Communication method, mobile agent device, and home agent device

• US 8,717,941 B2
• Filed: 11/16/2006
• Issued: 05/06/2014
• Est. Priority Date: 11/16/2005
• Status: Active Grant

• Current Assignee: NTTPC Communications, Inc.
• Original Assignee: NTTPC Communications, Inc.
• Inventors: Hata, Hiroaki, Futana, Nobuaki, Ishikawa, Hajime
• Primary Examiner(s): Mesfin, Yemane
• Assistant Examiner(s): DAVENPORT, MON CHERI S
• Application Number:
  US12/093,962
• Publication Number:
  US 20090092095A1
• Time in Patent Office: 2,728 Days
• Field of Search: 370/229, 370/231, 370/235, 370/252, 370/254, 370/255, 370/310, 370/328, 370/338, 370/389, 370/400, 370/401, 370/463, 370/468
• US Class Current: 370/255
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 61/59 using proxies for addressing
• 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 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 88/182 Network node acting on behalf of an other network entity, e.g. proxy

Abstract

In a communication system including a MN, a MFA connected to the MN, and a HA connected to a home network of the MN, the HA holds a layer 3 address of the HA and a source layer 3 address of a registration request by associating them with each other. The MFA transmits a layer 2 frame from the MN to the HA by encapsulating it. The HA decapsulates the frame to transmit it to the home network. When the HA receives a layer 2 frame from the home network, the HA checks that the destination layer 3 address is registered, and encapsulates the layer 2 frame to transmit it to a source layer 3 address of the registration request that is registered being associated with the destination layer 3 address. The MFA decapsulate the encapsulated layer 2 frame to transmit the layer 2 frame to the MN.

Claims

1. A communication method in a communication system including a user terminal, a mobile agent apparatus connected to the user terminal, and a home agent apparatus connected to a home network of the user terminal, the communication method comprising:

storing, in a storing unit of the home agent apparatus, a Media Access Control (MAC) address of the mobile agent apparatus and a first layer 3 address of the user terminal corresponding to the MAC address of the mobile agent apparatus, in a table in association with each other, and storing a second MAC address of a second mobile agent apparatus and a second layer 3 address of a second home agent apparatus corresponding to the second MAC address of the second mobile agent apparatus, in the table in association with each other, the mobile agent apparatus and the second mobile agent apparatus being different;

receiving, by the home agent apparatus, a registration request that includes the MAC address of the mobile agent apparatus from the mobile agent apparatus, obtaining, by the home agent apparatus from the table in the storing unit, the first layer 3 address of the user terminal that corresponds to the MAC address included in the registration request, registering, by the home agent apparatus, the first layer 3 address of the user terminal, a source layer 3 address of the registration request, and a source port number of the registration request in an address correspondence table by associating them with each other, and holding, by the mobile agent apparatus, the first layer 3 address of the user terminal;

when the user terminal transmits a packet to a communication partner terminal, receiving, by the mobile agent apparatus, a layer 2 frame from the user terminal, and if a source layer 3 address in a layer 3 header in the layer 2 frame is registered, encapsulating, by the mobile agent apparatus, the received layer 2 frame to transmit the layer 2 frame to the home agent apparatus;

decapsulating, by the home agent apparatus, the encapsulated layer 2 frame to extract the layer 2 frame, and transmitting, by the home agent apparatus, the layer 2 frame to the home network, and transferring, by a router that accommodates the home network, a packet to the communication partner terminal;

when the communication partner terminal transmits a packet to the user terminal, receiving, by the home agent apparatus, a layer 2 frame from the home network, checking, by the home agent apparatus, that a destination layer 3 address in a layer 3 header in the layer 2 frame is registered in the address correspondence table, and encapsulating, by the home agent apparatus, the layer 2 frame to transmit the layer 2 frame to the source layer 3 address and the source port number of the registration request that are registered in the address correspondence table with the destination layer 3 address;

receiving, by the mobile agent apparatus, the encapsulated layer 2 frame, decapsulating, by the mobile agent apparatus, the encapsulated layer 2 frame to extract the layer 2 frame, and transmitting, by the mobile agent apparatus, the layer 2 frame to the user terminal; and

when the home agent apparatus receives a registration request, including the second MAC address, transmitted from the second mobile agent apparatus, referring, by the home agent apparatus, to the storing unit to transmit a redirect response including the second layer 3 address of the second home agent apparatus to the second mobile agent apparatus.

9. The communication method as claimed in claim 1, wherein the first layer 3 address of the user terminal and the second layer 3 address of the second home agent apparatus are both IP addresses.

10. The communication method as claimed in claim 1, further comprising:

transmitting, by the home agent apparatus to the mobile agent apparatus, the first layer 3 address of the user terminal that corresponds to the MAC address included in the registration request; and

receiving, by the mobile agent apparatus, the first layer 3 address of the user terminal, wherein

the holding, by the mobile agent apparatus, holds the first layer 3 address of the user terminal after the receiving receives the first layer 3 address of the user terminal.

