Mobile IP dynamic home address resolution

• US 6,501,746 B1
• Filed: 01/08/1999
• Issued: 12/31/2002
• Est. Priority Date: 01/08/1999
• 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.
• Primary Examiner(s): Nguyen, Steven
• Assistant Examiner(s): Nguyen, Phuongchau Ba
• Application Number:
  US09/227,397
• Time in Patent Office: 1,453 Days
• Field of Search: 370/389, 370/392, 370/400, 370/401, 370/338, 370/466, 455/433, 455/432, 455/435, 455/431
• US Class Current: 370/338
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/50 Address allocation
• 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 8/06 Registration at serving network Location Register, VLR or user mobility server
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: Y10S 370/901 Wide area network

Abstract

Methods and apparatus for assigning an IP address to a mobile node during registration are disclosed. According to one aspect, a registration request is sent by a mobile node. A mobile node ID associated with the mobile node is obtained. A registration request packet is then composed. The registration request packet stores at least a portion of the mobile node ID in the registration request packet. The registration request packet is sent to a Home Agent associated with the mobile node. According to another aspect, a registration request packet is processed by a Home Agent. The Home Agent receives the registration request packet and ascertains whether the mobile node designated by the registration request packet needs an IP address. An IP address is assigned to the mobile node if it is ascertained that the mobile node needs an IP address. A registration reply specifying the IP address assigned to the mobile node is then composed. According to another aspect, a registration reply packet received by a Foreign Agent is processed. The registration reply packet is received from a Home Agent. The registration reply packet specifies a portion of a mobile node ID and an IP address associated with a mobile node. The portion of the mobile node ID and the IP address are obtained from the registration reply packet. A visitor table is updated with a mapping of the mobile node ID to the IP address. The registration reply packet is sent to the mobile node.

Claims

1. In a mobile node having a mobile node ID, a method of sending a registration request, comprising:

composing a registration request packet;

storing at least a portion of the mobile node ID in the registration request packet;

indicating in the registration request packet whether the mobile node has an IP address; and

sending the registration request packet to a Home Agent associated with the mobile node;

wherein the registration request packet has a home address field, and wherein storing the mobile node ID includes storing a portion of the mobile node ID in the home address field of the registration request packet;

wherein the mobile node ID contains a number of bytes greater than that of the home address field.

2. In a mobile node having a mobile node ID, a method of sending a registration request, comprising:

composing a registration request packet;

storing at least a portion of the mobile node ID in the registration request packet;

indicating in the registration request packet whether the mobile node has an IP address; and

sending the registration request packet to a Home Agent associated with the mobile node;

wherein the registration request packet has a home address field, and wherein storing the mobile node ID includes storing the mobile node ID in the home address field of the registration request packet;

wherein the mobile node ID contains a number of bytes less than or equal to that of the home address field.

3. In a mobile node having a mobile node ID, a method of sending a registration request, comprising:

composing a registration request packet;

storing at least a portion of the mobile node ID in the registration request packet;

indicating in the registration request packet whether the mobile node has an IP address; and

sending the registration request packet to a Home Agent associated with the mobile node;

wherein the registration request packet has a mobile node ID extension, and wherein storing the mobile node ID includes storing the mobile node ID in the mobile node ID extension of the registration request packet.

4. The method as recited in claim 3, the registration request packet further including an extension bit and a home address field, wherein storing the mobile node ID further comprises:

storing the mobile node ID in the mobile node ID extension when the mobile node ID has a number of bytes greater than that of the home address field; and

setting the extension bit in a full state when the number of bytes in the mobile node ID is greater than that of the home address field, and otherwise in an empty state.

5. In a Home Agent, a method of processing a registration request packet received from a mobile node, comprising:

receiving the registration request packet from a mobile node;

ascertaining whether the mobile node designated by the registration request packet needs an IP address;

assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

composing a registration reply specifying the IP address assigned to the mobile node;

wherein the registration request packet specifies at least a portion of a mobile node ID associated with the mobile node;

wherein the registration request packet further includes a mobile node ID extension, the at least a portion of the mobile node ID being provided in the mobile node ID extension of the registration request packet.

