Method for providing home agent geographic redundancy via a service redundancy protocol

• US 8,441,988 B2
• Filed: 07/17/2012
• Issued: 05/14/2013
• Est. Priority Date: 11/23/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Cheever, Greg, Puthiyandyil, Sanil Kumar, Ramankutty, Rajesh
• Primary Examiner(s): Prez-Gutirrez, Rafael
• Assistant Examiner(s): Miah, Liton
• Application Number:
  US13/551,112
• Publication Number:
  US 20120281632A1
• Time in Patent Office: 301 Days
• Field of Search: 370/224, 370/328, 370/338, 370/395.52, 713168-170
• US Class Current: 370/328
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• 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

Methods and systems for providing redundancy in servicing packet data communications within wireless mobile data networks are disclosed. More particularly, the method and system provide a redundant Home Agent with the ability to assume the role of the primary Home Agent in the event of a primary Home Agent network, software, or other failure. The redundancy allows the Home Agent services to remain functional even in the event of a failure of one of the Home Agents in the redundant group, which may be composed of one or more Home Agents. The Home Agents can use a service redundancy protocol which is composed of messages that are sent between the redundant group of Home Agents. The messages allow the Home Agents to, for example, back up call session information, check on the status of one another, and share priority information.

Claims

1. A system for providing communication between Home Agents comprising:

a plurality of Home Agents including a first Home Agent acting as a primary Home Agent and at least one second Home Agent acting as backup Home Agents and communicating with the first Home Agent;

a communication link coupling the first Home Agent and the at least one second Home Agent;

the first Home Agent being able to send at least one Hello Message to the at least one second Home Agent, each of the at least one Hello Message containing system attributes including Home Agent state, priority information, and Border Gateway Protocol (BGP) modifier, wherein the priority information includes a weight assigned to a Home Agent for use in operation and the BGP modifier is an attribute used to determine a Home Agent'"'"'s preference in a routing domain;

the first Home Agent being able to send a Service Checkpoint Message to the at least one second Home Agent which provides information used to perform as the primary Home Agent; and

one of the at least one second Home Agent being able, in response to at least one of the at least one Hello Message and the Service Checkpoint Message, to transition to become the primary Home Agent based on the priority information and the BGP modifier in the at least one Hello Message, wherein the BGP modifier is initially used to determine which one of the at least one second Home Agent should transition to become the primary Home Agent and the priority information is used to further determine the primary Home Agent if more than one Home Agent shares a same BGP modifier value.

2. The system of claim 1, wherein the communication link is a redundancy link.

3. The system of claim 1, wherein the Hello Message and the Service Checkpoint Message are formatted in accordance with a Transfer Control Protocol (TCP) based networking protocol.

4. The system of claim 1, wherein the second Home Agent after transitioning to the primary Home Agent advertises identification information of the first Home Agent.

5. The system of claim 4, wherein the identification information includes IP Pool and loopback interface routes.

6. The system of claim 1, wherein the communication link is an inter-Home-Agent communication channel.

7. The system of claim 1, wherein the first Home Agent and the at least one second Home Agent share a common loopback service address.

8. A method for providing communication between Home Agents comprising:

sending a Hello Message containing system attributes from a first Home Agent to at least one second Home Agent, wherein the system attributes includes Home Agent state, priority information, and Border Gateway Protocol (BGP) modifier and wherein the priority information includes a weight assigned to a Home Agent for use in operation and the BGP modifier is an attribute used to determine a Home Agent'"'"'s preference in a routing domain;

sending a Service Checkpoint Message from the first Home Agent acting as a primary Home Agent to the at least one second Home Agent acting as backup Home Agents, wherein the Service Checkpoint Message contains information used to perform as the primary Home Agent; and

transitioning, in response to the Hello Message and the Service Checkpoint Message, one of the at least one second Home Agent to become the primary Home Agent based on the priority information and the BGP modifier in the Hello Message, wherein the BGP modifier is initially used to determine which one of the at least one second Home Agent should transition to become the primary Home Agent and the priority information is used to further determine the primary Home Agent if more than one Home Agent shares a same BGP modifier value.

9. The method of claim 8, wherein the communication occurs through a redundancy link.

10. The method of claim 8, further comprising sending the Hello Message and the Service Checkpoint Message using a Transfer Control Protocol (TCP) based networking protocol.

11. The method of claim 8, further comprising advertising identification information of the first Home Agent after the second Home Agent transitions to the primary Home Agent.

12. The method of claim 11, wherein the identification information includes IP Pool and loopback interface routes.

13. The method of claim 8, wherein the communication occurs through an inter-Home-Agent communication channel.

14. The method of claim 8, wherein the first Home Agent and the at least one second Home Agent share a common loopback service address.

15. A computer program product residing on a non-transitory computer-readable medium, the computer program product comprising computer executable instructions which, when executed by one or more processors, cause the one or more processors to perform a method for providing communication between Home Agents, the method comprising:

sending a Hello Message containing system attributes from a first Home Agent to at least one second Home Agent, wherein the system attributes includes Home Agent state, priority information, and Border Gateway Protocol (BGP) modifier and wherein the priority information includes a weight assigned to a Home Agent for use in operation and the BGP modifier is an attribute used to determine a Home Agent'"'"'s preference in a routing domain;

sending a Service Checkpoint Message from the first Home Agent acting as a primary Home Agent to the at least one second Home Agent acting as backup Home Agents, wherein the Service Checkpoint Message contains information used to perform as the primary Home Agent; and

transitioning, in response to the Hello Message and the Service Checkpoint Message, one of the at least one second Home Agent to become the primary Home Agent based on the priority information and the BGP modifier in the Hello Message, wherein the BGP modifier is initially used to determine which one of the at least one second Home Agent should transition to become the primary Home Agent and the priority information is used to further determine the primary Home Agent if more than one Home Agent shares a same BGP modifier value.

16. The computer program product of claim 15, wherein the communication occurs through a redundancy link.

17. The computer program product of claim 15, wherein the method further comprising sending the Hello Message and the Service Checkpoint Message using a Transfer Control Protocol (TCP) based networking protocol.

18. The computer program product of claim 15, wherein the method further comprising advertising identification information of the first Home Agent after the second Home Agent transitions to the primary Home Agent.

19. The computer program product of claim 18, wherein the identification information includes IP Pool and loopback interface routes.

20. The computer program product of claim 15, wherein the communication occurs through an inter-Home-Agent communication channel.