2. A communication method in a communication system including a user terminal, a mobile agent apparatus connected to the user terminal, and a home agent apparatus connected to a home network of the user terminal, the method comprising:

storing, in a storing unit of the home agent apparatus, a Media Access Control (MAC) address of the mobile agent apparatus and a first layer 3 address of the user terminal corresponding to the MAC address of the mobile agent apparatus, in a table in association with each other, and storing a second MAC address of a second mobile agent apparatus and a second layer 3 address of a second home agent apparatus corresponding to the second MAC address of the second mobile agent apparatus, in the table in association with each other, the mobile agent apparatus and the second mobile agent apparatus being different;

receiving, by the home agent apparatus, a registration request that includes the MAC address of the mobile agent apparatus from the mobile agent apparatus, obtaining, by the home agent apparatus from the table in the storing unit, the first layer 3 address of the user terminal that corresponds to the MAC address included in the registration request, registering, by the home agent apparatus, the first layer 3 address of the user terminal, a source layer 3 address of the registration request, and a source port number of the registration request in an address correspondence table by associating them with each other, and holding, by the mobile agent apparatus, the first layer 3 address of the user terminal;

when the user terminal transmits a packet to a communication partner terminal, receiving, by the mobile agent apparatus, a layer 2 frame from the user terminal, and if a source layer 3 address in a layer 3 header in the layer 2 frame is registered, encapsulating, by the mobile agent apparatus, by the mobile agent apparatus, a packet obtained by deleting a layer 2 header of the received layer 2 frame to transmit the packet to the home agent apparatus;

decapsulating, by the home agent apparatus, the encapsulated packet to extract the packet, and transferring, by the home agent apparatus, the packet based on a layer 3 header;

when the communication partner terminal transmits a packet to the user terminal, receiving, by the home agent apparatus, the packet, checking, by the home agent apparatus, that a destination layer 3 address in a layer 3 header of the packet is registered in the address correspondence table, and encapsulating, by the home agent apparatus, the packet to transmit the packet to the source layer 3 address and the source port number of the registration request that are registered in the address correspondence table with the destination layer 3 address;

receiving, by the mobile agent apparatus, the encapsulated packet, decapsulating, by the mobile agent apparatus, the encapsulated packet to extract the packet, and transmitting, by the mobile agent apparatus, the packet to the user terminal; and

when the home agent apparatus receives a registration request, including the second MAC address, transmitted from the second mobile agent apparatus, referring, by the home agent apparatus, to the storing unit to transmit a redirect response including the second layer 3 address of the second home agent apparatus to the second mobile agent apparatus.

3. The communication method as claimed in claim 2, further comprising:

when the mobile agent apparatus receives an Address Resolution Protocol request from the user terminal, if the mobile agent apparatus checks that a source layer 3 address of the Address Resolution Protocol request is registered in the mobile agent apparatus, transmitting, by the mobile agent apparatus, an own Media Access Control address to the user terminal as a response to the Address Resolution Protocol request.

4. A mobile agent apparatus used in a communication system including a user terminal, the mobile agent apparatus connected to the user terminal, and a home agent apparatus connected to a home network of the user terminal, the mobile agent apparatus comprising:

a registration request unit configured to transmit a registration request that includes a Media Access Control (MAC) address of the mobile agent apparatus to the home agent apparatus;

a response reception unit configured to receive a registration response to the registration request from the home agent apparatus, to store, in a storing unit, a layer 3 address of the user terminal corresponding to the MAC address of the mobile agent apparatus and included in the registration response from the home agent apparatus, and to transmit a registration response acknowledgement to the home agent apparatus;

a unit configured to receive a layer 2 frame from the user terminal, and if a source layer 3 address in a layer 3 header in the layer 2 frame is registered in the storing unit, to encapsulate the received layer 2 frame, and to transmit the layer 2 frame to the home agent apparatus; and

a unit configured to receive an encapsulated layer 2 frame, to decapsulate the encapsulated layer 2 frame to extract a layer 2 frame, and to transmit the layer 2 frame to the user terminal,

when the home agent apparatus is not proper for the mobile agent apparatus, the response reception unit receives, from the home agent apparatus, a redirect response including a layer 3 address of a proper home agent apparatus so that the registration request unit transmits a registration request to the proper home agent apparatus.

