration reply packet.

12. The mobile computer management device of claim 10, wherein when one packet transmitted to the home address of the mobile computer which is moving outside the home network is captured, the transfer unit encapsulates said one packet by attaching a header having a private address of the mobile computer management device as a source and the current location address of the mobile computer as a destination, and transmits an encapsulated packet to the packet relay device by encrypting the encapsulated packet.

13. A packet relay method at a packet relay device in a network system supporting a mobile computer that is capable of carrying out communications while moving over a plurality of interconnected networks, for relaying packets having an address of the mobile computer device as a destination or source, the method comprising:

receiving a packet in a first format using a global address which is transmitted by the mobile computer for a location registration at a home network from a visited site managed by a global address system which is valid throughout the inter-connected networks, the packet being transmitted by using a global address of the packet relay device, and checking a content of the packet; and

transferring the packet in a second format using a private address, to a correspondent computer in the home network of the mobile computer managed by a private address system which is valid only within the home network, according to the content of the packet, the packet being transferred by using a private address of the correspondent computer which is different from the packet relay device identified by the global address of the packet received by the receiving step.

14. A packet transmission method in a mobile computer device capable of carrying out communications while moving over a plurality of inter-connected networks, the method comprising:

(a) storing an information indicating whether or not the mobile computer device is currently connected to a private address space identical to that of a home network in which a mobile computer management device for managing a current location address of the mobile computer device and transferring a packet destined to the mobile computer device to the current location address is provided;

(b) storing a global address in a global address space of a packet relay device which is provided at a border between the private address space and the global address space and relaying a packet to be exchanged between one computer connected to the private address space and another computer connected to the global address space; and

(c) transmitting to the packet relay device at least a registration request packet for a location registration at the home network that is containing the current location address of the mobile computer and destined to the mobile computer management device, by using the global address of the packet relay device stored by the step (b), when the step (a) stores the information indicating that the mobile computer device is currently not connected to the private address space.

15. A packet transfer method in a mobile computer management device provided at a home network of a mobile computer that is capable of carrying out communications while moving over a plurality of inter-connected networks, the method comprising:

storing in correspondence at least a home address of the mobile computer and a current location address of the mobile computer when the mobile computer is moving outside the home network, in a memory;

decrypting an encrypted packet received from a packet relay device by using a private address of the mobile computer management device and registering the current location address of the mobile computer into the memory when a decrypted packet is a registration request packet for a location registration at the home network that is containing the current location address of the mobile computer and transmitted from the mobile computer to the mobile computer management device via the packet relay device, the packet relay device being provided at a border between a private address space by which the home network is managed and a global address space and relaying a packet to be exchanged between one computer connected to the private address space and another computer connected to the global address space; and

transferring a packet destined to the home address of the mobile computer in the home network to the current location address of the mobile computer according to the memory.

16. A computer usable medium having computer readable program codes embodied therein for causing a computer to function as a packet relay device in a network system supporting a mobile computer that is capable of carrying out communications while moving over a plurality of interconnected networks, for relaying packets having an address of the mobile computer device as a destination or source, the computer readable program codes include:

a first computer readable program code for causing said computer to receive a packet in a first format using a global address which is transmitted by the mobile computer for a location registration at a home network from a visited site managed by a global address system which is valid throughout the inter-connected networks, the packet being transmitted by using a global address of the packet relay device, and check a content of the packet; and

a second computer readable program code for causing said computer to transfer the packet in a second format using a private address, to a correspondent computer in the home network of the mobile computer managed by a private address system which is valid only within the home network, according to the content of the packet, the packet being transferred by using a private address of the correspondent computer which is different from the packet relay device identified by the global address of the packet received by the first computer readable program code.

17. A computer usable medium having computer readable program codes embodied therein for causing a computer to function as a mobile computer device capable of carrying out communications while moving over a plurality of inter-connected networks, the computer readable program codes include:

a first computer readable program code for causing said computer to store an information indicating whether or not the mobile computer device is currently connected to a private address space identical to that of a home network in which a mobile computer management device for managing a current location address of the mobile computer device and transferring a packet destined to the mobile computer device to the current location address is provided;

a second computer readable program code for causing said computer to store a global address in a global address space of a packet relay device which is provided at a border between the private address space and the global address space and relaying a packet to be exchanged between one computer connected to the private address space and another computer connected to the global address space; and

a third computer readable program code for causing said computer to transmit to the packet relay device at least a registration request packet for a location registration at the home network that is containing the current location address of the mobile computer and destined to the mobile computer management device, by using the global address of the packet relay device stored by the second computer readable program code means, when the first computer readable program code means stores the information indicating that the mobile computer device is currently not connected to the private address space.

18. A computer usable medium having computer readable program codes embodied therein for causing a computer to function as a mobile computer management device provided at a home network of a mobile computer that is capable of carrying out communications while moving over a plurality of inter-connected networks, the computer readable program codes include:

a first computer readable program code for causing said computer to store in correspondence at least a home address of the mobile computer and a current location address of the mobile computer when the mobile computer is moving outside the home network, in a memory;

a second computer readable program code for causing said computer to decrypt an encrypted packet received from a packet relay device by using a private address of the mobile computer management device and register the current location address of the mobile computer into the memory when a decrypted packet is a registration request packet for a location registration at the home network that is containing the current location address of the mobile computer and transmitted from the mobile computer to the mobile computer management device via the packet relay device, the packet relay device being provided at a border between a private address space by which the home network is managed and a global address space and relaying a packet to be exchanged between one computer connected to the private address space and another computer connected to the global address space; and

a third computer readable program code for causing said computer to transfer a packet destined to the home address of the mobile computer in the home network to the current location address of the mobile computer according to the memory.