Method and program code for communicating with a mobile node through tunnels

• US 6,915,325 B1
• Filed: 01/02/2001
• Issued: 07/05/2005
• Est. Priority Date: 03/13/2000
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Lee, Cheng-Yin, Kadri, Fayaz, Morrow, Glenn
• Primary Examiner(s): Follansbee, John
• Assistant Examiner(s): Hu, Jinsong
• Application Number:
  US09/753,069
• Time in Patent Office: 1,645 Days
• Field of Search: 709/202, 709/234, 709/241, 709/245, 455/433, 455/435, 455/456, 370/313, 370/356, 370/409, 370/466
• US Class Current: 709/202
• CPC Class Codes: H04L 63/029 Firewall traversal, e.g. tunnelling or, creating pinholes
• CPC Class Codes: H04W 8/082 for traffic bypassing of mobility servers, e.g. location registers, home PLMNs or home agents
• CPC Class Codes: H04W 80/04 Network layer protocols, e.g. mobile IP [Internet Protocol]

Abstract

Location update messages for a mobile node can be made interceptible by routers which form tunnels for communication with the mobile node. A correspondent agent intercepts a Binding Update with a Router Alert and binds the address of the mobile node with a care of address for the mobile node provided in the Binding Update. The correspondent agent will thereafter intercept messages from its correspondent host destined for the mobile node and redirect them to the care of address thereby bypassing the home agent of the mobile node. A border router intercepts a Registration Request with Router Alert and binds the address of the mobile node with a care of address for the mobile node. If a binding existed previously, then the border router terminates the Request. Otherwise, the Request is forwarded to the home agent of the mobile node after substituting its own address for the care of address.

Claims

1. A method of maintaining communication access to a mobile node comprising:

intercepting, at a router, a location update message relating to the mobile node; and

binding an address of the mobile node with a care of address received in the location update message,

wherein the router is a correspondent agent for a correspondent host and wherein the act of binding forms a tunnel for messages to the mobile node that avoids a home agent of the mobile node.

2. Te method of claim 1 further comprising substituting an address of the router for the care of address in the location update message and forwarding the location update message to a home agent of the mobile node.

3. The method of claim 1 further comprising terminating the location update message.

4. The method of claim 1 wherein the mobile node is a mobile DP host.

5. A method of communicating between the mobile node and the correspondent host according to claim 1 further comprising:

receiving a data message emanating from the correspondent host; and

transmitting the data message toward the mobile node via the tunnel.

6. The method of claim 5 wherein transmitting the data message comprises encapsulating the data message with a header addressed to the care of address.

7. The method of claim 5 wherein the care of address comprises an address unique to the mobile node and transmitting the data message comprises substituting the care of address into the data message.

8. The method of claim 1 wherein the act of binding takes place in a redirector router.

9. The method of claim 8 further comprising commanding the correspondent host to send messages meant for the mobile node to the redirector router.

10. The method of claim 1 wherein the router is an agent for a mobile correspondent host.

11. A method for communicating with a mobile node traveling in a domain remote from its home agent comprising:

intercepting a location update message from the mobile node at a border router having a binding for the mobile node;

revising the binding to include a care of address received in the location update message; and

terminating the location update message.

12. A computer program product for maintaining communication access to a mobile node, the computer program product comprising a computer usable medium having computer program code thereon, said computer program code comprising:

program code for intercepting a location update message relating to the mobile node; and

program code for binding an address of the mobile node with a care of address received in the location update message, wherein the program code for binding forms a tunnel for messages to the mobile node that avoids a home agent of the mobile node.

13. The computer program product of claim 12 for use in a router further comprising program code for substituting an address of the router for the care of address in the location update message and forwarding the location update message to a home agent of the mobile node.

14. The computer program product of claim 12 further comprising program code for terminating the location update message.

15. A computer program product for communicating between the mobile node and the correspondent host according to claim 12 further comprising program code for transmitting, in response to receiving a data message emanating from the correspondent host, the data message toward the mobile node via the tunnel.

16. The computer program product of claim 15 wherein the program code for transmitting the data message comprises program code for encapsulating the data message with a header addressed to the care of address.

17. The computer program product of claim 15 wherein the care of address comprises an address unique to the mobile node and the program code for transmitting the data message comprises program code for substituting the care of address into the data message.

18. A computer program product for use in a border router in a domain where a mobile node is remote from the mobile node'"'"'s home agent, the computer program product comprising a computer usable medium having computer program code thereon, said computer program code comprising:

program code for binding an address of the mobile node with a first care of address;

program code for intercepting a location update message from the mobile node;

program code for revising the binding to replace the first care of address with a second care of address received in the location update message; and

program code for terminating the location update message, wherein the router is a correspondent agent for a correspondent host and wherein the act of binding forms a tunnel for messages to the mobile node that avoids a home agent of the mobile node.