6. The method as recited in claim 5, further comprising authenticating the mobile node using the mobile node ID provided in the mobile node ID extension.

7. In a Foreign Agent, a method of processing a registration reply packet received from a Home Agent, comprising:

receiving the registration reply packet, the registration reply packet specifying at least a portion of a mobile node ID and an IP address associated with a mobile node;

obtaining the portion of the mobile node ID and the IP address from the registration reply packet;

updating a visitor table with a mapping of the mobile node ID to the IP address associated with the mobile node; and

sending the registration reply packet to the mobile node, wherein the registration reply packet includes a Home Address field, the portion of the mobile node ID being provided in the Home Address field of the registration reply packet, wherein the mobile node ID contains a number of bytes greater than that of the Home Address field.

8. The method as recited in claim 7, wherein the registration reply packet comprises a Home Address ID extension, the IP address being provided in the Home Address ID extension.

9. In a Foreign Agent, a method of processing a registration reply packet received from a Home Agent, comprising:

receiving the registration reply packet, the registration reply packet specifying at least a portion of a mobile node ID and an IP address associated with a mobile node;

obtaining the portion of the mobile node ID and the IP address from the registration reply packet;

updating a visitor table with a mapping of the mobile node ID to the IP address associated with the mobile node; and

sending the registration reply packet to the mobile node;

wherein the registration reply packet includes a Mobile Node ID extension, the portion of the mobile node ID being provided in the Mobile Node ID extension of the registration reply packet.

10. A computer-readable medium storing thereon computer-readable instructions for processing a registration request packet received from a mobile node in a Home Agent, comprising:

instructions for receiving the registration request packet from a mobile node;

instructions for ascertaining whether the mobile node designated by the registration request packet needs an IP address.

11. In a Home Agent, a method of processing a registration request packet received from a mobile node, comprising:

receiving the registration request packet from a mobile node;

ascertaining whether the mobile node designated by the registration request packet needs an IP address;

assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

composing a registration reply specifying the IP address assigned to the mobile node, wherein the registration reply includes a Home Address field and the mobile node has a mobile node ID, wherein composing the registration reply includes storing a portion of the mobile node ID in the Home Address field of the registration reply, wherein the mobile node ID contains a number of bytes greater than that of the Home Address field.

12. In a Home Agent, a method of processing a registration request packet received from a mobile node, comprising:

receiving the registration request packet from a mobile node;

ascertaining whether the mobile node designated by the registration request packet needs an IP address;

assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

composing a registration reply specifying the IP address assigned to the mobile node;

wherein composing the registration reply includes appending an IP address extension to the registration reply, the IP address extension including the IP address assigned to the mobile node.

13. The method as recited in claim 12, wherein composing the registration reply further comprises appending a mobile node ID extension to the registration reply, the mobile node ID extension including a mobile node ID associated with the mobile node.

14. The method as recited in claim 13, wherein the registration request packet includes a mobile node ID extension including the mobile node ID, wherein composing the registration reply further comprises obtaining the mobile node ID from the mobile node ID extension of the registration request packet.

15. The method as recited in claim 14, wherein the registration request packet further includes an extension bit, the extension bit indicating that the mobile node ID is provided in the mobile node ID extension when in a first state, and indicating that the mobile node ID is provided in a Home Address field of the registration request packet when in a second state, wherein obtaining the mobile node ID from the mobile node ID extension is performed when the extension bit is in the first state.

16. The method as recited in claim 12, wherein the registration request packet includes an ID indicator, the ID indicator indicating that the mobile node has an IP address when the ID indicator is in a first state, and otherwise indicating that the mobile node does not have an IP address, wherein ascertaining comprises determining whether the ID indicator is in the first state.

