Inter-proxy communication protocol for mobile IP

• US 20040114559A1
• Filed: 12/16/2002
• Published: 06/17/2004
• Est. Priority Date: 12/16/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Wang, Huizhao
• Granted Patent: US 7,457,289 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• 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 88/182 Network node acting on behalf of an other network entity, e.g. proxy

Abstract

Methods and apparatus for ascertaining configuration information for a node are disclosed. A first access point sends an inter-proxy request message to one or more additional access points, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested. The first access point then receives an inter-proxy reply message from a second one of the additional access points, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information. In this manner, the Access Points support mobility for a node that does not support Mobile IP.

Claims

1. In a first access point, a method of supporting mobility for a node that does not support Mobile IP, comprising:

sending an inter-proxy request message to an IP address identifying an inter-proxy multicast group, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested; and

receiving an inter-proxy reply message from a second access point, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.

2. The method as recited in claim 1, wherein the inter-proxy request message includes a MAC address identifying the node or an IP address identifying the node.

3. The method as recited in claim 1, wherein the inter-proxy request message includes a sequence number and the inter-proxy reply message includes the sequence number.

4. The method as recited in claim 1, wherein the inter-proxy request message includes a type that identifies the inter-proxy request message as an inter-proxy message and the inter-proxy reply message includes the type that identifies the inter-proxy reply message as an inter-proxy message.

5. The method as recited in claim 4, wherein the inter-proxy request message includes an opcode identifying the inter-proxy request message as a query, and the inter-proxy reply message includes an opcode identifying the inter-proxy reply message as a response.

6. The method as recited in claim 1, wherein the inter-proxy request message includes an IP address of the first access point and the inter-proxy reply message includes an IP address of the second access point.

7. The method as recited in claim 6, wherein the inter-proxy request message further includes a MAC address of the first access point and the inter-proxy reply message further includes a MAC address of the second access point.

8. The method as recited in claim 1, wherein the inter-proxy request message and the inter-proxy reply message are composed to include a hash value generated using a key shared by the first access point and the second access point.

9. The method as recited in claim 1, wherein the inter-proxy request message and the inter-proxy reply message are composed to include a hash value generated using a key shared by members of the inter-proxy multicast group.

10. The method as recited in claim 1, wherein the inter-proxy request message is an IP UDP message, and the inter-proxy reply message is either a UDP or TCP message.

11. The method as recited in claim 1, wherein the IP configuration information comprises an IP address of the node and a Home Agent address identifying a Home Agent.

12. The method as recited in claim 11, wherein the IP configuration information further comprises a netmask.

13. The method as recited in claim 11, wherein the IP configuration information further comprises a care-of address.

14. The method as recited in claim 13, wherein the care-of address is the Home Agent address.

15. The method as recited in claim 1, wherein sending the inter-proxy request message is performed when the node roams to the first access point.

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

storing the IP configuration information in a client history table such that the IP configuration information is associated with the node.

17. In a second access point, a method of supporting mobility for a node that does not support Mobile IP, comprising:

receiving an inter-proxy request message from a first access point, the inter-proxy request message being addressed to an inter-proxy multicast group address and indicating that IP configuration information for the node is requested;

sending an inter-proxy reply message to the first access point, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.

18. The method as recited in claim 17, further comprising:

searching a client history table for IP configuration information for the node;

wherein sending an inter-proxy reply message is performed when IP configuration information for the node is located in the client history table.

19. The method as recited in claim 18, wherein the IP configuration information comprises an IP address for the node and a Home Agent address.

20. The method as recited in claim 17, the method further comprising:

obtaining the IP configuration information for the node from a client history table storing IP configuration information for a plurality of nodes.

21. The method as recited in claim 17, wherein the IP configuration information comprises an IP address for the node and a Home Agent address.

22. In a first access point, a method of supporting mobility for a node that does not support Mobile IP, comprising:

sending an inter-proxy request message to one or more additional access points, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested; and

receiving an inter-proxy reply message from a second one of the additional access points, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.

23. A computer-readable medium storing thereon computer-readable instrucgtions for supporting mobility for a node that does not support Mobile IP in a first access point, comprising:

instructions for sending an inter-proxy request message to one or more additional access points, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested; and

instructions for receiving an inter-proxy reply message from a second one of the additional access points, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.

24. A first access point supporting mobility for a node that does not support Mobile IP, comprising:

means for sending an inter-proxy request message to one or more additional access points, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested; and

means for receiving an inter-proxy reply message from a second one of the additional access points, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.

25. A first access point supporting mobility for a node that does not support Mobile IP, comprising:

a processor; and

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

sending an inter-proxy request message to one or more additional access points, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested; and

receiving an inter-proxy reply message from a second one of the additional access points, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.

26. A computer-readable medium storing thereon computer-readable instructions for supporting mobility for a node that does not support Mobile IP in a first access point, comprising:

instructions for sending an inter-proxy request message to an IP address identifying an inter-proxy multicast group, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested; and

instructions for receiving an inter-proxy reply message from a second access point, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.

27. A first access point supporting mobility for a node that does not support Mobile IP, comprising:

means for sending an inter-proxy request message to an IP address identifying an inter-proxy multicast group, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested; and

means for receiving an inter-proxy reply message from a second access point, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.

28. A first access point supporting mobility for a node that does not support Mobile IP, comprising:

a processor; and

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

sending an inter-proxy request message to an IP address identifying an inter-proxy multicast group, the inter-proxy request message identifying the node and indicating that IP configuration information for the node is requested; and

receiving an inter-proxy reply message from a second access point, the inter-proxy reply message including the IP configuration information, thereby enabling the first access point to send a registration request on behalf of the node using the IP configuration information.