Apparatus and method for communication with a mobile communications device in an IP network

1. A system for communication with a mobile communications device in an Internet Protocol (IP) network, comprising:

an application server;

a first foreign agent and a first home agent, wherein the application server is registered to the first foreign agent and the first home agent;

a mobile communications device; and

a second foreign agent and a second home agent, wherein the mobile communications device is registered to the second foreign agent and the second home agent;

wherein the first foreign agent receives a binding notification from the second home agent through a first communication path and creates a first binding for the second foreign agent;

wherein the second foreign agent receives a binding notification from the first home agent through a second communication path and creates a second binding for the first foreign agent;

and wherein the first foreign agent communicates through a third communication path directly with the second foreign agent by utilizing the first binding and wherein the second foreign agent communicates directly with the first foreign agent through the third communication path by utilizing the second binding, wherein the third communication path does not include the first home agent and the second home agent.

2. The system of claim 1 , wherein the first foreign agent communicates directly with the second foreign agent by utilizing a mobile IP tunnel and wherein the second foreign agent communicates directly with the first foreign agent by utilizing the mobile IP tunnel.

3. The system of claim 2 , wherein the mobile IP tunnel is a User Datagram Protocol (UDP) tunnel.

4. The system of claim 2 , wherein the mobile IP tunnel is an IP-IP tunnel.

5. The system of claim 1 , wherein the first and second bindings include an IP address.

6. The system of claim 1 , wherein the first and second bindings are created in a binding cache in the respective first and second foreign agents.

7. The system of claim 1 , wherein the first home agent sends a first binding update for the first foreign agent to the second home agent, and wherein the second home agent sends a second binding update for the second foreign agent to the first home agent.

8. The system of claim 7 , wherein the first foreign agent creates the first binding for the second foreign agent by utilizing the second binding update, and wherein the second foreign agent creates the second binding for the first foreign agent by utilizing the first binding update.

9. The system of claim 1 :

wherein the first foreign agent appends a first registration extension to a first registration request sent to the first home agent;

wherein the second foreign agent appends a second registration extension to a second registration request sent to the second home agent; and

wherein the first and second registration extensions relate to a capability of the respective first and second foreign agents for route optimization.

10. The system of claim 9 :

wherein the first home agent confirms the first registration extension in a first registration reply sent to the first foreign agent; and

wherein the second home agent confirms the second registration extension in a second registration reply sent to the second foreign agent.

11. A method for communication with a mobile communications device in an Internet Protocol (IP) network, wherein the network includes:

an application server;

a first foreign agent and a first home agent, wherein the application server is registered to the first foreign agent and the first home agent; and

a second foreign agent and a second home agent, wherein the mobile communications device is registered to the second foreign agent and the second home agent;

comprising the steps of:

creating a first binding by the first foreign agent for the second foreign agent based on a binding notification received from the second home agent received through a first communication path;

creating a second binding by the second foreign agent for the first foreign agent based on a binding notification from the first home agent received through a second communication path and;

communicating directly with the second foreign agent by the first foreign agent through a third communication path by utilizing the first binding; and

communicating directly with the first foreign agent by the second foreign agent through the third communication path by utilizing the second binding,

wherein the third communication path does not include the first home agent and the second home agent.

12. The method of claim 11 , further comprising the steps of communicating directly with the second foreign agent by the first foreign agent by utilizing a mobile IP tunnel and directly communicating with the first foreign agent by the second foreign agent by utilizing the mobile IP tunnel.

13. The method of claim 12 , wherein the mobile IP tunnel is a User Datagram Protocol (UDP) tunnel.

14. The method of claim 12 , wherein the mobile IP tunnel is an IP-IP tunnel.

15. The method of claim 11 , wherein the first and second bindings include an IP address.

16. The method of claim 11 , wherein the first and second bindings are created in a binding cache in the respective first and second foreign agents.

17. The method of claim 11 , further comprising the steps of sending a first binding update for the first foreign agent to the second home agent by the first home agent and sending a second binding update for the second foreign agent to the first home agent by the second home agent.

18. The method of claim 17 , wherein the first foreign agent creates the first binding for the second foreign agent by utilizing the second binding update and wherein the second foreign agent creates the second binding for the first foreign agent by utilizing the first binding update.

19. The method of claim 11 , further comprising the steps of:

appending a first registration extension to a first registration request sent to the first home agent by the first foreign agent; and

appending a second registration extension to a second registration request sent to the second home agent by the second foreign agent;

wherein the first and second registration extensions relate to a capability of the respective first and second foreign agents for route optimization.

20. The method of claim 19 , further comprising the steps of:

confirming the first registration extension in a first registration reply sent to the first foreign agent by the first home agent; and

confirming the second registration extension in a second registration reply sent to the second foreign agent by the second home agent.