Support mobile device in asymmetric link environment

• US 7,295,551 B1
• Filed: 12/28/2000
• Issued: 11/13/2007
• Est. Priority Date: 12/28/2000
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Leung, Kent K., Patel, Alpesh Sanatbhai
• Primary Examiner(s): MEHRPOUR, NAGHMEH
• Application Number:
  US09/752,884
• Time in Patent Office: 2,511 Days
• Field of Search: 455/12.1, 709/223, 709/225, 709/220, 709/230, 709/245, 709/227, 709/208, 709217-218, 709200-201, 709/238, 709/228, 370/389, 370/399
• US Class Current: 370/389
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

Methods and apparatus for registering a mobile device such as a mobile node or mobile router with a Home Agent in an asymmetric link environment. A Foreign Agent associates each of one or more interfaces of the Foreign Agent with a different care-of address. An agent advertisement including the care-of address for the one or more interfaces of the Foreign Agent is then sent via one or more uplinks. A registration request is received via a downlink router. The registration request identifies a care-of address associated with one of the one or more interfaces of the Foreign Agent. One of the interfaces identified by the care-of address is ascertained, thereby identifying the interface to which the mobile device has roamed. The registration request is forwarded to the Home Agent. A registration reply is received from the Home Agent. The registration reply is then forwarded to the mobile device via the ascertained interface.

Claims

1. In a Foreign Agent, a method of registering a mobile device with a Home Agent in an asymmetric link environment, the method comprising:

associating each one of a plurality of interfaces of the Foreign Agent with a different care-of address such each of the plurality of interfaces is mapped to a different care-of address;

sending at least one agent advertisement including the care-of address for each of the plurality of interfaces of the Foreign Agent via one or more uplinks;

receiving a registration request forwarded via a downlink router, the registration request identifying a care-of address associated with only one of the plurality of interfaces of the Foreign Agent;

ascertaining the one of the plurality of interfaces identified by the care-of address in the registration request, thereby identifying the interface to which the mobile device has roamed;

forwarding the registration request to the Home Agent;

receiving a registration reply from the Home Agent; and

forwarding the registration reply to the mobile device via the ascertained interface.

2. The method as recited in claim 1, wherein the registration request further includes an extension including a source MAC address of the mobile device.

3. The method as recited in claim 2, wherein the registration reply includes a destination MAC address that is the source MAC address of the mobile device.

4. The method as recited in claim 1, wherein the registration request includes a destination IP address field having a value of the care-of address from the agent advertisement.

5. The method as recited in claim 1, further comprising:

entering the registration request in a pending registration request list; and

updating the pending registration request list when the registration reply is received from the Home Agent.

6. The method as recited in claim 1, further comprising:

marking the registration request as having been received on the interface advertising the care-of address.

7. The method as recited in claim 6, wherein marking the registration request as having been received on the interface advertising the care-of address comprises:

updating a pending registration request list to indicate that the registration request has been received on the interface advertising the care-of address.

8. The method as recited in claim 1, wherein the registration reply includes a destination MAC address that is a broadcast address.

9. The method as recited in claim 1, wherein the registration reply includes a destination MAC address that is a multicast address.

10. The method as recited in claim 1, wherein each of the plurality of interfaces has been assigned a different care-of address.

20. The method as recited in claim 1, wherein each of the plurality of interfaces has been assigned a different care-of address.

11. In a downlink router, a method of forwarding a Mobile IP registration request in an asymmetric link environment, the method comprising:

receiving a registration request composed and sent by a mobile device, the registration request identifying a care-of address associated with only one of a plurality of interfaces of a Foreign Agent, wherein each of the plurality of interfaces of the Foreign Agent has a different care-of address;

forwarding the registration request to the Foreign Agent, thereby enabling the Foreign Agent to process the registration request and forward a registration reply to the mobile device via the interface.