5. A mobile agent apparatus used in a communication system including a user terminal, the mobile agent apparatus connected to the user terminal, and a home agent apparatus connected to a home network of the user terminal, the mobile agent apparatus comprising:

a registration request unit configured to transmit a registration request that includes a Media Access Control (MAC) address of the mobile agent apparatus to the home agent apparatus;

a response reception unit configured to receive a registration response to the registration request from the home agent apparatus, to store, in a storing unit, a layer 3 address of the user terminal corresponding to the MAC address of the mobile agent apparatus and included in the registration response from the home agent apparatus, and to transmit a registration response acknowledgement to the home agent apparatus;

a unit configured to receive a layer 2 frame from the user terminal, and if a source layer 3 address in a layer 3 header in the layer 2 frame is registered in the storing unit, to encapsulate a packet obtained by deleting a layer 2 header of the received layer 2 frame to transmit the packet to the home agent apparatus; and

a unit configured to receive an encapsulated packet from the home agent apparatus, to decapsulate the encapsulated packet to extract a packet, and to transmit the packet to the user terminal,

when the home agent apparatus is not proper for the mobile agent apparatus, the response reception unit receives, from the home agent apparatus, a redirect response including a layer 3 address of a proper home agent apparatus so that the registration request unit transmits a registration request to the proper home agent apparatus.

6. The mobile agent apparatus as claimed in claim 5, wherein, when the mobile agent apparatus receives an Address Resolution Protocol request from the user terminal, if a source layer 3 address of the Address Resolution Protocol request is registered in the storing unit, and the mobile agent apparatus transmits an own Media Access Control address to the user terminal as a response to the Address Resolution Protocol request.

7. A home agent apparatus in a communication system including a user terminal, a mobile agent apparatus connected to the user terminal, and the home agent apparatus connected to a home network of the user terminal, the home agent apparatus comprising:

a storing unit configured to store a Media Access Control (MAC) address of the mobile agent apparatus and a first layer 3 address of the user terminal corresponding to the MAC address of the mobile agent apparatus, in a table in association with each other, and to store a second MAC address of a second mobile agent apparatus and a second layer 3 address of a second home agent apparatus corresponding to the second MAC address of the second mobile agent apparatus, in the table in association with each other, the mobile agent apparatus and the second mobile agent apparatus being different;

a request reception unit configured to receive a registration request that includes the MAC address of the mobile agent apparatus from the mobile agent apparatus, to obtain from the table in the storing unit the first layer 3 address of the user terminal that corresponds to the MAC address included in the registration request, to register the first layer 3 address of the user terminal, a source layer 3 address of the registration request, and a source port number of the registration request in an address correspondence table by associating them with each other;

a unit configured to receive an encapsulated layer 2 frame including a packet addressed to a communication partner terminal from the mobile agent apparatus, to decapsulate the encapsulated layer 2 frame to extract the layer 2 frame, and to transmit the layer 2 frame to a router in the home network;

a unit configured to receive a layer 2 frame including a packet from the home network, and, if a destination layer 3 address in a layer 3 header in the layer 2 frame is registered in the address correspondence table, to encapsulate the layer 2 frame to transmit the layer 2 frame to the source layer 3 address and the source port number of the registration request that are registered in the address correspondence table with the destination layer 3 address; and

a unit configured to, when the request reception unit receives a registration request, including the second MAC address, transmitted from the second mobile agent apparatus, refer to the storing unit to transmit a redirect response including the second layer 3 address of the second home agent apparatus to the second mobile agent apparatus.

8. A home agent apparatus in a communication system including a user terminal, a mobile agent apparatus connected to the user terminal, and the home agent apparatus connected to a home network of the user terminal, the home agent apparatus comprising:

a storing unit configured to store a Media Access Control (MAC) address of the mobile agent apparatus and a first layer 3 address of the user terminal corresponding to the MAC address of the mobile agent apparatus, in a table in association with each other, and to store a second MAC address of a second mobile agent apparatus and a second layer 3 address of a second home agent apparatus corresponding to the second MAC address of the second mobile agent apparatus, in the table in association with each other, the mobile agent apparatus and the second mobile agent apparatus being different;

a request reception unit configured to receive a registration request that includes the MAC address of the mobile agent apparatus from the mobile agent apparatus, to obtain from the table in the storing unit the first layer 3 address of the user terminal that corresponds to the MAC address included in the registration request, to register the first layer 3 address of the user terminal, a source layer 3 address of the registration request, and a source port number of the registration request in an address correspondence table by associating them with each other;

a unit configured to decapsulate an encapsulated packet addressed to a communication partner terminal to extract the packet, and to transfer the packet based on a layer 3 header to the communication partner terminal;

a unit configured to check that a destination layer 3 address in a layer 3 header of a received packet is registered in the address correspondence table, and to encapsulate the packet to transmit the packet to the source layer 3 address and the source port number of the registration request that are registered in the address correspondence table with the destination layer 3 address; and

a unit configured to, when the request reception unit receives a registration request, including the second MAC address, transmitted from the second mobile agent apparatus, refer to the storing unit to transmit a redirect response including the second layer 3 address of the second home agent apparatus to the second mobile agent apparatus.