17. The method as recited in claim 16, wherein the ID indicator is a reserved bit of the registration request packet.

18. The method as recited in claim 12, wherein ascertaining comprises determining from a mobile host table whether the mobile node has an IP address, the mobile host table having a list of mobile nodes that the Home Agent supports, the list of mobile nodes being associated with corresponding IP addresses.

19. The method as recited in claim 12, wherein assigning the IP address to the mobile node comprises obtaining the IP address associated with the mobile node from a mobility binding table, the mobility binding table having a list that maps mobile nodes that have registered with the Home Agent with corresponding IP addresses and care-of addresses.

20. The method as recited in claim 12, wherein assigning the IP address to the mobile node comprises obtaining an IP address from an address pool associated with the Home Agent.

21. The method as recited in claim 20, further comprising de-allocating the IP address such that the IP address is provided in the address pool associated with the Home Agent.

22. The method as recited in claim 12, wherein the registration request packet specifies at least a portion of a mobile node ID associated with the mobile node.

23. The method as recited in claim 22, further comprising updating a mobility binding table to associate the IP address assigned to the mobile node with the mobile node ID.

24. The method as recited in claim 22, wherein the registration request packet further comprises a Home Address field, the portion of the mobile node ID being provided in the Home Address field of the registration request packet.

25. The method as recited in claim 24, further comprising authenticating the mobile node using the Home Address field of the registration request packet.

26. The method as recited in claim 13, wherein the registration request packet further includes an extension bit, the extension bit indicating that the mobile node ID is provided in a mobile node ID extension of the registration request packet when in a first state, and indicating that the mobile node ID is provided in a Home Address field of the registration request packet when in a second state, wherein obtaining the mobile node ID from the mobile node ID extension is performed when the extension bit is in the first state, the method further comprising:

obtaining the mobile node ID from an extension to the registration request packet when the extension bit is in the first state; and

obtaining the mobile node ID from the Home Address field of the registration request packet when the extension bit is in the second state.

27. A computer-readable medium storing thereon computer-readable instructions for processing a registration request packet received from a mobile node in a Home Agent, comprising:

instructions for receiving the registration request packet from a mobile node, wherein the registration request packet includes a mobile node ID extension, the mobile node ID extension specifying at least a portion of a mobile node ID associated with the mobile node;

instructions for ascertaining whether the mobile node designated by the registration request packet needs an IP address;

instructions for assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

instructions for composing a registration reply specifying the IP address assigned to the mobile node.

28. A computer-readable medium storing thereon computer-readable instructions for processing a registration reply packet received from a Home Agent in a Foreign Agent, comprising:

instructions for receiving the registration reply packet, the registration reply packet specifying at least a portion of a mobile node ID and an IP address associated with a mobile node, wherein the registration reply packet includes a Mobile Node ID extension, the portion of the mobile node ID being provided in the Mobile Node ID extension of the registration reply packet;

instructions for obtaining the portion of the mobile node ID and the IP address from the registration reply packet;

instructions for updating a visitor table with a mapping of the mobile node ID to the IP address associated with the mobile node; and

instructions for sending the registration reply packet to the mobile node.

29. In a Home Agent, a method of processing a registration request packet received from a mobile node, comprising:

receiving the registration request packet from a mobile node, wherein the registration request packet specifies at least a portion of a mobile node ID associated with the mobile node and wherein the registration request packet has a home address field, and wherein the at least a portion of the mobile node ID is specified in the home address field of the registration request packet, wherein the mobile node ID contains a number of bytes greater than that of the home address field,

ascertaining whether the mobile node designated by the at least a portion of a mobile node ID needs an IP address;

assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

composing a registration reply specifying the IP address assigned to the mobile node.

30. The method as recited in claim 29, further comprising authenticating the mobile node using the at least a portion of the mobile node ID provided in the home address field of the registration request packet.

