Virtual distributed home agent protocol

• US 6,430,698 B1
• Filed: 06/02/1999
• Issued: 08/06/2002
• Est. Priority Date: 10/05/1998
• Status: Expired due to Term

• Current Assignee: Blackberry Limited
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Coffin, Russel, Akhtar, Haseeb, Khalil, Mohamed, Qaddoura, Emad, Becker, Carey
• Primary Examiner(s): Ray, Gopal C.
• Application Number:
  US09/324,322
• Time in Patent Office: 1,161 Days
• Field of Search: 714/4, 710/105, 709/238, 709/201, 379/219, 379/90.01, 725/113, 455/6.3, 455/3.2, 455/418, 455/517, 455/426, 707/104, 370/352, 370/464, 370/310, 370/901, 370/469, 370/912, 370/400
• US Class Current: 714/4.1
• CPC Class Codes: H04W 8/065 involving selection of the user mobility server
• CPC Class Codes: H04W 8/12 between location registers or mobility servers
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

A computer protocol that manages and provides efficient communications and utilization of resources between a mobile computer system or device and other systems and devices. Each home agent maintains a home agent list containing information about each of the home agents coupled to the home link. A designated home agent on behalf of the home agents for a virtual home agent is used to send and broadcast home agent advertisement, to receive and process a request from a mobile node, to process and send a reply to the mobile node. Synchronization mechanisms or tools, such as home agent priority or floating token method, are provided for proper operation of a Virtual Distribution Home Agent Protocol (VDHAP). These mechanisms or tools are used to fairly distribute loads from the mobile node among the home agents within the virtual home agent.

Claims

1. A virtual distributed home agent protocol method for managing and providing efficient communications and utilization of resources between a mobile node and home agents coupled to a home link, comprising the steps of:

encapsulating and integrating communications of the home agents into a single virtual home agent by selecting a designated home agent to communicate on behalf of the home agents to the mobile node;

communicating between the mobile node and the single virtual home agent; and

performing processes based on the communication between the mobile node and the single virtual home agent.

2. The virtual distributed home agent protocol method according to claim 1 wherein the selecting step further comprises the step of:

selecting the designated home agent based on a home agent priority policy.

3. The virtual distributed home agent protocol method according to claim 2 wherein the home agent priority policy is based on a policy of busyness of the home agents.

4. The virtual distributed home agent protocol method according to claim 1 wherein the selecting step further comprises the step of:

selecting the designated home agent based on a floating token policy.

5. The virtual distributed home agent protocol method according to claim 4 wherein the floating token policy is based on assigning the designated home agent to be a token holder and switching the token holder to be one of the other home agents based on load factors.

6. The virtual distributed home agent protocol method according to claim 1 wherein the communicating step further comprises the step of:

communicating between the mobile node and a designated home agent that acts for the virtual home agent and communicates on behalf of the other home agents.

7. The virtual distributed home agent protocol method according to claim 6 wherein the step of communicating between the mobile node and a designated home agent further comprises the step of:

communicating a home agent discovery request from the mobile node to the virtual home agent.

8. The virtual distributed home agent protocol method according to claim 6 wherein the step of communicating between the mobile node and a designated home agent further comprises the step of:

communicating a home agent discovery reply from the virtual home agent to the mobile node.

9. The virtual distributed home agent protocol method according to claim 9 wherein the communicating step further comprises the step of:

communicating a home agent advertisement from the virtual home agent to the mobile node.

10. The virtual distributed home agent protocol method according to claim 9 wherein the step of communicating a home agent advertisement further comprises the step of:

communicating the home agent advertisement from a designated home agent that acts for the virtual home agent and communicates on behalf of the other home agents to the mobile node.

11. A virtual distributed home agent protocol method for managing and providing efficient communications and utilization of resources between a mobile node and home agents coupled to a home link, comprising the steps of:

encapsulating and integrating communications of the home agents into a single virtual home agent, by;

having each of the home agents maintain a home agent list containing information about each of the home agents coupled to the home link wherein the information includes at least an Internet protocol address of each of the other home agents, remaining lifetime of the home agents on the home agents list, and status of each of the home agents, and

using heartbeat messages to communicate the information between each of the home agents;

communicating between the mobile node and the single virtual home agent; and

performing processes based on the communication between the mobile node and the single virtual home agent.

12. The virtual distributed home agent protocol method according to claim 11 wherein the using heart beat messages step further comprises the step of:

determining a home agent to be a failed home agent when the heartbeat message has not been sensed from the home agent.

13. The virtual distributed home agent protocol method according to claim 12 wherein the determining step further comprises the steps of:

designating at least one home agent as a failure recovery agent,

using the failure recovery agent to recover information relating to the failed home agent, and

wherein the method further comprises the step of;

having the failure recovery agent reassign a new home agent to take over operations of the failed home agent.

14. The virtual distributed home, agent protocol method according to claim 13 wherein the using the failure recovery agent step further comprises the steps of:

designating multiple home agents as failure recovery agents, and

using one of the failure recovery agents to obtain recovery information related to the failed home agent from the other failure recovery agents.

15. The virtual distributed home agent protocol method according to claim 13 wherein the using the failure recovery agent step further comprises the steps of:

designating only one home agent as a failure recovery agent,

using the failure recovery agent to obtain recovery information related to the failed home agent from the other home agents, and

wherein the method further comprises the step of;

having the failure recovery agent reassign a new home agent to take over operations of the failed home agent.

16. A virtual distributed home agent protocol method for managing and providing efficient communications and utilization of resources between a mobile node and home agents coupled to a home link, comprising the steps of:

encapsulating and integrating communications of the home agents into a single virtual home agent;

communicating between the mobile node and the single virtual home agent; and

performing processes based on the communication between the mobile node and the single virtual home agent by using a designated home agent on behalf of the home agents for the virtual home agent to receive and process a request from the mobile node.

17. The virtual distributed home agent protocol method according to claim 16 wherein the performing processes step further comprises the step of:

using a designated home agent on behalf of the home agents for the virtual home agent to process and send a reply to the mobile node.

18. The virtual distributed home agent protocol method according to claim 16 wherein the performing processes step further comprises the step of:

fairly distributing loads from the mobile node among the home agents within the virtual home agent.