12. The method as recited in claim 11, wherein the mobile device includes a router.

13. The method as recited in claim 11, wherein the mobile device is a mobile node supporting Mobile IP.

14. The method as recited in claim 11, wherein the registration request includes a time to live field having a value that is greater than one.

15. The method as recited in claim 11, wherein the downlink router is a Foreign Agent.

16. The method as recited in claim 11, wherein the asymmetric link environment includes one or more satellites.

17. The method as recited in claim 11, wherein the registration request further includes an extension including a source MAC address of the mobile device.

18. The method as recited in claim 11, wherein the registration request includes a destination IP address field having a value of the care-of address.

19. The method as recited in claim 11, wherein the registration request is sent using a destination MAC address that is a broadcast or multicast MAC address.

21. A Foreign Agent that supports Mobile IP, the Foreign Agent being capable of registering a mobile device with a Home Agent in an asymmetric link environment, the Foreign Agent comprising:

a processor; and

a memory, at least one of the processor or the memory being adapted for;

associating each one of a plurality of interfaces of the Foreign Agent with a different care-of address such that each of the plurality of interfaces is mapped to a different care-of address;

sending at least one agent advertisement including the care-of address for each of the plurality of interfaces of the Foreign Agent via one or more uplinks;

receiving a registration request forwarded via a downlink router, the registration request identifying a care-of address associated with only one of the plurality of interfaces of the Foreign Agent;

ascertaining the one of the plurality of interfaces identified by the care-of address in the registration request, thereby identifying the interface to which the mobile device has roamed;

forwarding the registration request to the Home Agent;

receiving a registration reply from the Home Agent; and

forwarding the registration reply to the mobile device via the ascertained interface.

22. The Foreign Agent as recited in claim 21, wherein the mobile device is a mobile router supporting Mobile IP.

23. The Foreign Agent as recited in claim 21, wherein the mobile device is a mobile node supporting Mobile IP.

24. The Foreign Agent as recited in claim 21, wherein the downlink router is a Foreign Agent.

25. The Foreign Agent as recited in claim 21, wherein the asymmetric link environment includes one or more satellites.

26. A computer-readable medium, the computer-readable medium being adapted for enabling a Foreign Agent that supports Mobile IP to register a mobile device with a Home Agent in an asymmetric link environment, comprising:

instructions for associating each one of a plurality of interfaces of the Foreign Agent with a different care-of address such that each of the plurality of interfaces is mapped to a different care-of address;

instructions for sending at least one agent advertisement including the care-of address for each of the plurality of interfaces of the Foreign Agent via one or more uplinks;

instructions for receiving a registration request forwarded via a downlink router, the registration request identifying a care-of address associated with only one of the plurality of interfaces of the Foreign Agent;

instructions for ascertaining the one of the plurality of interfaces identified by the care-of address in the registration request, thereby identifying the interface to which the mobile devices has roamed;

instructions for forwarding the registration request to the Home Agent;

instructions for receiving a registration reply from the Home Agent; and

instructions for forwarding the registration reply to the mobile device via the ascertained interface.

27. A Foreign Agent that supports Mobile IP, the Foreign Agent being capable of registering a mobile device with a Home Agent in an asymmetric link environment, the Foreign Agent comprising:

means for associating each one of a plurality of interfaces of the Foreign Agent with a different care-of address such that each of the plurality of interfaces is mapped to a different care-of address;

means for sending at least one agent advertisement including the care-of address for each of the plurality of interfaces of the Foreign Agent via one or more uplinks;

means for receiving a registration request forwarded via a downlink router, the registration request identifying a care-of address associated with only one of the plurality of interfaces of the Foreign Agent;

means for ascertaining the one of the plurality of interfaces identified by the care-of address in the registration request, thereby identifying the interface to which the mobile device has roamed;

means for forwarding the registration request to the Home Agent;

means for receiving a registration reply from the Home Agent; and

means for forwarding the registration reply to the mobile device via the ascertained interface.