31. A computer-readable medium storing thereon computer-readable instructions for processing a registration request packet received from a mobile node in a Home Agent, comprising:

instructions for receiving the registration request packet from a mobile node, wherein the registration request packet specifies at least a portion of a mobile node ID associated with the mobile node, wherein the registration request packet has a home address field, and wherein the at least a portion of the mobile node ID is specified in the home address field of the registration request packet, wherein the mobile node ID contains a number of bytes greater than that of the home address field;

instructions for ascertaining whether the mobile node designated by the at least a portion of a mobile node ID needs an IP address;

instructions for assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

instructions for composing a registration reply specifying the IP address assigned to the mobile node.

32. The computer-readable medium as recited in claim 31, further comprising instructions for authenticating the mobile node using the at least a portion of the mobile node ID provided in the home address field of the registration request packet.

33. In a Home Agent, a method of processing a registration request packet received from a mobile node, comprising:

receiving the registration request packet from a mobile node, wherein the registration request packet specifies a mobile node ID associated with the mobile node and wherein the registration request packet has a home address field, and wherein the mobile node ID is specified in the home address field of the registration request packet, wherein the mobile node ID contains a number of bytes less than or equal to that of the home address field;

ascertaining whether the mobile node designated by the at least a portion of a mobile node ID needs an IP address;

assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

composing a registration reply specifying the IP address assigned to the mobile node.

34. The method as recited in claim 33, further comprising authenticating the mobile node using the mobile node ID provided in the home address field of the registration request packet.

35. A computer-readable medium storing thereon computer-readable instructions for processing a registration request packet received from a mobile node in a Home Agent, comprising:

instructions for receiving the registration request packet from a mobile node, wherein the registration request packet specifies a mobile node ID associated with the mobile node and wherein the registration request packet has a home address field, and wherein the mobile node ID is specified in the home address field of the registration request packet, wherein the mobile node ID contains a number of bytes less than or equal to that of the home address field;

instructions for ascertaining whether the mobile node designated by the at least a portion of a mobile node ID needs an IP address;

instructions for assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

instructions for composing a registration reply specifying the IP address assigned to the mobile node.

36. The computer-readable medium as recited in claim 35, further comprising instructions for authenticating the mobile node using the mobile node ID provided in the home address field of the registration request packet.

37. A Home Agent adapted for processing a registration request packet received from a mobile node, comprising:

means for receiving the registration request packet from a mobile node;

means for ascertaining whether the mobile node designated by the registration request packet needs an IP address;

means for assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

means for composing a registration reply specifying the IP address assigned to the mobile node;

wherein the means for composing the registration reply comprises means for appending an IP address extension to the registration reply, the IP address extension including the IP address assigned to the mobile node.

38. A Home Agent adapted for processing a registration request packet received from a mobile node, comprising:

a processor; and

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

receiving the registration request packet from a mobile node;

ascertaining whether the mobile node designated by the registration request packet needs an IP address;

assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

composing a registration reply specifying the IP address assigned to the mobile node;

wherein composing the registration reply comprises appending an IP address extension to the registration reply, the IP address extension including the IP address assigned to the mobile node.

39. A Home Agent adapted for processing a registration request packet received from a mobile node comprising:

means for receiving the registration request packet from a mobile node, wherein the registration request packet specifies at least a portion of a mobile node ID associated with the mobile node and wherein the registration request packet has a home address field, and wherein the at least a portion of the mobile node ID is specified in the home address field of the registration request packet, wherein the mobile node ID contains a number of bytes greater than that of the home address field;

means for ascertaining whether the mobile node designated by the at least a portion of a mobile node ID needs an IP address;

means for assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

means for composing a registration reply specifying the IP address assigned to the mobile node.

40. A Home Agent adapted for processing a region request packet received from a mobile node, comprising:

a processor, and

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

receiving the registration request packet from a mobile node, wherein the registration request packet specifies at least a portion of a mobile node ID associated with the mobile node and wherein registration request packet has a home address field, and wherein the at least a portion of the mobile node ID is specified in the home address field of the registration request packet, who the mobile node ID contains a number of bytes greater than tat of the home address field;

ascertaining whet the mobile node designated by the at least a portion of a mobile node ID needs an IP address;

assigning an IP address to the mobile node if it is as ed that the mobile node needs an IP adds; and

composing a registration reply specifying the IP address assigned to the mobile node.

41. A computer-readable medium storing thereon computer-readable instructions for processing a registration request packet received from a mobile node, comprising:

instructions for receiving the registration request packet from a mobile node;

instructions for ascertaining whether the mobile node designated by the registration request packet needs an IP address;

instructions for assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

instructions for composing a registration reply specifying the IP address assigned to the mobile node, wherein the registration reply includes a Home Address field and the mobile node has a mobile node ID, wherein composing the registration reply includes

instructions for storing a portion of the mobile node ID in the Home Address field of the registration reply, wherein the mobile node ID contains a number of bytes greater than that of the Home Address field.

42. A Home Agent adapted for processing a registration request packet received from a mobile node, comprising:

a processor; and

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

receiving the registration request packet from a mobile node;

ascertaining whether the mobile node designated by the registration request packet needs an IP address;

assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

composing a registration reply specifying the IP address assigned to the mobile node, wherein the registration reply includes a Home Address field and the mobile node has a mobile node ID, wherein composing the registration reply includes storing a portion of the mobile node ID in the Home Address field of the registration reply, wherein the mobile node ID contains a number of bytes greater than that of the Home Address field.

43. A Home Agent adapted for processing a registration request packet received from a mobile node, comprising:

means for receiving the registration request packet from a mobile node;

means for ascertaining whether the mobile node designated by the registration request packet needs an IP address;

means for assigning an IP address to the mobile node if it is ascertained that the mobile node needs an IP address; and

means for composing a registration reply specifying the IP address assigned to the mobile node, wherein the registration reply includes a Home Address field and the mobile node has a mobile node ID, wherein composing the registration reply includes means for storing a portion of the mobile node ID in the Home Address field of the registration reply, wherein the mobile node ID contains a number of bytes greater than that of the Home Address field.

44. A computer-readable medium storing thereon computer-readable instructions for processing a registration reply packet received from a Home Agent, comprising:

instructions for receiving the registration reply packet, the registration reply packet specifying at least a portion of a mobile node ID and an IP address associated with a mobile node;

instructions for obtaining the portion of the mobile node ID and the IP address from the registration reply packet;

instructions for updating a visitor table with a mapping of the mobile node ID to the IP address associated with the mobile node; and

instructions for sending the registration reply packet to the mobile node, wherein the registration reply packet includes a Home Address field, the portion of the mobile node ID being provided in the Home Address field of the registration reply packet, wherein the mobile node ID contains a number of bytes greater than that of the Home Address field.

45. A Foreign Agent adapted for processing a registration reply packet received from a Home Agent, comprising:

a processor; and

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

receiving the registration reply packet, the registration reply packet specifying at least a portion of a mobile node ID and an IP address associated with a mobile node;

obtaining the portion of the mobile node ID and the IP address from the registration reply packet;

updating a visitor table with a mapping of the mobile node ID to the IP address associated with the mobile node; and

sending the registration reply packet to the mobile node, wherein the registration reply packet includes a Home Address field, the portion of the mobile node ID being provided in the Home Address field of the registration reply packet, wherein the mobile node ID contains a number of bytes greater than that of the Home Address field.

46. A Foreign Agent adapted for processing a registration reply packet received from a Home Agent, comprising:

means for receiving the registration reply packet, the registration reply packet specifying at least a portion of a mobile node ID and an IP address associated with a mobile node;

means for obtaining the portion of the mobile node ID and the IP address from the registration reply packet;

means for updating a visitor table with a mapping of the mobile node ID to the IP address associated with the mobile node; and

means for sending the registration reply packet to the mobile node, wherein the registration reply packet includes a Home Address field, the portion of the mobile node ID being provided in the Home Address field of the registration reply packet, wherein the mobile node ID contains a number of bytes greater than that of the Home Address field.